Fix style offsets

Author: robotdana

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.4, 2.5, 2.6, 2.7, ruby-3.0.0-preview1, ruby-head, jruby, jruby-head]
+        ruby: [2.4, 2.5, 2.6, 2.7, '3.0', 3.1, 3.2, 3.3, 3.4, ruby-head, jruby, jruby-head]
     continue-on-error: ${{ endsWith(matrix.ruby, 'head') }}
     runs-on: ubuntu-latest
     steps:
@@ -47,7 +47,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 2.7
+        ruby-version: 3.4
         bundler-cache: true
     - run: bundle exec rubocop
 
@@ -67,7 +67,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 2.7
+        ruby-version: 3.4
         bundler-cache: true
     - run: bundle exec leftovers
 
@@ -77,6 +77,6 @@ jobs:
     - uses: actions/checkout@v2
     - uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 2.7
+        ruby-version: 3.4
         bundler-cache: true
     - run: bundle exec rake build

.gitignore

@@ -3,3 +3,4 @@
 /pkg/
 /.rspec_status
 /Gemfile.lock
+/.ruby-version

.spellr_wordlists/english.txt

@@ -2,6 +2,7 @@ ansi
 arity
 changelog
 cli
+csi
 gemfile
 i'll
 jruby
@@ -23,3