From 2482ea1ea7819c861b04c2beb75d39f0a4a2cf97 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Fri, 3 Jul 2026 14:55:59 +0200
Subject: [PATCH 1/5] Tests: Update html5lib test data from WPT

---
 tests/phpunit/data/html5lib-tests/AUTHORS.rst |   2 +-
 tests/phpunit/data/html5lib-tests/README.md   |  18 +-
 .../tree-construction/README.md               |   2 +-
 .../tree-construction/adoption02.dat          |  17 +
 .../tree-construction/html5test-com.dat       |   2 +-
 .../tree-construction/menuitem-element.dat    |   3 +-
 .../processing-instructions.dat               | 987 ++++++++++++++++++
 .../tree-construction/scripted_adoption01.dat |  16 +
 .../tree-construction/scripted_ark.dat        |  27 +
 .../tree-construction/scripted_webkit01.dat   |  30 +
 .../tree-construction/tables01.dat            |  31 +-
 .../tree-construction/tests1.dat              |  34 +-
 .../tree-construction/tests10.dat             |  46 +-
 .../tree-construction/tests17.dat             |  10 +-
 .../tree-construction/tests18.dat             |  44 +-
 .../tree-construction/tests2.dat              |   2 +-
 .../tree-construction/tests7.dat              |  10 +-
 .../tree-construction/tests9.dat              |  52 +-
 .../tree-construction/tests_innerHTML_1.dat   |   9 +-
 .../tree-construction/void-in-phrasing.dat    | 151 +++
 .../tree-construction/webkit01.dat            |  32 +-
 .../tree-construction/webkit02.dat            | 235 ++++-
 .../includes/build-visual-html-tree.php       |   2 +-
 .../html-api/wpHtmlProcessorHtml5lib.php      |  67 +-
 24 files changed, 1672 insertions(+), 157 deletions(-)
 create mode 100644 tests/phpunit/data/html5lib-tests/tree-construction/processing-instructions.dat
 create mode 100644 tests/phpunit/data/html5lib-tests/tree-construction/scripted_adoption01.dat
 create mode 100644 tests/phpunit/data/html5lib-tests/tree-construction/scripted_ark.dat
 create mode 100644 tests/phpunit/data/html5lib-tests/tree-construction/scripted_webkit01.dat
 create mode 100644 tests/phpunit/data/html5lib-tests/tree-construction/void-in-phrasing.dat

diff --git a/tests/phpunit/data/html5lib-tests/AUTHORS.rst b/tests/phpunit/data/html5lib-tests/AUTHORS.rst
index 4a7de17ad456c..293d7fde18831 100644
--- a/tests/phpunit/data/html5lib-tests/AUTHORS.rst
+++ b/tests/phpunit/data/html5lib-tests/AUTHORS.rst
@@ -1,7 +1,7 @@
 Credits
 =======
 
-The ``html5lib`` test data is maintained by:
+The ``html5lib`` test data was originally maintained by:
 
 - James Graham
 - Geoffrey Sneddon
diff --git a/tests/phpunit/data/html5lib-tests/README.md b/tests/phpunit/data/html5lib-tests/README.md
index be775c8b497b5..f843703db8e0c 100644
--- a/tests/phpunit/data/html5lib-tests/README.md
+++ b/tests/phpunit/data/html5lib-tests/README.md
@@ -2,24 +2,28 @@
 
 This directory contains a third-party test suite used for testing the WordPress HTML API.
 
-`html5lib-tests` can be found on GitHub at [html5lib/html5lib-tests](https://github.com/html5lib/html5lib-tests).
+The html5lib tree-construction tests are maintained by the Web Platform Tests project.
+The raw `.dat` fixtures can be found on GitHub at
+[web-platform-tests/wpt/html/syntax/parsing/resources](https://github.com/web-platform-tests/wpt/tree/master/html/syntax/parsing/resources).
 
 The necessary files have been copied to this directory:
 
 - `AUTHORS.rst`
 - `LICENSE`
-- `README.md`
 - `tree-construction/README.md`
 - `tree-construction/*.dat`
 
-The version of these files was taken from the git commit with
-SHA [`a9f44960a9fedf265093d22b2aa3c7ca123727b9`](https://github.com/html5lib/html5lib-tests/commit/a9f44960a9fedf265093d22b2aa3c7ca123727b9).
+The version of the WPT-copied files was taken from the git commit with
+SHA [`c469a8a72a2ce58c04601255a45504ab9f5cc763`](https://github.com/web-platform-tests/wpt/commit/c469a8a72a2ce58c04601255a45504ab9f5cc763).
+
+The `AUTHORS.rst` and `LICENSE` files document the original `html5lib-tests`
+attribution and license.
 
 ## Updating
 
-If there have been changes to the html5lib-tests repository, this test suite can be updated. In
+If there have been changes to the Web Platform Tests repository, this test suite can be updated. In
 order to update:
 
 1. Check out the latest version of git repository mentioned above.
-1. Copy the files listed above into this directory.
-1. Update the SHA mentioned in this README file with the new html5lib-tests SHA.
+1. Copy `README.md` and `*.dat` from `html/syntax/parsing/resources/` into `tree-construction/`.
+1. Update the SHA mentioned in this README file with the new Web Platform Tests SHA.
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/README.md b/tests/phpunit/data/html5lib-tests/tree-construction/README.md
index 4737a3a867e86..5005d4ec99367 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/README.md
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/README.md
@@ -31,7 +31,7 @@ errors.
 
 Then there \*may\* be a line that says "\#document-fragment", which must
 be followed by a newline (LF), followed by a string of characters that
-indicates the context element, followed by a newline (LF). If the string 
+indicates the context element, followed by a newline (LF). If the string
 of characters starts with "svg ", the context element is in the SVG
 namespace and the substring after "svg " is the local name. If the
 string of characters starts with "math ", the context element is in the
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/adoption02.dat b/tests/phpunit/data/html5lib-tests/tree-construction/adoption02.dat
index e54d8033bac71..acd388547a1ec 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/adoption02.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/adoption02.dat
@@ -37,3 +37,20 @@
 |       <address>
 |         <a>
 |         <a>
+
+#data
+<nobr><table><marquee></table><nobr>
+#errors
+(1,6): expected-doctype-but-got-start-tag
+(1,22): unexpected-start-tag-implies-table-voodoo
+(1,30): end-tag-too-early-named
+(1,36): unexpected-start-tag-implies-end-tag
+(1,36): expected-closing-tag-but-got-eof
+#document
+| <html>
+|   <head>
+|   <body>
+|     <nobr>
+|       <marquee>
+|       <table>
+|     <nobr>
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/html5test-com.dat b/tests/phpunit/data/html5lib-tests/tree-construction/html5test-com.dat
index 48d0bf95b5572..203c77ef7a693 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/html5test-com.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/html5test-com.dat
@@ -134,7 +134,7 @@
 #new-errors
 (1:2) unexpected-question-mark-instead-of-tag-name
 #document
-| <!-- ?import namespace="foo" implementation="#bar" -->
+| <?import namespace="foo" implementation="#bar"?>
 | <html>
 |   <head>
 |   <body>
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/menuitem-element.dat b/tests/phpunit/data/html5lib-tests/tree-construction/menuitem-element.dat
index fb13c3c33b0ab..f7c8e2c3ca74e 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/menuitem-element.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/menuitem-element.dat
@@ -161,13 +161,14 @@
 #data
 <!DOCTYPE html><select><menuitem></select>
 #errors
-33: Stray start tag “menuitem”.
+1:34: ERROR: End tag 'select' isn't allowed here. Currently open tags: html, body, select, menuitem.
 #document
 | <!DOCTYPE html>
 | <html>
 |   <head>
 |   <body>
 |     <select>
+|       <menuitem>
 
 #data
 <!DOCTYPE html><option><menuitem>
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/processing-instructions.dat b/tests/phpunit/data/html5lib-tests/tree-construction/processing-instructions.dat
new file mode 100644
index 0000000000000..e450e4d2e39be
--- /dev/null
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/processing-instructions.dat
@@ -0,0 +1,987 @@
+#data
+<body><?something>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?something?>
+
+#data
+<body><?something><span>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?something?>
+|     <span>
+
+#data
+<body><?something good>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?something good?>
+
+#data
+<body><?something else is good>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?something else is good?>
+
+#data
+<body><?one><?two>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?one?>
+|     <?two?>
+
+#data
+<body><?a$><?b$><?good?>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?a$ -->
+|     <!-- ?b$ -->
+|     <?good?>
+
+#data
+<body><?hey there?>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?hey there?>
+
+#data
+<body><?hey   there?>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?hey there?>
+
+#data
+<body><?hey?there>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?hey ?there?>
+
+#data
+<body><?hey\tthere=1?>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?hey there=1?>
+
+#data
+<body><?hey\nthere=1?>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?hey there=1?>
+
+#data
+<body><?hey\rthere=1?>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?hey there=1?>
+
+#data
+<body><?hey\fthere=1?>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?hey there=1?>
+
+#data
+<body><?something ? >
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?something ? ?>
+
+#data
+<body><?something x >
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?something x ?>
+
+#data
+<body><?something ?\t   ??>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?something ?\t   ??>
+
+#data
+<body><?t d > ?>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?t d ?>
+|     " ?>"
+
+#data
+<body><?module-handler>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?module-handler?>
+
+#data
+<body><?module-handler data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?module-handler data?>
+
+#data
+<body><?view-port>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?view-port?>
+
+#data
+<body><?view-port data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?view-port data?>
+
+#data
+<body><?config-v2>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?config-v2?>
+
+#data
+<body><?config-v2 data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?config-v2 data?>
+
+#data
+<body><?x>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?x?>
+
+#data
+<body><?x data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?x data?>
+
+#data
+<body><?zz2op>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?zz2op?>
+
+#data
+<body><?zz2op data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?zz2op data?>
+
+#data
+<body><?xla->
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?xla-?>
+
+#data
+<body><?xla- data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?xla- data?>
+
+#data
+<body><?a-b-c>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?a-b-c?>
+
+#data
+<body><?a-b-c data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?a-b-c data?>
+
+#data
+<body><?v-123>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?v-123?>
+
+#data
+<body><?v-123 data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?v-123 data?>
+
+#data
+<body><?a0-b1-c2>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?a0-b1-c2?>
+
+#data
+<body><?a0-b1-c2 data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?a0-b1-c2 data?>
+
+#data
+<body><?page-404>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?page-404?>
+
+#data
+<body><?page-404 data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?page-404 data?>
+
+#data
+<body><?r2-d2>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?r2-d2?>
+
+#data
+<body><?r2-d2 data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?r2-d2 data?>
+
+#data
+<body><?level-99>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?level-99?>
+
+#data
+<body><?level-99 data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?level-99 data?>
+
+#data
+<body><?UPPERCASE>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?UPPERCASE?>
+
+#data
+<body><?UPPERCASE data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?UPPERCASE data?>
+
+#data
+<body><?all-KINDS-of-CaSeS>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?all-KINDS-of-CaSeS?>
+
+#data
+<body><?all-KINDS-of-CaSeS data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?all-KINDS-of-CaSeS data?>
+
+#data
+<body><?user_name>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?user_name?>
+
+#data
+<body><?user_name data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?user_name data?>
+
+#data
+<body><?S_S-S_S>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?S_S-S_S?>
+
+#data
+<body><?S_S-S_S data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?S_S-S_S data?>
+
+#data
+<body><?b_>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?b_?>
+
+#data
+<body><?b_ data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?b_ data?>
+
+#data
+<body><?_prefix>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?_prefix?>
+
+#data
+<body><?_prefix data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?_prefix data?>
+
+#data
+<body><?_x132>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?_x132?>
+
+#data
+<body><?_x132 data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?_x132 data?>
+
+#data
+<body><?_-_>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?_-_?>
+
+#data
+<body><?_-_ data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?_-_ data?>
+
+#data
+<body><?_>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?_?>
+
+#data
+<body><?_ data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?_ data?>
+
+#data
+<body><?A---------------->
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?A----------------?>
+
+#data
+<body><?A---------------- data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?A---------------- data?>
+
+#data
+<body><?z0123456789>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?z0123456789?>
+
+#data
+<body><?z0123456789 data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?z0123456789 data?>
+
+#data
+<body><?m-0>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?m-0?>
+
+#data
+<body><?m-0 data>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <?m-0 data?>
+
+#data
+<body><?xml>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?xml -->
+
+#data
+<body><?xml-stylesheet>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?xml-stylesheet -->
+
+#data
+<body><?XML>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?XML -->
+
+#data
+<body><?XML-stylesheet>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?XML-stylesheet -->
+
+#data
+<body><?xML>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?xML -->
+
+#data
+<body><?xml-STYLesheet>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?xml-STYLesheet -->
+
+#data
+<body><?1st-place>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?1st-place -->
+
+#data
+<body><?2-factor>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?2-factor -->
+
+#data
+<body><?99-problems>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?99-problems -->
+
+#data
+<body><?\u0665-star>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?٥-star -->
+
+#data
+<body><?-prefix>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?-prefix -->
+
+#data
+<body><?--internal>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?--internal -->
+
+#data
+<body><?-data->
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?-data- -->
+
+#data
+<body><?-100>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?-100 -->
+
+#data
+<body><?\u00B7middle-dot>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?·middle-dot -->
+
+#data
+<body><?\u0375greek-numeral>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?͵greek-numeral -->
+
+#data
+<body><?\u0301accent-start>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?́accent-start -->
+
+#data
+<body><?price$value>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?price$value -->
+
+#data
+<body><?user@domain>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?user@domain -->
+
+#data
+<body><?tag#id>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?tag#id -->
+
+#data
+<body><?a+b>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?a+b -->
+
+#data
+<body><?100%>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?100% -->
+
+#data
+<body><?data.v1>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?data.v1 -->
+
+#data
+<body><?namespace:tag>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?namespace:tag -->
+
+#data
+<body><?error!code>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?error!code -->
+
+#data
+<body><?x=y>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?x=y -->
+
+#data
+<body><?a<b>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?a<b -->
+
+#data
+<body><?true&false>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?true&false -->
+
+#data
+<body><?not|or>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?not|or -->
+
+#data
+<body><?lit$123456789>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?lit$123456789 -->
+
+#data
+<body><?lit$$4x>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?lit$$4x -->
+
+#data
+<body><?\uD83D\uDE80-launch>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?🚀-launch -->
+
+#data
+<body><?error-\u26A0\uFE0F>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?error-⚠️ -->
+
+#data
+<body><?fire-\uD83D\uDD25>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?fire-🔥 -->
+
+#data
+<body><?v1-\u2705>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?v1-✅ -->
+
+#data
+<body><?start
+#document
+| <html>
+|   <head>
+|   <body>
+
+#data
+<body><?start?
+#document
+| <html>
+|   <head>
+|   <body>
+
+#data
+<body><?start 
+#document
+| <html>
+|   <head>
+|   <body>
+
+#data
+<body><?start data
+#document
+| <html>
+|   <head>
+|   <body>
+
+#data
+<body><?start ? ?
+#document
+| <html>
+|   <head>
+|   <body>
+
+#data
+<body><?
+#document
+| <html>
+|   <head>
+|   <body>
+
+#data
+<body><? 
+#document
+| <html>
+|   <head>
+|   <body>
+|     <!-- ?  -->
+
+#data
+<div><?something></div>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <div>
+|       <?something?>
+
+#data
+<div><?something good></div>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <div>
+|       <?something good?>
+
+#data
+<table><?something></table>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <table>
+|       <?something?>
+
+#data
+<table><tr><?something></tr></table>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <table>
+|       <tbody>
+|         <tr>
+|           <?something?>
+
+#data
+<script><?something></script>
+#document
+| <html>
+|   <head>
+|     <script>
+|       "<?something>"
+|   <body>
+
+#data
+<style><?something></style>
+#document
+| <html>
+|   <head>
+|     <style>
+|       "<?something>"
+|   <body>
+
+#data
+<?something>
+#document
+| <?something?>
+| <html>
+|   <head>
+|   <body>
+
+#data
+<head><?something>
+#document
+| <html>
+|   <head>
+|     <?something?>
+|   <body>
+
+#data
+<html><?something><head>
+#document
+| <html>
+|   <?something?>
+|   <head>
+|   <body>
+
+#data
+<html><head></head><?something><body>
+#document
+| <html>
+|   <head>
+|   <?something?>
+|   <body>
+
+#data
+<html><body></body><?something>
+#document
+| <html>
+|   <head>
+|   <body>
+|   <?something?>
+
+#data
+<html><body></body></html><?something>
+#document
+| <html>
+|   <head>
+|   <body>
+| <?something?>
+
+#data
+<body><template><?something></template>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <template>
+|       content
+|         <?something?>
+
+#data
+<body><textarea><?something></textarea>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <textarea>
+|       "<?something>"
+
+#data
+<body><title><?something></title>
+#document
+| <html>
+|   <head>
+|   <body>
+|     <title>
+|       "<?something>"
+
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/scripted_adoption01.dat b/tests/phpunit/data/html5lib-tests/tree-construction/scripted_adoption01.dat
new file mode 100644
index 0000000000000..5cc0f07496a65
--- /dev/null
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/scripted_adoption01.dat
@@ -0,0 +1,16 @@
+#data
+<p><b id="A"><script>document.getElementById("A").id = "B"</script></p>TEXT</b>
+#errors
+#script-on
+#document
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       <b>
+|         id="B"
+|         <script>
+|           "document.getElementById("A").id = "B""
+|     <b>
+|       id="A"
+|       "TEXT"
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/scripted_ark.dat b/tests/phpunit/data/html5lib-tests/tree-construction/scripted_ark.dat
new file mode 100644
index 0000000000000..feebeadba1d8a
--- /dev/null
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/scripted_ark.dat
@@ -0,0 +1,27 @@
+#data
+<p><font size=4><font size=4><font size=4><script>document.getElementsByTagName("font")[2].setAttribute("size", "5");</script><font size=4><p>X
+#errors
+#script-on
+#document
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       <font>
+|         size="4"
+|         <font>
+|           size="4"
+|           <font>
+|             size="5"
+|             <script>
+|               "document.getElementsByTagName("font")[2].setAttribute("size", "5");"
+|             <font>
+|               size="4"
+|     <p>
+|       <font>
+|         size="4"
+|         <font>
+|           size="4"
+|           <font>
+|             size="4"
+|             "X"
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/scripted_webkit01.dat b/tests/phpunit/data/html5lib-tests/tree-construction/scripted_webkit01.dat
new file mode 100644
index 0000000000000..3e71c1baccc9b
--- /dev/null
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/scripted_webkit01.dat
@@ -0,0 +1,30 @@
+#data
+1<script>document.write("2")</script>3
+#errors
+#script-on
+#document
+| <html>
+|   <head>
+|   <body>
+|     "1"
+|     <script>
+|       "document.write("2")"
+|     "23"
+
+#data
+1<script>document.write("<script>document.write('2')</scr"+ "ipt><script>document.write('3')</scr" + "ipt>")</script>4
+#errors
+#script-on
+#document
+| <html>
+|   <head>
+|   <body>
+|     "1"
+|     <script>
+|       "document.write("<script>document.write('2')</scr"+ "ipt><script>document.write('3')</scr" + "ipt>")"
+|     <script>
+|       "document.write('2')"
+|     "2"
+|     <script>
+|       "document.write('3')"
+|     "34"
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tables01.dat b/tests/phpunit/data/html5lib-tests/tree-construction/tables01.dat
index aa7915ebba7ea..4079888161887 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/tables01.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/tables01.dat
@@ -100,8 +100,11 @@
 #data
 <table><select><option>3</select></table>
 #errors
-(1,7): expected-doctype-but-got-start-tag
-(1,15): unexpected-start-tag-implies-table-voodoo
+1:1: ERROR: Expected a doctype token
+1:8: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, table.
+1:16: ERROR: Start tag 'option' isn't allowed here. Currently open tags: html, body, table, select.
+1:24: ERROR: Character tokens aren't legal here
+1:25: ERROR: End tag 'select' isn't allowed here. Currently open tags: html, body, table, select, option.
 #document
 | <html>
 |   <head>
@@ -114,12 +117,11 @@
 #data
 <table><select><table></table></select></table>
 #errors
-(1,7): expected-doctype-but-got-start-tag
-(1,15): unexpected-start-tag-implies-table-voodoo
-(1,22): unexpected-table-element-start-tag-in-select-in-table
-(1,22): unexpected-start-tag-implies-end-tag
-(1,39): unexpected-end-tag
-(1,47): unexpected-end-tag
+1:1: ERROR: Expected a doctype token
+1:8: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, table.
+1:16: ERROR: Start tag 'table' isn't allowed here. Currently open tags: html, body, table, select.
+1:31: ERROR: End tag 'select' isn't allowed here. Currently open tags: html, body.
+1:40: ERROR: End tag 'table' isn't allowed here. Currently open tags: html, body.
 #document
 | <html>
 |   <head>
@@ -131,9 +133,8 @@
 #data
 <table><select></table>
 #errors
-(1,7): expected-doctype-but-got-start-tag
-(1,15): unexpected-start-tag-implies-table-voodoo
-(1,23): unexpected-table-element-end-tag-in-select-in-table
+1:1: ERROR: Expected a doctype token
+1:8: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, table.
 #document
 | <html>
 |   <head>
@@ -144,9 +145,10 @@
 #data
 <table><select><option>A<tr><td>B</td></tr></table>
 #errors
-(1,7): expected-doctype-but-got-start-tag
-(1,15): unexpected-start-tag-implies-table-voodoo
-(1,28): unexpected-table-element-start-tag-in-select-in-table
+1:1: ERROR: Expected a doctype token
+1:8: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, table.
+1:16: ERROR: Start tag 'option' isn't allowed here. Currently open tags: html, body, table, select.
+1:24: ERROR: Character tokens aren't legal here
 #document
 | <html>
 |   <head>
@@ -292,7 +294,6 @@
 1:13: 'svg' tag isn't allowed here. Currently open tags: html, body, div, table.
 1:33: 'select' tag isn't allowed here. Currently open tags: html, body, div, table, svg, foreignobject.
 1:41: 'table' tag isn't allowed here. Currently open tags: html, body, div, table, svg, foreignobject, select.
-1:41: 'table' tag isn't allowed here. Currently open tags: html, body, div, table, svg, foreignobject.
 1:48: 's' tag isn't allowed here. Currently open tags: html, body, div, table.
 1:51: Premature end of file. Currently open tags: html, body, div, table, s.
 #document
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests1.dat b/tests/phpunit/data/html5lib-tests/tree-construction/tests1.dat
index e80e64016d919..4f956e93f3e03 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/tests1.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/tests1.dat
@@ -355,19 +355,20 @@ Line1<br>Line2<br>Line3<br>Line4
 #data
 <select><b><option><select><option></b></select>X
 #errors
-(1,8): expected-doctype-but-got-start-tag
-(1,11): unexpected-start-tag-in-select
-(1,27): unexpected-select-in-select
-(1,39): unexpected-end-tag
-(1,48): unexpected-end-tag
+1:1: ERROR: Expected a doctype token
+1:20: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select, b, option.
+1:36: ERROR: End tag 'b' isn't allowed here. Currently open tags: html, body, b, select, option.
+1:50: ERROR: Premature end of file. Currently open tags: html, body, b.
 #document
 | <html>
 |   <head>
 |   <body>
 |     <select>
+|       <b>
+|         <option>
+|     <b>
 |       <option>
-|     <option>
-|       "X"
+|     "X"
 
 #data
 <a><table><td><a><table></table><a></tr><a></table><b>X</b>C<a>Y
@@ -555,7 +556,6 @@ Line1<br>Line2<br>Line3<br>Line4
 #new-errors
 (1:2) unexpected-question-mark-instead-of-tag-name
 #document
-| <!-- ? -->
 | <html>
 |   <head>
 |   <body>
@@ -568,7 +568,6 @@ Line1<br>Line2<br>Line3<br>Line4
 #new-errors
 (1:2) unexpected-question-mark-instead-of-tag-name
 #document
-| <!-- ?# -->
 | <html>
 |   <head>
 |   <body>
@@ -607,7 +606,7 @@ Line1<br>Line2<br>Line3<br>Line4
 #new-errors
 (1:2) unexpected-question-mark-instead-of-tag-name
 #document
-| <!-- ?COMMENT? -->
+| <?COMMENT ??>
 | <html>
 |   <head>
 |   <body>
@@ -646,7 +645,7 @@ Line1<br>Line2<br>Line3<br>Line4
 #new-errors
 (1:2) unexpected-question-mark-instead-of-tag-name
 #document
-| <!-- ?COM--MENT? -->
+| <?COM--MENT ??>
 | <html>
 |   <head>
 |   <body>
@@ -1532,18 +1531,19 @@ Line1<br>Line2<br>Line3<br>Line4
 #data
 <select><b><option><select><option></b></select>
 #errors
-(1,8): expected-doctype-but-got-start-tag
-(1,11): unexpected-start-tag-in-select
-(1,27): unexpected-select-in-select
-(1,39): unexpected-end-tag
-(1,48): unexpected-end-tag
+1:1: ERROR: Expected a doctype token
+1:20: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select, b, option.
+1:36: ERROR: End tag 'b' isn't allowed here. Currently open tags: html, body, b, select, option.
+1:49: ERROR: Premature end of file. Currently open tags: html, body, b.
 #document
 | <html>
 |   <head>
 |   <body>
 |     <select>
+|       <b>
+|         <option>
+|     <b>
 |       <option>
-|     <option>
 
 #data
 <html><head><title></title><body></body></html>
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests10.dat b/tests/phpunit/data/html5lib-tests/tree-construction/tests10.dat
index f84e2d546fab6..3b311e4e03cd8 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/tests10.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/tests10.dat
@@ -35,20 +35,17 @@
 #data
 <!DOCTYPE html><body><select><svg></svg></select>
 #errors
-(1,34) unexpected-start-tag-in-select
-(1,40) unexpected-end-tag-in-select
 #document
 | <!DOCTYPE html>
 | <html>
 |   <head>
 |   <body>
 |     <select>
+|       <svg svg>
 
 #data
 <!DOCTYPE html><body><select><option><svg></svg></option></select>
 #errors
-(1,42) unexpected-start-tag-in-select
-(1,48) unexpected-end-tag-in-select
 #document
 | <!DOCTYPE html>
 | <html>
@@ -56,6 +53,7 @@
 |   <body>
 |     <select>
 |       <option>
+|         <svg svg>
 
 #data
 <!DOCTYPE html><body><table><svg></svg></table>
@@ -261,13 +259,8 @@
 #data
 <!DOCTYPE html><body><table><tr><td><select><svg><g>foo</g><g>bar</g><p>baz</table><p>quux
 #errors
-(1,49) unexpected-start-tag-in-select
-(1,52) unexpected-start-tag-in-select
-(1,59) unexpected-end-tag-in-select
-(1,62) unexpected-start-tag-in-select
-(1,69) unexpected-end-tag-in-select
-(1,72) unexpected-start-tag-in-select
-(1,83) unexpected-table-element-end-tag-in-select-in-table
+1:70: ERROR: Start tag 'p' isn't allowed here. Currently open tags: html, body, table, tbody, tr, td, select, svg.
+1:76: ERROR: End tag 'table' isn't allowed here. Currently open tags: html, body, table, tbody, tr, td, select.
 #document
 | <!DOCTYPE html>
 | <html>
@@ -278,28 +271,39 @@
 |         <tr>
 |           <td>
 |             <select>
-|               "foobarbaz"
+|               <svg svg>
+|                 <svg g>
+|                   "foo"
+|                 <svg g>
+|                   "bar"
+|               <p>
+|                 "baz"
 |     <p>
 |       "quux"
 
 #data
 <!DOCTYPE html><body><table><select><svg><g>foo</g><g>bar</g><p>baz</table><p>quux
 #errors
-(1,36) unexpected-start-tag-implies-table-voodoo
-(1,41) unexpected-start-tag-in-select
-(1,44) unexpected-start-tag-in-select
-(1,51) unexpected-end-tag-in-select
-(1,54) unexpected-start-tag-in-select
-(1,61) unexpected-end-tag-in-select
-(1,64) unexpected-start-tag-in-select
-(1,75) unexpected-table-element-end-tag-in-select-in-table
+1:29: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, table.
+1:37: ERROR: Start tag 'svg' isn't allowed here. Currently open tags: html, body, table, select.
+1:62: ERROR: Start tag 'p' isn't allowed here. Currently open tags: html, body, table, select, svg.
+1:62: ERROR: Start tag 'p' isn't allowed here. Currently open tags: html, body, table, select.
+1:65: ERROR: Character tokens aren't legal here
+1:66: ERROR: Character tokens aren't legal here
+1:67: ERROR: Character tokens aren't legal here
 #document
 | <!DOCTYPE html>
 | <html>
 |   <head>
 |   <body>
 |     <select>
-|       "foobarbaz"
+|       <svg svg>
+|         <svg g>
+|           "foo"
+|         <svg g>
+|           "bar"
+|       <p>
+|         "baz"
 |     <table>
 |     <p>
 |       "quux"
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests17.dat b/tests/phpunit/data/html5lib-tests/tree-construction/tests17.dat
index e49bcf03142dc..1c472d1dc1eb8 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/tests17.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/tests17.dat
@@ -1,9 +1,8 @@
 #data
 <!doctype html><table><tbody><select><tr>
 #errors
-(1,37): unexpected-start-tag-implies-table-voodoo
-(1,41): unexpected-table-element-start-tag-in-select-in-table
-(1,41): eof-in-table
+(1,30): unexpected-start-tag
+(1,42): premature-eof
 #document
 | <!DOCTYPE html>
 | <html>
@@ -17,9 +16,8 @@
 #data
 <!doctype html><table><tr><select><td>
 #errors
-(1,34): unexpected-start-tag-implies-table-voodoo
-(1,38): unexpected-table-element-start-tag-in-select-in-table
-(1,38): expected-closing-tag-but-got-eof
+(1,27): unexpected-start-tag
+(1,39): premature-eof
 #document
 | <!DOCTYPE html>
 | <html>
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests18.dat b/tests/phpunit/data/html5lib-tests/tree-construction/tests18.dat
index 0b6d5dc404a9d..a3bb69a16ef57 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/tests18.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/tests18.dat
@@ -227,34 +227,42 @@
 #data
 <!doctype html><select><plaintext></plaintext>X
 #errors
-34: Stray start tag “plaintext”.
-46: Stray end tag “plaintext”.
-47: End of file seen and there were open elements.
+1:48: ERROR: Premature end of file. Currently open tags: html, body, select, plaintext.
 #document
 | <!DOCTYPE html>
 | <html>
 |   <head>
 |   <body>
 |     <select>
-|       "X"
+|       <plaintext>
+|         "</plaintext>X"
 
 #data
 <!doctype html><table><select><plaintext>a<caption>b
 #errors
-30: Start tag “select” seen in “table”.
-41: Stray start tag “plaintext”.
-51: “caption” start tag with “select” open.
-52: End of file seen and there were open elements.
+1:23: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, table.
+1:31: ERROR: Start tag 'plaintext' isn't allowed here. Currently open tags: html, body, table, select.
+1:42: ERROR: Character tokens aren't legal here
+1:43: ERROR: Character tokens aren't legal here
+1:44: ERROR: Character tokens aren't legal here
+1:45: ERROR: Character tokens aren't legal here
+1:46: ERROR: Character tokens aren't legal here
+1:47: ERROR: Character tokens aren't legal here
+1:48: ERROR: Character tokens aren't legal here
+1:49: ERROR: Character tokens aren't legal here
+1:50: ERROR: Character tokens aren't legal here
+1:51: ERROR: Character tokens aren't legal here
+1:52: ERROR: Character tokens aren't legal here
+1:53: ERROR: Premature end of file. Currently open tags: html, body, table, select, plaintext.
 #document
 | <!DOCTYPE html>
 | <html>
 |   <head>
 |   <body>
 |     <select>
-|       "a"
+|       <plaintext>
+|         "a<caption>b"
 |     <table>
-|       <caption>
-|         "b"
 
 #data
 <!doctype html><template><plaintext>a</template>b
@@ -446,8 +454,11 @@
 #data
 <!doctype html><table><select><script></style></script>abc
 #errors
-(1,30): unexpected-start-tag-implies-table-voodoo
-(1,58): eof-in-select
+1:23: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, table.
+1:56: ERROR: Character tokens aren't legal here
+1:57: ERROR: Character tokens aren't legal here
+1:58: ERROR: Character tokens aren't legal here
+1:59: ERROR: Premature end of file. Currently open tags: html, body, table, select.
 #document
 | <!DOCTYPE html>
 | <html>
@@ -462,8 +473,11 @@
 #data
 <!doctype html><table><tr><select><script></style></script>abc
 #errors
-(1,34): unexpected-start-tag-implies-table-voodoo
-(1,62): eof-in-select
+1:27: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, table, tbody, tr.
+1:60: ERROR: Character tokens aren't legal here
+1:61: ERROR: Character tokens aren't legal here
+1:62: ERROR: Character tokens aren't legal here
+1:63: ERROR: Premature end of file. Currently open tags: html, body, table, tbody, tr, select.
 #document
 | <!DOCTYPE html>
 | <html>
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests2.dat b/tests/phpunit/data/html5lib-tests/tree-construction/tests2.dat
index 11ef9b1643ff4..9232edde30918 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/tests2.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/tests2.dat
@@ -500,7 +500,7 @@
 #data
 <!DOCTYPE html><select><optgroup><option></optgroup><option><select><option>
 #errors
-(1,68): unexpected-select-in-select
+1:61: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select, option.
 #document
 | <!DOCTYPE html>
 | <html>
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests7.dat b/tests/phpunit/data/html5lib-tests/tree-construction/tests7.dat
index b2db4de1f3bdf..aa7e16b408e2e 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/tests7.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/tests7.dat
@@ -200,7 +200,7 @@ X</listing>
 #data
 <!doctype html><select><input>X
 #errors
-(1,30): unexpected-input-in-select
+1:32: ERROR: Premature end of file. Currently open tags: html, body, select.
 #document
 | <!DOCTYPE html>
 | <html>
@@ -213,7 +213,7 @@ X</listing>
 #data
 <!doctype html><select><select>X
 #errors
-(1,31): unexpected-select-in-select
+1:24: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select.
 #document
 | <!DOCTYPE html>
 | <html>
@@ -443,11 +443,11 @@ A<table><tr> B</tr> </em>C</table>
 #data
 <select><keygen>
 #errors
-(1,8): expected-doctype-but-got-start-tag
-(1,16): unexpected-input-in-select
+1:1: ERROR: Expected a doctype token
+1:17: ERROR: Premature end of file. Currently open tags: html, body, select.
 #document
 | <html>
 |   <head>
 |   <body>
 |     <select>
-|     <keygen>
+|       <keygen>
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests9.dat b/tests/phpunit/data/html5lib-tests/tree-construction/tests9.dat
index f8d04b23bc0be..1456324ffc21f 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/tests9.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/tests9.dat
@@ -48,20 +48,17 @@
 #data
 <!DOCTYPE html><body><select><math></math></select>
 #errors
-(1,35) unexpected-start-tag-in-select
-(1,42) unexpected-end-tag-in-select
 #document
 | <!DOCTYPE html>
 | <html>
 |   <head>
 |   <body>
 |     <select>
+|       <math math>
 
 #data
 <!DOCTYPE html><body><select><option><math></math></option></select>
 #errors
-(1,43) unexpected-start-tag-in-select
-(1,50) unexpected-end-tag-in-select
 #document
 | <!DOCTYPE html>
 | <html>
@@ -69,6 +66,7 @@
 |   <body>
 |     <select>
 |       <option>
+|         <math math>
 
 #data
 <!DOCTYPE html><body><table><math></math></table>
@@ -301,13 +299,8 @@
 #data
 <!DOCTYPE html><body><table><tr><td><select><math><mi>foo</mi><mi>bar</mi><p>baz</table><p>quux
 #errors
-(1,50) unexpected-start-tag-in-select
-(1,54) unexpected-start-tag-in-select
-(1,62) unexpected-end-tag-in-select
-(1,66) unexpected-start-tag-in-select
-(1,74) unexpected-end-tag-in-select
-(1,77) unexpected-start-tag-in-select
-(1,88) unexpected-table-element-end-tag-in-select-in-table
+1:75: ERROR: Start tag 'p' isn't allowed here. Currently open tags: html, body, table, tbody, tr, td, select, math.
+1:81: ERROR: End tag 'table' isn't allowed here. Currently open tags: html, body, table, tbody, tr, td, select.
 #document
 | <!DOCTYPE html>
 | <html>
@@ -318,28 +311,45 @@
 |         <tr>
 |           <td>
 |             <select>
-|               "foobarbaz"
+|               <math math>
+|                 <math mi>
+|                   "foo"
+|                 <math mi>
+|                   "bar"
+|               <p>
+|                 "baz"
 |     <p>
 |       "quux"
 
 #data
 <!DOCTYPE html><body><table><select><math><mi>foo</mi><mi>bar</mi><p>baz</table><p>quux
 #errors
-(1,36) unexpected-start-tag-implies-table-voodoo
-(1,42) unexpected-start-tag-in-select
-(1,46) unexpected-start-tag-in-select
-(1,54) unexpected-end-tag-in-select
-(1,58) unexpected-start-tag-in-select
-(1,66) unexpected-end-tag-in-select
-(1,69) unexpected-start-tag-in-select
-(1,80) unexpected-table-element-end-tag-in-select-in-table
+1:29: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, table.
+1:37: ERROR: Start tag 'math' isn't allowed here. Currently open tags: html, body, table, select.
+1:47: ERROR: Character tokens aren't legal here
+1:48: ERROR: Character tokens aren't legal here
+1:49: ERROR: Character tokens aren't legal here
+1:59: ERROR: Character tokens aren't legal here
+1:60: ERROR: Character tokens aren't legal here
+1:61: ERROR: Character tokens aren't legal here
+1:67: ERROR: Start tag 'p' isn't allowed here. Currently open tags: html, body, table, select, math.
+1:67: ERROR: Start tag 'p' isn't allowed here. Currently open tags: html, body, table, select.
+1:70: ERROR: Character tokens aren't legal here
+1:71: ERROR: Character tokens aren't legal here
+1:72: ERROR: Character tokens aren't legal here
 #document
 | <!DOCTYPE html>
 | <html>
 |   <head>
 |   <body>
 |     <select>
-|       "foobarbaz"
+|       <math math>
+|         <math mi>
+|           "foo"
+|         <math mi>
+|           "bar"
+|       <p>
+|         "baz"
 |     <table>
 |     <p>
 |       "quux"
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests_innerHTML_1.dat b/tests/phpunit/data/html5lib-tests/tree-construction/tests_innerHTML_1.dat
index 1a37ee520ae34..09e0456f0f12d 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/tests_innerHTML_1.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/tests_innerHTML_1.dat
@@ -790,7 +790,7 @@ select
 #data
 <input><option>
 #errors
-(1,7): unexpected-input-in-select
+(1,7): XXX-undefined-error
 #document-fragment
 select
 #document
@@ -799,20 +799,21 @@ select
 #data
 <keygen><option>
 #errors
-(1,8): unexpected-input-in-select
 #document-fragment
 select
 #document
+| <keygen>
 | <option>
 
 #data
 <textarea><option>
 #errors
-(1,10): unexpected-input-in-select
+1:19: ERROR: Premature end of file. Currently open tags: html, textarea.
 #document-fragment
 select
 #document
-| <option>
+| <textarea>
+|   "<option>"
 
 #data
 </html><!--abc-->
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/void-in-phrasing.dat b/tests/phpunit/data/html5lib-tests/tree-construction/void-in-phrasing.dat
new file mode 100644
index 0000000000000..b7dbd1e7cec2a
--- /dev/null
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/void-in-phrasing.dat
@@ -0,0 +1,151 @@
+#data
+<!DOCTYPE html><body><p><br></p>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       <br>
+
+#data
+<!DOCTYPE html><body><p><br>text</p>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       <br>
+|       "text"
+
+#data
+<!DOCTYPE html><body><p>before<br>after</p>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       "before"
+|       <br>
+|       "after"
+
+#data
+<!DOCTYPE html><body><p><br><br></p>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       <br>
+|       <br>
+
+#data
+<!DOCTYPE html><body><p>a<br>b<br>c</p>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       "a"
+|       <br>
+|       "b"
+|       <br>
+|       "c"
+
+#data
+<!DOCTYPE html><body><h1><br></h1>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <h1>
+|       <br>
+
+#data
+<!DOCTYPE html><body><p><input></p>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       <input>
+
+#data
+<!DOCTYPE html><body><p><img></p>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       <img>
+
+#data
+<!DOCTYPE html><body><p><wbr></p>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       <wbr>
+
+#data
+<!DOCTYPE html><body><p><embed></p>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <p>
+|       <embed>
+
+#data
+<!DOCTYPE html><body><h2><input></h2>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <h2>
+|       <input>
+
+#data
+<!DOCTYPE html><body><em><br></em>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <em>
+|       <br>
+
+#data
+<!DOCTYPE html><body><strong><br>text</strong>
+#errors
+#document
+| <!DOCTYPE html>
+| <html>
+|   <head>
+|   <body>
+|     <strong>
+|       <br>
+|       "text"
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/webkit01.dat b/tests/phpunit/data/html5lib-tests/tree-construction/webkit01.dat
index d30e12e52766e..fc7f5c80e07e4 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/webkit01.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/webkit01.dat
@@ -437,11 +437,11 @@ no-doctype
 #data
 <select><option>A<select><option>B<select><option>C<select><option>D<select><option>E<select><option>F<select><option>G<select>
 #errors
-(1,8): expected-doctype-but-got-start-tag
-(1,25): unexpected-select-in-select
-(1,59): unexpected-select-in-select
-(1,93): unexpected-select-in-select
-(1,127): unexpected-select-in-select
+1:1: ERROR: Expected a doctype token
+1:18: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select, option.
+1:52: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select, option.
+1:86: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select, option.
+1:120: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select, option.
 #document
 | <html>
 |   <head>
@@ -528,12 +528,11 @@ no-doctype
 #data
 <kbd><table></kbd><col><select><tr>
 #errors
-(1,5): expected-doctype-but-got-start-tag
-(1,18): unexpected-end-tag-implies-table-voodoo
-(1,18): unexpected-end-tag
-(1,31): unexpected-start-tag-implies-table-voodoo
-(1,35): unexpected-table-element-start-tag-in-select-in-table
-(1,35): eof-in-table
+1:1: ERROR: Expected a doctype token
+1:13: ERROR: End tag 'kbd' isn't allowed here. Currently open tags: html, body, kbd, table.
+1:13: ERROR: End tag 'kbd' isn't allowed here. Currently open tags: html, body, kbd, table.
+1:24: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, kbd, table.
+1:36: ERROR: Premature end of file. Currently open tags: html, body, kbd, table, tbody, tr.
 #document
 | <html>
 |   <head>
@@ -549,12 +548,11 @@ no-doctype
 #data
 <kbd><table></kbd><col><select><tr></table><div>
 #errors
-(1,5): expected-doctype-but-got-start-tag
-(1,18): unexpected-end-tag-implies-table-voodoo
-(1,18): unexpected-end-tag
-(1,31): unexpected-start-tag-implies-table-voodoo
-(1,35): unexpected-table-element-start-tag-in-select-in-table
-(1,48): expected-closing-tag-but-got-eof
+1:1: ERROR: Expected a doctype token
+1:13: ERROR: End tag 'kbd' isn't allowed here. Currently open tags: html, body, kbd, table.
+1:13: ERROR: End tag 'kbd' isn't allowed here. Currently open tags: html, body, kbd, table.
+1:24: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, kbd, table.
+1:49: ERROR: Premature end of file. Currently open tags: html, body, kbd, div.
 #document
 | <html>
 |   <head>
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/webkit02.dat b/tests/phpunit/data/html5lib-tests/tree-construction/webkit02.dat
index 7d817ec69a700..47a3c5713ea86 100644
--- a/tests/phpunit/data/html5lib-tests/tree-construction/webkit02.dat
+++ b/tests/phpunit/data/html5lib-tests/tree-construction/webkit02.dat
@@ -309,12 +309,13 @@ div
 #data
 <option><XH<optgroup></optgroup>
 #errors
-(1,21): unexpected-start-tag-in-select
-(1,32): unexpected-end-tag-in-select
+1:22: ERROR: End tag 'optgroup' isn't allowed here. Currently open tags: html, option, xh<optgroup.
+1:33: ERROR: Premature end of file. Currently open tags: html, option, xh<optgroup.
 #document-fragment
 select
 #document
 | <option>
+|   <xh<optgroup>
 
 #data
 <svg><foreignObject><div>foo</div><plaintext></foreignObject></svg><div>bar</div>
@@ -444,7 +445,7 @@ eof-in-math
 <select><optgroup><hr>
 #errors
 1:1: ERROR: Expected a doctype token
-1:23: ERROR: Premature end of file. Currently open tags: html, body, select.
+1:23: ERROR: Premature end of file. Currently open tags: html, body, select, optgroup.
 #document
 | <html>
 |   <head>
@@ -457,7 +458,7 @@ eof-in-math
 <select><option><optgroup><hr>
 #errors
 1:1: ERROR: Expected a doctype token
-1:31: ERROR: Premature end of file. Currently open tags: html, body, select.
+1:31: ERROR: Premature end of file. Currently open tags: html, body, select, optgroup.
 #document
 | <html>
 |   <head>
@@ -504,7 +505,7 @@ eof-in-math
 <table><tr><td><select><optgroup><option><hr>
 #errors
 1:1: ERROR: Expected a doctype token
-1:46: ERROR: Premature end of file. Currently open tags: html, body, table, tbody, tr, td, select.
+1:46: ERROR: Premature end of file. Currently open tags: html, body, table, tbody, tr, td, select, optgroup.
 #document
 | <html>
 |   <head>
@@ -522,7 +523,7 @@ eof-in-math
 <table><tr><td><select><optgroup><hr>
 #errors
 1:1: ERROR: Expected a doctype token
-1:38: ERROR: Premature end of file. Currently open tags: html, body, table, tbody, tr, td, select.
+1:38: ERROR: Premature end of file. Currently open tags: html, body, table, tbody, tr, td, select, optgroup.
 #document
 | <html>
 |   <head>
@@ -539,7 +540,7 @@ eof-in-math
 <table><tr><td><select><option><optgroup><hr>
 #errors
 1:1: ERROR: Expected a doctype token
-1:46: ERROR: Premature end of file. Currently open tags: html, body, table, tbody, tr, td, select.
+1:38: ERROR: Premature end of file. Currently open tags: html, body, table, tbody, tr, td, select, optgroup.
 #document
 | <html>
 |   <head>
@@ -552,3 +553,223 @@ eof-in-math
 |               <option>
 |               <optgroup>
 |               <hr>
+
+#data
+<select><div><i></div><option>option
+#errors
+1:1: ERROR: Expected a doctype token
+1:17: ERROR: End tag 'div' isn't allowed here. Currently open tags: html, body, select, div, i.
+1:37: ERROR: Premature end of file. Currently open tags: html, body, select, option, i.
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <div>
+|         <i>
+|       <i>
+|         <option>
+|           "option"
+
+#data
+<div><i></div><option>option
+#errors
+1:1: ERROR: Expected a doctype token
+1:9: ERROR: End tag 'div' isn't allowed here. Currently open tags: html, body, div, i.
+1:29: ERROR: Premature end of file. Currently open tags: html, body, i, option.
+#document
+| <html>
+|   <head>
+|   <body>
+|     <div>
+|       <i>
+|     <i>
+|       <option>
+|         "option"
+
+#data
+<select><div>div 1</div><button>button</button><div>div 2</div><datalist><option>option</option></datalist><div>div 3</div></select>
+#errors
+1:1: ERROR: Expected a doctype token
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <div>
+|         "div 1"
+|       <button>
+|         "button"
+|       <div>
+|         "div 2"
+|       <datalist>
+|         <option>
+|           "option"
+|       <div>
+|         "div 3"
+
+#data
+<select><button>button</select>
+#errors
+1:1: ERROR: Expected a doctype token
+1:23: ERROR: End tag 'select' isn't allowed here. Currently open tags: html, body, select, button.
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <button>
+|         "button"
+
+#data
+<select><datalist>datalist</select>
+#errors
+1:1: ERROR: Expected a doctype token
+1:27: ERROR: End tag 'select' isn't allowed here. Currently open tags: html, body, select, datalist.
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <datalist>
+|         "datalist"
+
+#data
+<select><button><select></select></button></select>
+#errors
+1:1: ERROR: Expected a doctype token
+1:17: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select, button.
+1:25: ERROR: End tag 'select' isn't allowed here. Currently open tags: html, body.
+1:34: ERROR: End tag 'button' isn't allowed here. Currently open tags: html, body.
+1:43: ERROR: End tag 'select' isn't allowed here. Currently open tags: html, body.
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <button>
+
+#data
+<select><button><div><select></select>
+#errors
+1:1: ERROR: Expected a doctype token
+1:22: ERROR: Start tag 'select' isn't allowed here. Currently open tags: html, body, select, button, div.
+1:30: ERROR: End tag 'select' isn't allowed here. Currently open tags: html, body.
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <button>
+|         <div>
+
+#data
+<select><div><option><img>option</option></div></select>
+#errors
+1:1: ERROR: Expected a doctype token
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <div>
+|         <option>
+|           <img>
+|           "option"
+
+#data
+<select><input>
+#errors
+1:1: ERROR: Expected a doctype token
+1:16: ERROR: Premature end of file. Currently open tags: html, body, select.
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|     <input>
+
+#data
+<select><button><selectedcontent></button><option>X
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <button>
+|         <selectedcontent>
+|           "X"
+|       <option>
+|         "X"
+
+#data
+<select><button><selectedcontent></button><option>x<i>i<b>ib</i>b
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <button>
+|         <selectedcontent>
+|           "x"
+|           <i>
+|             "i"
+|             <b>
+|               "ib"
+|           <b>
+|             "b"
+|       <option>
+|         "x"
+|         <i>
+|           "i"
+|           <b>
+|             "ib"
+|         <b>
+|           "b"
+
+#data
+<select><button><selectedcontent></button><option>X<option>Y
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <button>
+|         <selectedcontent>
+|           "X"
+|       <option>
+|         "X"
+|       <option>
+|         "Y"
+
+#data
+<select><button><selectedcontent></button><option>X<option selected>Y
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <button>
+|         <selectedcontent>
+|           "Y"
+|       <option>
+|         "X"
+|       <option>
+|         selected=""
+|         "Y"
+
+#data
+<font><select><option>a</option></font></select>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <font>
+|       <select>
+|         <option>
+|           "a"
diff --git a/tests/phpunit/includes/build-visual-html-tree.php b/tests/phpunit/includes/build-visual-html-tree.php
index 9d2850ce4947c..85578d9d735bc 100644
--- a/tests/phpunit/includes/build-visual-html-tree.php
+++ b/tests/phpunit/includes/build-visual-html-tree.php
@@ -34,7 +34,7 @@
  *         style="margin-top:50px;margin-bottom:50px;"
  *
  *
- * @see https://github.com/WordPress/wordpress-develop/blob/trunk/tests/phpunit/data/html5lib-tests/tree-construction/README.md
+ * @see https://github.com/web-platform-tests/wpt/blob/master/html/syntax/parsing/resources/README.md
  *
  * @since 6.9.0
  *
diff --git a/tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php b/tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php
index d87d784dbf2d4..575f7c52d6a82 100644
--- a/tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php
+++ b/tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php
@@ -6,9 +6,9 @@
  * This test suite runs a set of tests on the HTML API using a third-party suite of test fixtures.
  * A third-party test suite allows the HTML API's behavior to be compared against an external
  * standard. Without a third-party, there is risk of oversight or misinterpretation of the standard
- * being implemented in application code and in tests. html5lib-tests is used by other projects like
- * browsers or other HTML parsers for the same purpose of validating behavior against an
- * external reference.
+ * being implemented in application code and in tests. The html5lib tree-construction tests are
+ * used by other projects like browsers or other HTML parsers for the same purpose of validating
+ * behavior against an external reference.
  *
  * See the README file at DIR_TESTDATA / html5lib-tests for details on the third-party suite.
  *
@@ -27,22 +27,51 @@ class Tests_HtmlApi_Html5lib extends WP_UnitTestCase {
 	 * Skip specific tests that may not be supported or have known issues.
 	 */
 	const SKIP_TESTS = array(
-		'noscript01/line0014' => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'tests14/line0022'    => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'tests14/line0055'    => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'tests19/line0488'    => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'tests19/line0500'    => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'tests19/line1079'    => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'tests2/line0207'     => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'tests2/line0686'     => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'tests2/line0697'     => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'tests2/line0709'     => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
-		'webkit01/line0231'   => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'noscript01/line0014'       => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests14/line0022'          => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests14/line0055'          => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests19/line0488'          => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests19/line0500'          => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests19/line1079'          => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests2/line0207'           => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests2/line0686'           => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests2/line0697'           => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests2/line0709'           => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'tests1/line0601'           => 'Unimplemented: This parser treats processing instructions as comments.',
+		'tests1/line0640'           => 'Unimplemented: This parser treats processing instructions as comments.',
+		'html5test-com/line0129'    => 'Unimplemented: This parser treats processing instructions as comments.',
+		'menuitem-element/line0161' => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'tests9/line0048'           => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'tests9/line0059'           => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'tests9/line0299'           => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'tests10/line0035'          => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'tests10/line0046'          => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'tests10/line0259'          => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'tests18/line0227'          => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit01/line0231'         => 'Unimplemented: This parser does not add missing attributes to existing HTML or BODY tags.',
+		'webkit02/line0557'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0590'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0611'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0624'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0637'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0652'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0666'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0692'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0706'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0732'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+		'webkit02/line0748'         => 'Unimplemented: This parser does not support customizable SELECT element content.',
+	);
+
+	/**
+	 * Skip test files that exercise parser behavior unsupported by the HTML API.
+	 */
+	const SKIP_TEST_PREFIXES = array(
+		'processing-instructions/' => 'Unimplemented: This parser treats processing instructions as comments.',
 	);
 
 	/**
 	 * Verify the parsing results of the HTML Processor against the
-	 * test cases in the Html5lib tests project.
+	 * test cases in the Web Platform Tests html5lib tree-construction suite.
 	 *
 	 * @ticket 60227
 	 *
@@ -98,7 +127,7 @@ public function test_parse( ?string $fragment_context, string $html, string $exp
 	/**
 	 * Data provider.
 	 *
-	 * Tests from https://github.com/html5lib/html5lib-tests
+	 * Tests from https://github.com/web-platform-tests/wpt/tree/master/html/syntax/parsing/resources
 	 *
 	 * @return array[]
 	 */
@@ -146,6 +175,12 @@ private static function should_skip_test( ?string $test_context_element, string
 			return true;
 		}
 
+		foreach ( array_keys( self::SKIP_TEST_PREFIXES ) as $test_prefix ) {
+			if ( str_starts_with( $test_name, $test_prefix ) ) {
+				return true;
+			}
+		}
+
 		return false;
 	}
 

From 082b840e3a463c2bc32c05fdd1ecf6ff0b2e1904 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Fri, 3 Jul 2026 16:19:38 +0200
Subject: [PATCH 2/5] Tests: Rename HTML API external suite to WPT

---
 phpunit.xml.dist                              |   2 +-
 .../.gitattributes                            |   0
 .../AUTHORS.rst                               |   0
 .../LICENSE                                   |   0
 .../README.md                                 |   6 ++--
 .../tree-construction/README.md               |   0
 .../tree-construction/adoption01.dat          |   0
 .../tree-construction/adoption02.dat          |   0
 .../tree-construction/blocks.dat              |   0
 .../tree-construction/comments01.dat          |   0
 .../tree-construction/doctype01.dat           |   0
 .../tree-construction/domjs-unsafe.dat        | Bin
 .../tree-construction/entities01.dat          |   0
 .../tree-construction/entities02.dat          |   0
 .../tree-construction/foreign-fragment.dat    |   0
 .../tree-construction/html5test-com.dat       |   0
 .../tree-construction/inbody01.dat            |   0
 .../tree-construction/isindex.dat             |   0
 .../tree-construction/main-element.dat        |   0
 .../tree-construction/math.dat                |   0
 .../tree-construction/menuitem-element.dat    |   0
 .../namespace-sensitivity.dat                 |   0
 .../tree-construction/noscript01.dat          |   0
 ...pending-spec-changes-plain-text-unsafe.dat | Bin
 .../pending-spec-changes.dat                  |   0
 .../tree-construction/plain-text-unsafe.dat   | Bin
 .../processing-instructions.dat               |   0
 .../tree-construction/quirks01.dat            |   0
 .../tree-construction/ruby.dat                |   0
 .../tree-construction/scriptdata01.dat        |   0
 .../tree-construction/scripted_adoption01.dat |   0
 .../tree-construction/scripted_ark.dat        |   0
 .../tree-construction/scripted_webkit01.dat   |   0
 .../tree-construction/search-element.dat      |   0
 .../tree-construction/svg.dat                 |   0
 .../tree-construction/tables01.dat            |   0
 .../tree-construction/template.dat            |   0
 .../tree-construction/tests1.dat              |   0
 .../tree-construction/tests10.dat             |   0
 .../tree-construction/tests11.dat             |   0
 .../tree-construction/tests12.dat             |   0
 .../tree-construction/tests14.dat             |   0
 .../tree-construction/tests15.dat             |   0
 .../tree-construction/tests16.dat             |   0
 .../tree-construction/tests17.dat             |   0
 .../tree-construction/tests18.dat             |   0
 .../tree-construction/tests19.dat             |   0
 .../tree-construction/tests2.dat              |   0
 .../tree-construction/tests20.dat             |   0
 .../tree-construction/tests21.dat             |   0
 .../tree-construction/tests22.dat             |   0
 .../tree-construction/tests23.dat             |   0
 .../tree-construction/tests24.dat             |   0
 .../tree-construction/tests25.dat             |   0
 .../tree-construction/tests26.dat             |   0
 .../tree-construction/tests3.dat              |   0
 .../tree-construction/tests4.dat              |   0
 .../tree-construction/tests5.dat              |   0
 .../tree-construction/tests6.dat              |   0
 .../tree-construction/tests7.dat              |   0
 .../tree-construction/tests8.dat              |   0
 .../tree-construction/tests9.dat              |   0
 .../tree-construction/tests_innerHTML_1.dat   |   0
 .../tree-construction/tricky01.dat            |   0
 .../tree-construction/void-in-phrasing.dat    |   0
 .../tree-construction/webkit01.dat            |   0
 .../tree-construction/webkit02.dat            |   0
 .../includes/build-visual-html-tree.php       |   2 +-
 tests/phpunit/multisite.xml                   |   2 +-
 .../tests/html-api/wpHtmlProcessor.php        |   4 +--
 ...hp => wpHtmlProcessorWebPlatformTests.php} |  30 +++++++++---------
 71 files changed, 23 insertions(+), 23 deletions(-)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/.gitattributes (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/AUTHORS.rst (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/LICENSE (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/README.md (85%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/README.md (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/adoption01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/adoption02.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/blocks.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/comments01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/doctype01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/domjs-unsafe.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/entities01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/entities02.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/foreign-fragment.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/html5test-com.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/inbody01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/isindex.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/main-element.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/math.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/menuitem-element.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/namespace-sensitivity.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/noscript01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/pending-spec-changes-plain-text-unsafe.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/pending-spec-changes.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/plain-text-unsafe.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/processing-instructions.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/quirks01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/ruby.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/scriptdata01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/scripted_adoption01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/scripted_ark.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/scripted_webkit01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/search-element.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/svg.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tables01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/template.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests1.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests10.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests11.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests12.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests14.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests15.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests16.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests17.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests18.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests19.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests2.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests20.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests21.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests22.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests23.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests24.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests25.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests26.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests3.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests4.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests5.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests6.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests7.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests8.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests9.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tests_innerHTML_1.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/tricky01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/void-in-phrasing.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/webkit01.dat (100%)
 rename tests/phpunit/data/{html5lib-tests => web-platform-tests}/tree-construction/webkit02.dat (100%)
 rename tests/phpunit/tests/html-api/{wpHtmlProcessorHtml5lib.php => wpHtmlProcessorWebPlatformTests.php} (94%)

diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 4b6c149867c7d..2b1a8c9dab784 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -29,7 +29,7 @@
 			<group>ms-files</group>
 			<group>ms-required</group>
 			<group>external-http</group>
-			<group>html-api-html5lib-tests</group>
+			<group>html-api-web-platform-tests</group>
 		</exclude>
 	</groups>
 	<logging>
diff --git a/tests/phpunit/data/html5lib-tests/.gitattributes b/tests/phpunit/data/web-platform-tests/.gitattributes
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/.gitattributes
rename to tests/phpunit/data/web-platform-tests/.gitattributes
diff --git a/tests/phpunit/data/html5lib-tests/AUTHORS.rst b/tests/phpunit/data/web-platform-tests/AUTHORS.rst
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/AUTHORS.rst
rename to tests/phpunit/data/web-platform-tests/AUTHORS.rst
diff --git a/tests/phpunit/data/html5lib-tests/LICENSE b/tests/phpunit/data/web-platform-tests/LICENSE
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/LICENSE
rename to tests/phpunit/data/web-platform-tests/LICENSE
diff --git a/tests/phpunit/data/html5lib-tests/README.md b/tests/phpunit/data/web-platform-tests/README.md
similarity index 85%
rename from tests/phpunit/data/html5lib-tests/README.md
rename to tests/phpunit/data/web-platform-tests/README.md
index f843703db8e0c..874ae275b2dfd 100644
--- a/tests/phpunit/data/html5lib-tests/README.md
+++ b/tests/phpunit/data/web-platform-tests/README.md
@@ -1,8 +1,8 @@
-# html5lib-tests
+# Web Platform Tests
 
 This directory contains a third-party test suite used for testing the WordPress HTML API.
 
-The html5lib tree-construction tests are maintained by the Web Platform Tests project.
+The tree-construction tests are maintained by the Web Platform Tests project.
 The raw `.dat` fixtures can be found on GitHub at
 [web-platform-tests/wpt/html/syntax/parsing/resources](https://github.com/web-platform-tests/wpt/tree/master/html/syntax/parsing/resources).
 
@@ -16,7 +16,7 @@ The necessary files have been copied to this directory:
 The version of the WPT-copied files was taken from the git commit with
 SHA [`c469a8a72a2ce58c04601255a45504ab9f5cc763`](https://github.com/web-platform-tests/wpt/commit/c469a8a72a2ce58c04601255a45504ab9f5cc763).
 
-The `AUTHORS.rst` and `LICENSE` files document the original `html5lib-tests`
+The `AUTHORS.rst` and `LICENSE` files document the original html5lib test suite
 attribution and license.
 
 ## Updating
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/README.md b/tests/phpunit/data/web-platform-tests/tree-construction/README.md
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/README.md
rename to tests/phpunit/data/web-platform-tests/tree-construction/README.md
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/adoption01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/adoption01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/adoption01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/adoption01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/adoption02.dat b/tests/phpunit/data/web-platform-tests/tree-construction/adoption02.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/adoption02.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/adoption02.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/blocks.dat b/tests/phpunit/data/web-platform-tests/tree-construction/blocks.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/blocks.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/blocks.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/comments01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/comments01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/comments01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/comments01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/doctype01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/doctype01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/doctype01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/doctype01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/domjs-unsafe.dat b/tests/phpunit/data/web-platform-tests/tree-construction/domjs-unsafe.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/domjs-unsafe.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/domjs-unsafe.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/entities01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/entities01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/entities01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/entities01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/entities02.dat b/tests/phpunit/data/web-platform-tests/tree-construction/entities02.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/entities02.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/entities02.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/foreign-fragment.dat b/tests/phpunit/data/web-platform-tests/tree-construction/foreign-fragment.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/foreign-fragment.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/foreign-fragment.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/html5test-com.dat b/tests/phpunit/data/web-platform-tests/tree-construction/html5test-com.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/html5test-com.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/html5test-com.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/inbody01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/inbody01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/inbody01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/inbody01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/isindex.dat b/tests/phpunit/data/web-platform-tests/tree-construction/isindex.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/isindex.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/isindex.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/main-element.dat b/tests/phpunit/data/web-platform-tests/tree-construction/main-element.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/main-element.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/main-element.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/math.dat b/tests/phpunit/data/web-platform-tests/tree-construction/math.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/math.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/math.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/menuitem-element.dat b/tests/phpunit/data/web-platform-tests/tree-construction/menuitem-element.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/menuitem-element.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/menuitem-element.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/namespace-sensitivity.dat b/tests/phpunit/data/web-platform-tests/tree-construction/namespace-sensitivity.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/namespace-sensitivity.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/namespace-sensitivity.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/noscript01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/noscript01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/noscript01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/noscript01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/pending-spec-changes-plain-text-unsafe.dat b/tests/phpunit/data/web-platform-tests/tree-construction/pending-spec-changes-plain-text-unsafe.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/pending-spec-changes-plain-text-unsafe.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/pending-spec-changes-plain-text-unsafe.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/pending-spec-changes.dat b/tests/phpunit/data/web-platform-tests/tree-construction/pending-spec-changes.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/pending-spec-changes.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/pending-spec-changes.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/plain-text-unsafe.dat b/tests/phpunit/data/web-platform-tests/tree-construction/plain-text-unsafe.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/plain-text-unsafe.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/plain-text-unsafe.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/processing-instructions.dat b/tests/phpunit/data/web-platform-tests/tree-construction/processing-instructions.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/processing-instructions.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/processing-instructions.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/quirks01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/quirks01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/quirks01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/quirks01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/ruby.dat b/tests/phpunit/data/web-platform-tests/tree-construction/ruby.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/ruby.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/ruby.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/scriptdata01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/scriptdata01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/scriptdata01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/scriptdata01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/scripted_adoption01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/scripted_adoption01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/scripted_adoption01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/scripted_adoption01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/scripted_ark.dat b/tests/phpunit/data/web-platform-tests/tree-construction/scripted_ark.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/scripted_ark.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/scripted_ark.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/scripted_webkit01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/scripted_webkit01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/scripted_webkit01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/scripted_webkit01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/search-element.dat b/tests/phpunit/data/web-platform-tests/tree-construction/search-element.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/search-element.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/search-element.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/svg.dat b/tests/phpunit/data/web-platform-tests/tree-construction/svg.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/svg.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/svg.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tables01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tables01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tables01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tables01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/template.dat b/tests/phpunit/data/web-platform-tests/tree-construction/template.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/template.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/template.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests1.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests1.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests1.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests1.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests10.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests10.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests10.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests10.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests11.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests11.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests11.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests11.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests12.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests12.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests12.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests12.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests14.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests14.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests14.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests14.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests15.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests15.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests15.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests15.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests16.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests16.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests16.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests16.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests17.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests17.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests17.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests17.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests18.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests18.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests18.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests18.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests19.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests19.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests19.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests19.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests2.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests2.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests2.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests2.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests20.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests20.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests20.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests20.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests21.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests21.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests21.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests21.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests22.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests22.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests22.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests22.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests23.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests23.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests23.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests23.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests24.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests24.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests24.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests24.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests25.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests25.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests25.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests25.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests26.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests26.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests26.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests26.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests3.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests3.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests3.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests3.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests4.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests4.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests4.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests4.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests5.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests5.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests5.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests5.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests6.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests6.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests6.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests6.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests7.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests7.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests7.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests7.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests8.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests8.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests8.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests8.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests9.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests9.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests9.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests9.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tests_innerHTML_1.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tests_innerHTML_1.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tests_innerHTML_1.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tests_innerHTML_1.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/tricky01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/tricky01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/tricky01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/tricky01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/void-in-phrasing.dat b/tests/phpunit/data/web-platform-tests/tree-construction/void-in-phrasing.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/void-in-phrasing.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/void-in-phrasing.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/webkit01.dat b/tests/phpunit/data/web-platform-tests/tree-construction/webkit01.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/webkit01.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/webkit01.dat
diff --git a/tests/phpunit/data/html5lib-tests/tree-construction/webkit02.dat b/tests/phpunit/data/web-platform-tests/tree-construction/webkit02.dat
similarity index 100%
rename from tests/phpunit/data/html5lib-tests/tree-construction/webkit02.dat
rename to tests/phpunit/data/web-platform-tests/tree-construction/webkit02.dat
diff --git a/tests/phpunit/includes/build-visual-html-tree.php b/tests/phpunit/includes/build-visual-html-tree.php
index 85578d9d735bc..4fa5bd0abeb69 100644
--- a/tests/phpunit/includes/build-visual-html-tree.php
+++ b/tests/phpunit/includes/build-visual-html-tree.php
@@ -119,7 +119,7 @@ function build_visual_html_tree( string $html, ?string $fragment_context ): stri
 					}
 
 					/*
-					 * Sorts attributes to match html5lib sort order.
+					 * Sorts attributes to match Web Platform Tests tree-construction order.
 					 *
 					 *  - First comes normal HTML attributes.
 					 *  - Then come adjusted foreign attributes; these have spaces in their names.
diff --git a/tests/phpunit/multisite.xml b/tests/phpunit/multisite.xml
index 50b98540f329d..1ab518cea15dc 100644
--- a/tests/phpunit/multisite.xml
+++ b/tests/phpunit/multisite.xml
@@ -34,7 +34,7 @@
 			<group>ms-excluded</group>
 			<group>external-http</group>
 			<group>oembed-headers</group>
-			<group>html-api-html5lib-tests</group>
+			<group>html-api-web-platform-tests</group>
 		</exclude>
 	</groups>
 	<filter>
diff --git a/tests/phpunit/tests/html-api/wpHtmlProcessor.php b/tests/phpunit/tests/html-api/wpHtmlProcessor.php
index 8cece32438bd3..a978422c20098 100644
--- a/tests/phpunit/tests/html-api/wpHtmlProcessor.php
+++ b/tests/phpunit/tests/html-api/wpHtmlProcessor.php
@@ -644,7 +644,7 @@ public function test_foreign_content_script_self_closing() {
 	/**
 	 * Ensures that the HTML Processor correctly handles TEMPLATE tag closing and namespaces.
 	 *
-	 * This is a tricky test case that corresponds to the html5lib tests "template/line1466".
+	 * This is a tricky test case that corresponds to the Web Platform Tests fixture "template/line1466".
 	 *
 	 * When the `</template>` token is reached it is in the HTML namespace (thanks to the
 	 * SVG `foreignObject` element). It is not handled as foreign content; therefore, it
@@ -652,7 +652,7 @@ public function test_foreign_content_script_self_closing() {
 	 * SVG `TEMPLATE` element (the second `<template>` token).
 	 *
 	 * The test is included here because it may show up as unsupported markup and be skipped by
-	 * the html5lib test suite.
+	 * the Web Platform Tests suite.
 	 *
 	 * @ticket 61576
 	 */
diff --git a/tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php b/tests/phpunit/tests/html-api/wpHtmlProcessorWebPlatformTests.php
similarity index 94%
rename from tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php
rename to tests/phpunit/tests/html-api/wpHtmlProcessorWebPlatformTests.php
index 575f7c52d6a82..633477d2dac0f 100644
--- a/tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php
+++ b/tests/phpunit/tests/html-api/wpHtmlProcessorWebPlatformTests.php
@@ -6,11 +6,11 @@
  * This test suite runs a set of tests on the HTML API using a third-party suite of test fixtures.
  * A third-party test suite allows the HTML API's behavior to be compared against an external
  * standard. Without a third-party, there is risk of oversight or misinterpretation of the standard
- * being implemented in application code and in tests. The html5lib tree-construction tests are
- * used by other projects like browsers or other HTML parsers for the same purpose of validating
- * behavior against an external reference.
+ * being implemented in application code and in tests. The Web Platform Tests tree-construction
+ * fixtures are used by other projects like browsers or other HTML parsers for the same purpose
+ * of validating behavior against an external reference.
  *
- * See the README file at DIR_TESTDATA / html5lib-tests for details on the third-party suite.
+ * See the README file at DIR_TESTDATA / web-platform-tests for details on the third-party suite.
  *
  * @package WordPress
  * @subpackage HTML-API
@@ -18,9 +18,9 @@
  * @since 6.6.0
  *
  * @group html-api
- * @group html-api-html5lib-tests
+ * @group html-api-web-platform-tests
  */
-class Tests_HtmlApi_Html5lib extends WP_UnitTestCase {
+class Tests_HtmlApi_WebPlatformTests extends WP_UnitTestCase {
 	const TREE_INDENT = '  ';
 
 	/**
@@ -71,11 +71,11 @@ class Tests_HtmlApi_Html5lib extends WP_UnitTestCase {
 
 	/**
 	 * Verify the parsing results of the HTML Processor against the
-	 * test cases in the Web Platform Tests html5lib tree-construction suite.
+	 * test cases in the Web Platform Tests tree-construction suite.
 	 *
 	 * @ticket 60227
 	 *
-	 * @dataProvider data_external_html5lib_tests
+	 * @dataProvider data_external_web_platform_tests
 	 *
 	 * @param string|null $fragment_context Context element in which to parse HTML, such as BODY or SVG.
 	 * @param string      $html             Given test HTML.
@@ -131,8 +131,8 @@ public function test_parse( ?string $fragment_context, string $html, string $exp
 	 *
 	 * @return array[]
 	 */
-	public function data_external_html5lib_tests() {
-		$test_dir = DIR_TESTDATA . '/html5lib-tests/tree-construction/';
+	public function data_external_web_platform_tests() {
+		$test_dir = DIR_TESTDATA . '/web-platform-tests/tree-construction/';
 
 		$handle = opendir( $test_dir );
 		while ( false !== ( $entry = readdir( $handle ) ) ) {
@@ -140,7 +140,7 @@ public function data_external_html5lib_tests() {
 				continue;
 			}
 
-			foreach ( self::parse_html5_dat_testfile( $test_dir . $entry ) as $k => $test ) {
+			foreach ( self::parse_web_platform_test_file( $test_dir . $entry ) as $k => $test ) {
 				// strip .dat extension from filename
 				$test_suite = substr( $entry, 0, -4 );
 				$line       = str_pad( strval( $test[0] ), 4, '0', STR_PAD_LEFT );
@@ -185,7 +185,7 @@ private static function should_skip_test( ?string $test_context_element, string
 	}
 
 	/**
-	 * Generates the tree-like structure represented in the Html5lib tests.
+	 * Generates the tree-like structure represented in the Web Platform Tests fixtures.
 	 *
 	 * @param string|null $fragment_context Context element in which to parse HTML, such as BODY or SVG.
 	 * @param string      $html             Given test HTML.
@@ -263,7 +263,7 @@ private static function build_tree_representation( ?string $fragment_context, st
 						}
 
 						/*
-						 * Sorts attributes to match html5lib sort order.
+						 * Sorts attributes to match Web Platform Tests tree-construction order.
 						 *
 						 *  - First comes normal HTML attributes.
 						 *  - Then come adjusted foreign attributes; these have spaces in their names.
@@ -373,7 +373,7 @@ static function ( $a, $b ) {
 	}
 
 	/**
-	 * Convert a given Html5lib test file into a series of test cases.
+	 * Convert a given Web Platform Tests fixture file into a series of test cases.
 	 *
 	 * @param string $filename Path to `.dat` file with test cases.
 	 *
@@ -384,7 +384,7 @@ static function ( $a, $b ) {
 	 *     string,           // DOM structure it represents.
 	 * }> Test cases.
 	 */
-	public static function parse_html5_dat_testfile( $filename ) {
+	public static function parse_web_platform_test_file( $filename ) {
 		$handle = fopen( $filename, 'r', false );
 
 		/**

From f3c7b3e21ed6530aac7a63000bf149f9597e3678 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Fri, 3 Jul 2026 16:35:11 +0200
Subject: [PATCH 3/5] Tests: Update WPT workflow group name

---
 .github/workflows/phpunit-tests.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/phpunit-tests.yml b/.github/workflows/phpunit-tests.yml
index f46b419656a44..b387ebacd0874 100644
--- a/.github/workflows/phpunit-tests.yml
+++ b/.github/workflows/phpunit-tests.yml
@@ -252,7 +252,7 @@ jobs:
         php: [ '7.4', '8.0', '8.4' ]
         db-type: [ 'mysql' ]
         db-version: [ '8.4' ]
-        phpunit-test-groups: [ 'html-api-html5lib-tests' ]
+        phpunit-test-groups: [ 'html-api-web-platform-tests' ]
         # A matrix value is needed in the 'name' directive for proper grouping in the GitHub UI.
         label: [ 'HTML API' ]
     with:
@@ -305,7 +305,7 @@ jobs:
           - php: '8.4'
             db-version: '9.7'
             db-type: 'mysql'
-            phpunit-test-groups: 'html-api-html5lib-tests'
+            phpunit-test-groups: 'html-api-web-platform-tests'
 
         exclude:
           # Exclude PHP versions that are not supported by the database versions.

From f51e56deabcbc891e56e546a2f352f77808ec1b7 Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Fri, 3 Jul 2026 20:12:33 +0200
Subject: [PATCH 4/5] Update and rename test structure

---
 .../data/web-platform-tests/AUTHORS.rst       |  34 --
 tests/phpunit/data/web-platform-tests/LICENSE |  21 --
 .../data/web-platform-tests/LICENSE.md        |  11 +
 .../phpunit/data/web-platform-tests/README.md |  22 +-
 .../README.md                                 |   0
 .../adoption01.dat                            |   0
 .../adoption02.dat                            |   0
 .../blocks.dat                                |   0
 .../comments01.dat                            |   0
 .../html_syntax_parsing_resources/common.js   |  24 ++
 .../doctype01.dat                             |   0
 .../domjs-unsafe.dat                          | Bin
 .../entities01.dat                            |   0
 .../entities02.dat                            |   0
 .../foreign-fragment.dat                      |   0
 .../html5test-com.dat                         |   0
 .../inbody01.dat                              |   0
 .../isindex.dat                               |   0
 .../main-element.dat                          |   0
 .../math.dat                                  |   0
 .../menuitem-element.dat                      |   0
 .../namespace-sensitivity.dat                 |   0
 .../noscript01.dat                            |   0
 ...pending-spec-changes-plain-text-unsafe.dat | Bin
 .../pending-spec-changes.dat                  |   0
 .../plain-text-unsafe.dat                     | Bin
 .../processing-instructions.dat               |   0
 .../quirks01.dat                              |   0
 .../ruby.dat                                  |   0
 .../scriptdata01.dat                          |   0
 .../scripted_adoption01.dat                   |   0
 .../scripted_ark.dat                          |   0
 .../scripted_webkit01.dat                     |   0
 .../search-element.dat                        |   0
 .../svg.dat                                   |   0
 .../tables01.dat                              |   0
 .../template.dat                              |   0
 .../html_syntax_parsing_resources/template.js | 214 +++++++++++
 .../html_syntax_parsing_resources/test.js     | 337 ++++++++++++++++++
 .../tests1.dat                                |   0
 .../tests10.dat                               |   0
 .../tests11.dat                               |   0
 .../tests12.dat                               |   0
 .../tests14.dat                               |   0
 .../tests15.dat                               |   0
 .../tests16.dat                               |   0
 .../tests17.dat                               |   0
 .../tests18.dat                               |   0
 .../tests19.dat                               |   0
 .../tests2.dat                                |   0
 .../tests20.dat                               |   0
 .../tests21.dat                               |   0
 .../tests22.dat                               |   0
 .../tests23.dat                               |   0
 .../tests24.dat                               |   0
 .../tests25.dat                               |   0
 .../tests26.dat                               |   0
 .../tests3.dat                                |   0
 .../tests4.dat                                |   0
 .../tests5.dat                                |   0
 .../tests6.dat                                |   0
 .../tests7.dat                                |   0
 .../tests8.dat                                |   0
 .../tests9.dat                                |   0
 .../tests_innerHTML_1.dat                     |   0
 .../tricky01.dat                              |   0
 .../void-in-phrasing.dat                      |   0
 .../webkit01.dat                              |   0
 .../webkit02.dat                              |   0
 69 files changed, 592 insertions(+), 71 deletions(-)
 delete mode 100644 tests/phpunit/data/web-platform-tests/AUTHORS.rst
 delete mode 100644 tests/phpunit/data/web-platform-tests/LICENSE
 create mode 100644 tests/phpunit/data/web-platform-tests/LICENSE.md
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/README.md (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/adoption01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/adoption02.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/blocks.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/comments01.dat (100%)
 create mode 100644 tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/common.js
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/doctype01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/domjs-unsafe.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/entities01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/entities02.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/foreign-fragment.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/html5test-com.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/inbody01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/isindex.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/main-element.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/math.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/menuitem-element.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/namespace-sensitivity.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/noscript01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/pending-spec-changes-plain-text-unsafe.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/pending-spec-changes.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/plain-text-unsafe.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/processing-instructions.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/quirks01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/ruby.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/scriptdata01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/scripted_adoption01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/scripted_ark.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/scripted_webkit01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/search-element.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/svg.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tables01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/template.dat (100%)
 create mode 100644 tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/template.js
 create mode 100644 tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/test.js
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests1.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests10.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests11.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests12.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests14.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests15.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests16.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests17.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests18.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests19.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests2.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests20.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests21.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests22.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests23.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests24.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests25.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests26.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests3.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests4.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests5.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests6.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests7.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests8.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests9.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tests_innerHTML_1.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/tricky01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/void-in-phrasing.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/webkit01.dat (100%)
 rename tests/phpunit/data/web-platform-tests/{tree-construction => html_syntax_parsing_resources}/webkit02.dat (100%)

diff --git a/tests/phpunit/data/web-platform-tests/AUTHORS.rst b/tests/phpunit/data/web-platform-tests/AUTHORS.rst
deleted file mode 100644
index 293d7fde18831..0000000000000
--- a/tests/phpunit/data/web-platform-tests/AUTHORS.rst
+++ /dev/null
@@ -1,34 +0,0 @@
-Credits
-=======
-
-The ``html5lib`` test data was originally maintained by:
-
-- James Graham
-- Geoffrey Sneddon
-
-
-Contributors
-------------
-
-- Adam Barth
-- Andi Sidwell
-- Anne van Kesteren
-- David Flanagan
-- Edward Z. Yang
-- Geoffrey Sneddon
-- Henri Sivonen
-- Ian Hickson
-- Jacques Distler
-- James Graham
-- Lachlan Hunt
-- lantis63
-- Mark Pilgrim
-- Mats Palmgren
-- Ms2ger
-- Nolan Waite
-- Philip Taylor
-- Rafael Weinstein
-- Ryan King
-- Sam Ruby
-- Simon Pieters
-- Thomas Broyer
diff --git a/tests/phpunit/data/web-platform-tests/LICENSE b/tests/phpunit/data/web-platform-tests/LICENSE
deleted file mode 100644
index 8812371b41cfc..0000000000000
--- a/tests/phpunit/data/web-platform-tests/LICENSE
+++ /dev/null
@@ -1,21 +0,0 @@
-Copyright (c) 2006-2013 James Graham, Geoffrey Sneddon, and
-other contributors
-
-Permission is hereby granted, free of charge, to any person obtaining
-a copy of this software and associated documentation files (the
-"Software"), to deal in the Software without restriction, including
-without limitation the rights to use, copy, modify, merge, publish,
-distribute, sublicense, and/or sell copies of the Software, and to
-permit persons to whom the Software is furnished to do so, subject to
-the following conditions:
-
-The above copyright notice and this permission notice shall be
-included in all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
-LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
-OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/tests/phpunit/data/web-platform-tests/LICENSE.md b/tests/phpunit/data/web-platform-tests/LICENSE.md
new file mode 100644
index 0000000000000..39c46d03ac298
--- /dev/null
+++ b/tests/phpunit/data/web-platform-tests/LICENSE.md
@@ -0,0 +1,11 @@
+# The 3-Clause BSD License
+
+Copyright © web-platform-tests contributors
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/tests/phpunit/data/web-platform-tests/README.md b/tests/phpunit/data/web-platform-tests/README.md
index 874ae275b2dfd..a111e20b48831 100644
--- a/tests/phpunit/data/web-platform-tests/README.md
+++ b/tests/phpunit/data/web-platform-tests/README.md
@@ -2,22 +2,12 @@
 
 This directory contains a third-party test suite used for testing the WordPress HTML API.
 
-The tree-construction tests are maintained by the Web Platform Tests project.
-The raw `.dat` fixtures can be found on GitHub at
-[web-platform-tests/wpt/html/syntax/parsing/resources](https://github.com/web-platform-tests/wpt/tree/master/html/syntax/parsing/resources).
+The tests are maintained by the Web Platform Tests project.
+The current tests can be found on GitHub at
+[`web-platform-tests/wpt/html/syntax/parsing/resources`](https://github.com/web-platform-tests/wpt/tree/master/html/syntax/parsing/resources).
 
-The necessary files have been copied to this directory:
-
-- `AUTHORS.rst`
-- `LICENSE`
-- `tree-construction/README.md`
-- `tree-construction/*.dat`
-
-The version of the WPT-copied files was taken from the git commit with
-SHA [`c469a8a72a2ce58c04601255a45504ab9f5cc763`](https://github.com/web-platform-tests/wpt/commit/c469a8a72a2ce58c04601255a45504ab9f5cc763).
-
-The `AUTHORS.rst` and `LICENSE` files document the original html5lib test suite
-attribution and license.
+The version of the WPT files was taken from the git commit with
+SHA [`1ae157bacf6cb1db64a60875800a30c80a4fc93c`](https://github.com/web-platform-tests/wpt/tree/1ae157bacf6cb1db64a60875800a30c80a4fc93c/html/syntax/parsing/resources).
 
 ## Updating
 
@@ -25,5 +15,5 @@ If there have been changes to the Web Platform Tests repository, this test suite
 order to update:
 
 1. Check out the latest version of git repository mentioned above.
-1. Copy `README.md` and `*.dat` from `html/syntax/parsing/resources/` into `tree-construction/`.
+1. Replace the local `html_syntax_parsing_resources/` directory with the WPT repo's `html/syntax/parsing/resources` directory.
 1. Update the SHA mentioned in this README file with the new Web Platform Tests SHA.
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/README.md b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/README.md
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/README.md
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/README.md
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/adoption01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/adoption01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/adoption01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/adoption01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/adoption02.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/adoption02.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/adoption02.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/adoption02.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/blocks.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/blocks.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/blocks.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/blocks.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/comments01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/comments01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/comments01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/comments01.dat
diff --git a/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/common.js b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/common.js
new file mode 100644
index 0000000000000..b3ac9ece70c43
--- /dev/null
+++ b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/common.js
@@ -0,0 +1,24 @@
+function mark_diffs(expected, actual) {
+  var expected_lines = expected.split("\n");
+  var actual_lines = actual.split("\n");
+
+  var max_length = Math.max(expected_lines.length, actual_lines.length);
+
+  var expected_diff = ["code", {}];
+  var actual_diff = ["code", {}];
+
+  for (var i=0; i<max_length; i++) {
+    if (expected_lines[i] === actual_lines[i]) {
+      expected_diff.push(expected_lines[i] + "\n");
+      actual_diff.push(actual_lines[i] + "\n");
+    } else {
+      if (expected_lines[i]) {
+        expected_diff.push(["span", {style:"color:red"}, expected_lines[i] + "\n"]);
+      }
+      if (actual_lines[i]) {
+        actual_diff.push(["span", {style:"color:red"}, actual_lines[i] + "\n"]);
+      }
+    }
+  }
+  return [expected_diff, actual_diff];
+}
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/doctype01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/doctype01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/doctype01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/doctype01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/domjs-unsafe.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/domjs-unsafe.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/domjs-unsafe.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/domjs-unsafe.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/entities01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/entities01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/entities01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/entities01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/entities02.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/entities02.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/entities02.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/entities02.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/foreign-fragment.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/foreign-fragment.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/foreign-fragment.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/foreign-fragment.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/html5test-com.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/html5test-com.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/html5test-com.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/html5test-com.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/inbody01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/inbody01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/inbody01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/inbody01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/isindex.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/isindex.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/isindex.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/isindex.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/main-element.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/main-element.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/main-element.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/main-element.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/math.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/math.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/math.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/math.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/menuitem-element.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/menuitem-element.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/menuitem-element.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/menuitem-element.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/namespace-sensitivity.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/namespace-sensitivity.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/namespace-sensitivity.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/namespace-sensitivity.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/noscript01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/noscript01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/noscript01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/noscript01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/pending-spec-changes-plain-text-unsafe.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/pending-spec-changes-plain-text-unsafe.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/pending-spec-changes-plain-text-unsafe.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/pending-spec-changes-plain-text-unsafe.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/pending-spec-changes.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/pending-spec-changes.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/pending-spec-changes.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/pending-spec-changes.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/plain-text-unsafe.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/plain-text-unsafe.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/plain-text-unsafe.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/plain-text-unsafe.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/processing-instructions.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/processing-instructions.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/processing-instructions.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/processing-instructions.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/quirks01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/quirks01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/quirks01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/quirks01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/ruby.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/ruby.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/ruby.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/ruby.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/scriptdata01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/scriptdata01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/scriptdata01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/scriptdata01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/scripted_adoption01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/scripted_adoption01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/scripted_adoption01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/scripted_adoption01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/scripted_ark.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/scripted_ark.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/scripted_ark.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/scripted_ark.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/scripted_webkit01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/scripted_webkit01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/scripted_webkit01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/scripted_webkit01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/search-element.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/search-element.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/search-element.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/search-element.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/svg.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/svg.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/svg.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/svg.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tables01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tables01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tables01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tables01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/template.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/template.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/template.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/template.dat
diff --git a/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/template.js b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/template.js
new file mode 100644
index 0000000000000..b249fb64c71c1
--- /dev/null
+++ b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/template.js
@@ -0,0 +1,214 @@
+    /*
+     * Template code
+     *
+     * A template is just a javascript structure. An element is represented as:
+     *
+     * [tag_name, {attr_name:attr_value}, child1, child2]
+     *
+     * the children can either be strings (which act like text nodes), other templates or
+     * functions (see below)
+     *
+     * A text node is represented as
+     *
+     * ["{text}", value]
+     *
+     * String values have a simple substitution syntax; ${foo} represents a variable foo.
+     *
+     * It is possible to embed logic in templates by using a function in a place where a
+     * node would usually go. The function must either return part of a template or null.
+     *
+     * In cases where a set of nodes are required as output rather than a single node
+     * with children it is possible to just use a list
+     * [node1, node2, node3]
+     *
+     * Usage:
+     *
+     * render(template, substitutions) - take a template and an object mapping
+     * variable names to parameters and return either a DOM node or a list of DOM nodes
+     *
+     * substitute(template, substitutions) - take a template and variable mapping object,
+     * make the variable substitutions and return the substituted template
+     *
+     */
+
+    function is_single_node(template)
+    {
+        return typeof template[0] === "string";
+    }
+
+    function substitute(template, substitutions)
+    {
+        if (typeof template === "function") {
+            var replacement = template(substitutions);
+            if (replacement)
+            {
+                var rv = substitute(replacement, substitutions);
+                return rv;
+            }
+            else
+            {
+                return null;
+            }
+        }
+        else if (is_single_node(template))
+        {
+            return substitute_single(template, substitutions);
+        }
+        else
+        {
+            return filter(map(template, function(x) {
+                                  return substitute(x, substitutions);
+                              }), function(x) {return x !== null;});
+        }
+    }
+    expose(substitute, "template.substitute");
+
+    function substitute_single(template, substitutions)
+    {
+        var substitution_re = /\${([^ }]*)}/g;
+
+        function do_substitution(input) {
+            var components = input.split(substitution_re);
+            var rv = [];
+            for (var i=0; i<components.length; i+=2)
+            {
+                rv.push(components[i]);
+                if (components[i+1])
+                {
+                    rv.push(substitutions[components[i+1]]);
+                }
+            }
+            return rv;
+        }
+
+        var rv = [];
+        rv.push(do_substitution(String(template[0])).join(""));
+
+        if (template[0] === "{text}") {
+            substitute_children(template.slice(1), rv);
+        } else {
+            substitute_attrs(template[1], rv);
+            substitute_children(template.slice(2), rv);
+        }
+
+        function substitute_attrs(attrs, rv)
+        {
+            rv[1] = {};
+            for (name in template[1])
+            {
+                if (attrs.hasOwnProperty(name))
+                {
+                    var new_name = do_substitution(name).join("");
+                    var new_value = do_substitution(attrs[name]).join("");
+                    rv[1][new_name] = new_value;
+                };
+            }
+        }
+
+        function substitute_children(children, rv)
+        {
+            for (var i=0; i<children.length; i++)
+            {
+                if (children[i] instanceof Object) {
+                    var replacement = substitute(children[i], substitutions);
+                    if (replacement !== null)
+                    {
+                        if (is_single_node(replacement))
+                        {
+                            rv.push(replacement);
+                        }
+                        else
+                        {
+                            extend(rv, replacement);
+                        }
+                    }
+                }
+                else
+                {
+                    extend(rv, do_substitution(String(children[i])));
+                }
+            }
+            return rv;
+        }
+
+        return rv;
+    }
+
+    function make_dom_single(template)
+    {
+        if (template[0] === "{text}")
+        {
+            var element = document.createTextNode("");
+            for (var i=1; i<template.length; i++)
+            {
+                element.data += template[i];
+            }
+        }
+        else
+        {
+            var element = document.createElement(template[0]);
+            for (name in template[1]) {
+                if (template[1].hasOwnProperty(name))
+                {
+                    element.setAttribute(name, template[1][name]);
+                }
+            }
+            for (var i=2; i<template.length; i++)
+            {
+                if (template[i] instanceof Object)
+                {
+                    var sub_element = make_dom(template[i]);
+                    element.appendChild(sub_element);
+                }
+                else
+                {
+                    var text_node = document.createTextNode(template[i]);
+                    element.appendChild(text_node);
+                }
+            }
+        }
+
+        return element;
+    }
+
+
+
+    function make_dom(template, substitutions)
+    {
+        if (is_single_node(template))
+        {
+            return make_dom_single(template);
+        }
+        else
+        {
+            return map(template, function(x) {
+                           return make_dom_single(x);
+                       });
+        }
+    }
+
+    function render(template, substitutions)
+    {
+        return make_dom(substitute(template, substitutions));
+    }
+    expose(render, "template.render");
+
+function expose(object, name)
+{
+  var components = name.split(".");
+  var target = window;
+  for (var i=0; i<components.length - 1; i++)
+  {
+    if (!(components[i] in target))
+    {
+      target[components[i]] = {};
+    }
+    target = target[components[i]];
+  }
+  target[components[components.length - 1]] = object;
+}
+
+function extend(array, items)
+{
+  Array.prototype.push.apply(array, items);
+}
\ No newline at end of file
diff --git a/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/test.js b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/test.js
new file mode 100644
index 0000000000000..f214cada7a1b3
--- /dev/null
+++ b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/test.js
@@ -0,0 +1,337 @@
+// Runner for html5lib-tests .dat files.
+//
+// Each wrapper page (html5lib_url.html, html5lib_write.html, …) loads this
+// script with `<script src="resources/test.js" data-run-type="…"></script>`
+// and lists each .dat file as `<meta name=variant content="?file=NAME">`.
+// We fetch resources/NAME.dat, parse it, and run each entry: document tests
+// parse via the page's run_type; entries with #document-fragment always parse
+// via innerHTML.
+
+(() => {
+  "use strict";
+
+  const NAMESPACES = {
+    html:   "http://www.w3.org/1999/xhtml",
+    math:   "http://www.w3.org/1998/Math/MathML",
+    mathml: "http://www.w3.org/1998/Math/MathML",
+    svg:    "http://www.w3.org/2000/svg",
+    xlink:  "http://www.w3.org/1999/xlink",
+    xml:    "http://www.w3.org/XML/1998/namespace",
+    xmlns:  "http://www.w3.org/2000/xmlns/",
+  };
+  const PREFIXES = {};
+  for (const prefix of Object.keys(NAMESPACES)) {
+    PREFIXES[NAMESPACES[prefix]] = prefix;
+  }
+  PREFIXES[NAMESPACES.mathml] = "math";
+
+  function serializeTree(root) {
+    root.normalize();
+    const lines = [];
+    // The .dat #document format prefixes each line with "|" + N spaces of
+    // indent, where the document itself has no "|" line, its direct children
+    // get 1 space, their children get 3, then 5, 7, … (i.e. 2*depth - 1).
+    const walk = (node, depth) => {
+      const pad = depth > 0 ? " ".repeat(2 * depth - 1) : "";
+      const innerPad = " ".repeat(2 * depth + 1);
+      switch (node.nodeType) {
+        case Node.DOCUMENT_TYPE_NODE:
+          if (node.name) {
+            if (node.publicId || node.systemId) {
+              lines.push(`|${pad}<!DOCTYPE ${node.name} "${node.publicId ?? ""}" "${node.systemId ?? ""}">`);
+            } else {
+              lines.push(`|${pad}<!DOCTYPE ${node.name}>`);
+            }
+          } else {
+            lines.push(`|${pad}<!DOCTYPE >`);
+          }
+          break;
+        case Node.DOCUMENT_NODE:
+          lines.push("#document");
+          break;
+        case Node.DOCUMENT_FRAGMENT_NODE:
+          lines.push("#document-fragment");
+          break;
+        case Node.COMMENT_NODE:
+          lines.push(`|${pad}<!-- ${node.nodeValue} -->`);
+          break;
+        case Node.PROCESSING_INSTRUCTION_NODE:
+          lines.push(`|${pad}<?${node.target}${node.data ? " " + node.data : ""}?>`);
+          break;
+        case Node.TEXT_NODE:
+          lines.push(`|${pad}"${node.nodeValue}"`);
+          break;
+        case Node.ELEMENT_NODE: {
+          if (node.getAttribute("data-skip") !== null) return;
+          const tag = (node.namespaceURI && node.namespaceURI !== NAMESPACES.html)
+            ? `${PREFIXES[node.namespaceURI]} ${node.localName}`
+            : node.localName;
+          lines.push(`|${pad}<${tag}>`);
+          const attrs = [...node.attributes].map(a => [
+            (a.namespaceURI ? PREFIXES[a.namespaceURI] + " " : "") + a.localName,
+            a.value,
+          ]);
+          attrs.sort((a, b) => a[0] === b[0] ? 0 : (a[0] > b[0] ? 1 : -1));
+          for (const [name, value] of attrs) {
+            lines.push(`|${innerPad}${name}="${value}"`);
+          }
+          if (node.namespaceURI === NAMESPACES.html && node.localName === "template") {
+            lines.push(`|${innerPad}content`);
+            for (const child of node.content.childNodes) walk(child, depth + 2);
+          }
+          break;
+        }
+      }
+      for (const child of node.childNodes) walk(child, depth + 1);
+    };
+    walk(root, 0);
+    return lines.join("\n");
+  }
+
+  // Per-flavor runners. Each fills `iframe` with the parser's output, then
+  // serializes and asserts. record() captures input/expected/actual on the
+  // shared map so failure diffs can be rendered after the run.
+  function makeDocRunner(inject) {
+    return ({ iframe, t, id, input, expected, record }) => {
+      record({ id, input, expected, actual: null });
+      iframe.onload = () => t.step(() => {
+        iframe.onload = null;
+        const actual = serializeTree(iframe.contentDocument);
+        record({ id, input, expected, actual });
+        assert_equals(actual, expected);
+        t.done();
+      });
+      inject(iframe, input, t);
+    };
+  }
+
+  const RUNNERS = {
+    url: makeDocRunner((iframe, input, t) => {
+      const blob = new Blob([input], { type: "text/html" });
+      const url = URL.createObjectURL(blob);
+      iframe.src = url;
+      t.add_cleanup(() => URL.revokeObjectURL(url));
+    }),
+    write: makeDocRunner((iframe, input) => {
+      iframe.contentDocument.open();
+      iframe.contentDocument.write(input);
+      iframe.contentDocument.close();
+    }),
+    write_single: makeDocRunner((iframe, input) => {
+      iframe.contentDocument.open();
+      for (const ch of input) iframe.contentDocument.write(ch);
+      iframe.contentDocument.close();
+    }),
+    innerHTML: ({ iframe, t, id, input, expected, container, record }) => {
+      const parts = container.split(" ");
+      const containerEl = parts.length > 1
+        ? document.createElementNS(NAMESPACES[parts[0]], `${parts[0]}:${parts[1]}`)
+        : document.createElement(container);
+      containerEl.innerHTML = input;
+      const root = (containerEl.namespaceURI === NAMESPACES.html && containerEl.localName === "template")
+        ? containerEl.content : containerEl;
+      let actual = serializeTree(root);
+      record({ id, input, expected, actual, container });
+      // serializeTree emits "#document-fragment"; the .dat expected tree uses
+      // "#document" as its root marker.
+      const lines = actual.split("\n");
+      assert_not_equals(lines[0], "<template>", "template is never the innerHTML context object");
+      lines[0] = "#document";
+      actual = lines.join("\n");
+      assert_equals(actual, expected);
+      t.done();
+    },
+  };
+
+  // .dat format (html5lib-tests):
+  //   #data            input HTML
+  //   #errors / #new-errors / #errors-new  parsing errors (ignored here)
+  //   #script-on / #script-off            scripting requirement (we honor #script-off)
+  //   #document-fragment NAME             context element for innerHTML
+  //   #document                           expected serialized tree
+  // This mirrors the upstream html5lib-python TestData parser:
+  // each section accumulates raw lines (with trailing \n), and at every test
+  // boundary the active section gets one extra char clipped (the blank-line
+  // separator) before the per-section trailing-\n normalization runs.
+  function parseDat(text) {
+    if (text.endsWith("\n")) text = text.slice(0, -1);
+    const fileLines = text.split("\n");
+    const cases = [];
+    let data = null;
+    let key = null;
+
+    const isSectionHeading = line => {
+      if (!line.startsWith("#")) return null;
+      const heading = line.slice(1).trim();
+      return heading || null;
+    };
+    const normalise = obj => {
+      const out = {};
+      for (const k of Object.keys(obj)) {
+        out[k] = obj[k].endsWith("\n") ? obj[k].slice(0, -1) : obj[k];
+      }
+      return out;
+    };
+
+    for (let i = 0; i < fileLines.length; i++) {
+      const line = fileLines[i] + (i === fileLines.length - 1 ? "" : "\n");
+      const heading = isSectionHeading(line);
+      if (heading) {
+        if (data && heading === "data") {
+          if (key !== null && data[key].length > 0) {
+            data[key] = data[key].slice(0, -1);
+          }
+          cases.push(normalise(data));
+          data = null;
+        }
+        if (data === null) data = {};
+        key = heading;
+        data[key] = "";
+      } else if (key !== null) {
+        data[key] += line;
+      }
+    }
+    if (data) cases.push(normalise(data));
+
+    return cases.map(c => ({
+      data: c["data"] ?? "",
+      document: c["document"] ?? "",
+      fragment: c["document-fragment"],
+      scriptOff: "script-off" in c,
+    }));
+  }
+
+  function printDiff({ id, input, expected, actual, container }) {
+    const [expectedText, actualText] = actual
+      ? mark_diffs(expected, actual)
+      : [expected, ""];
+    const tmpl = ["div", { id: "${id}" },
+      ["h2", {}, "${id}"],
+      vars => vars.container != null
+        ? ["div", { class: "container" },
+            ["h3", {}, "innerHTML Container"],
+            ["pre", {}, vars.container]]
+        : null,
+      ["div", { id: "input_${id}" }, ["h3", {}, "Input"],
+        ["pre", {}, ["code", {}, input]]],
+      ["div", { id: "expected_${id}" }, ["h3", {}, "Expected"],
+        ["pre", {}, ["code", {}, expectedText]]],
+      ["div", { id: "actual_${id}" }, ["h3", {}, "Actual"],
+        ["pre", {}, ["code", {}, actualText]]],
+    ];
+    document.body.appendChild(template.render(tmpl, { id, container: container ?? null }));
+  }
+
+  // ----- Entry point -----
+
+  const NUM_IFRAMES = 8;
+  const runType = document.currentScript.dataset.runType;
+  const file = new URLSearchParams(location.search).get("file");
+
+  setup({ explicit_done: true });
+
+  if (!file || !RUNNERS[runType]) {
+    test(() => assert_unreached(`bad config: file=${file}, runType=${runType}`),
+         "html5lib-runner setup");
+    done();
+    return;
+  }
+
+  fetch(`resources/${file}.dat`)
+    .then(r => r.ok ? r.text() : Promise.reject(new Error(`fetch ${file}.dat: ${r.status}`)))
+    .then(text => {
+      const cases = parseDat(text).filter(c => !c.scriptOff);
+      const entries = [];
+      const seenNames = new Set();
+      const records = new Map();          // iframe.id -> latest record for that test
+      const iframeForTest = new Map();    // test.name -> iframe.id
+
+      const escapeForName = s => s.replace(/[\x00-\x1f]/g, ch => {
+        const code = ch.charCodeAt(0);
+        if (code === 0x0a) return "\\n";
+        if (code === 0x0d) return "\\r";
+        if (code === 0x09) return "\\t";
+        return `\\x${code.toString(16).padStart(2, "0")}`;
+      });
+
+      for (const c of cases) {
+        // Fragment tests don't depend on the page's parsing mode (they always
+        // go through innerHTML), so we run them in only one wrapper to avoid
+        // counting the same assertion three times.
+        if (c.fragment !== undefined && runType !== "url") continue;
+        const name = c.fragment !== undefined
+          ? `${escapeForName(c.data)} (innerHTML in ${c.fragment})`
+          : escapeForName(c.data);
+        // Identical (input, fragment-context) pairs would collide as test
+        // names. Upstream html5lib-tests doesn't ship any (after #script-off
+        // is filtered out); if that ever changes we want to know rather than
+        // silently drop one.
+        if (seenNames.has(name)) {
+          throw new Error(`duplicate test in ${file}.dat: ${name}`);
+        }
+        seenNames.add(name);
+        entries.push({
+          t: async_test(name),
+          input: c.data,
+          expected: "#document\n" + c.document,
+          fragment: c.fragment,
+        });
+      }
+
+      // Nothing to run (e.g. fragment-only .dat in a non-url wrapper). The
+      // updater shouldn't list such variants; surface a clear failure if one
+      // ever does end up here so the cause is obvious.
+      if (entries.length === 0) {
+        throw new Error(`${file}.dat has no tests for run_type=${runType}`);
+      }
+
+      const fails = [];
+      let started = 0;
+      let completed = 0;
+
+      add_result_callback(testObj => {
+        completed++;
+        let iframe = document.getElementById(iframeForTest.get(testObj.name));
+        if (testObj.status !== testObj.PASS) {
+          fails.push(records.get(iframe.id));
+          const fresh = document.createElement("iframe");
+          fresh.style.display = "none";
+          fresh.id = iframe.id;
+          document.body.replaceChild(fresh, iframe);
+          iframe = fresh;
+        }
+        if (completed === entries.length) {
+          done();
+        } else if (started < entries.length) {
+          runNext(iframe);
+        }
+      });
+
+      add_completion_callback(() => fails.forEach(printDiff));
+
+      for (let i = 0; i < NUM_IFRAMES; i++) {
+        const iframe = document.createElement("iframe");
+        iframe.id = `iframe_${i}`;
+        iframe.style.display = "none";
+        document.body.appendChild(iframe);
+      }
+
+      const runNext = iframe => {
+        const entry = entries[started++];
+        const runner = entry.fragment !== undefined ? RUNNERS.innerHTML : RUNNERS[runType];
+        iframeForTest.set(entry.t.name, iframe.id);
+        const record = data => records.set(iframe.id, data);
+        step_timeout(() => entry.t.step(() => {
+          runner({ iframe, t: entry.t, id: entry.t.name, input: entry.input, expected: entry.expected, container: entry.fragment, record });
+        }), 0);
+      };
+
+      for (const iframe of document.getElementsByTagName("iframe")) {
+        if (started < entries.length) runNext(iframe);
+      }
+    })
+    .catch(err => {
+      test(() => { throw err; }, `html5lib-runner: load ${file}.dat`);
+      done();
+    });
+})();
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests1.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests1.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests1.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests1.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests10.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests10.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests10.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests10.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests11.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests11.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests11.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests11.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests12.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests12.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests12.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests12.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests14.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests14.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests14.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests14.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests15.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests15.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests15.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests15.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests16.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests16.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests16.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests16.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests17.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests17.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests17.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests17.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests18.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests18.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests18.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests18.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests19.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests19.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests19.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests19.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests2.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests2.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests2.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests2.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests20.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests20.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests20.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests20.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests21.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests21.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests21.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests21.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests22.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests22.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests22.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests22.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests23.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests23.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests23.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests23.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests24.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests24.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests24.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests24.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests25.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests25.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests25.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests25.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests26.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests26.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests26.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests26.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests3.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests3.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests3.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests3.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests4.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests4.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests4.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests4.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests5.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests5.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests5.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests5.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests6.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests6.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests6.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests6.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests7.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests7.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests7.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests7.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests8.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests8.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests8.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests8.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests9.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests9.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests9.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests9.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tests_innerHTML_1.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests_innerHTML_1.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tests_innerHTML_1.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tests_innerHTML_1.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/tricky01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tricky01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/tricky01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/tricky01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/void-in-phrasing.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/void-in-phrasing.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/void-in-phrasing.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/void-in-phrasing.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/webkit01.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/webkit01.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/webkit01.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/webkit01.dat
diff --git a/tests/phpunit/data/web-platform-tests/tree-construction/webkit02.dat b/tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/webkit02.dat
similarity index 100%
rename from tests/phpunit/data/web-platform-tests/tree-construction/webkit02.dat
rename to tests/phpunit/data/web-platform-tests/html_syntax_parsing_resources/webkit02.dat

From 0faa10058989d6d0395329887bfcffa1a0e5feae Mon Sep 17 00:00:00 2001
From: Jon Surrell <sirreal@users.noreply.github.com>
Date: Fri, 3 Jul 2026 20:14:32 +0200
Subject: [PATCH 5/5] Update WPT dir

---
 .../tests/html-api/wpHtmlProcessorWebPlatformTests.php        | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/phpunit/tests/html-api/wpHtmlProcessorWebPlatformTests.php b/tests/phpunit/tests/html-api/wpHtmlProcessorWebPlatformTests.php
index 633477d2dac0f..16d3e49173009 100644
--- a/tests/phpunit/tests/html-api/wpHtmlProcessorWebPlatformTests.php
+++ b/tests/phpunit/tests/html-api/wpHtmlProcessorWebPlatformTests.php
@@ -10,7 +10,7 @@
  * fixtures are used by other projects like browsers or other HTML parsers for the same purpose
  * of validating behavior against an external reference.
  *
- * See the README file at DIR_TESTDATA / web-platform-tests for details on the third-party suite.
+ * See the README file at `DIR_TESTDATA . "/web-platform-tests"` for details on the third-party suite.
  *
  * @package WordPress
  * @subpackage HTML-API
@@ -132,7 +132,7 @@ public function test_parse( ?string $fragment_context, string $html, string $exp
 	 * @return array[]
 	 */
 	public function data_external_web_platform_tests() {
-		$test_dir = DIR_TESTDATA . '/web-platform-tests/tree-construction/';
+		$test_dir = DIR_TESTDATA . '/web-platform-tests/html_syntax_parsing_resources/';
 
 		$handle = opendir( $test_dir );
 		while ( false !== ( $entry = readdir( $handle ) ) ) {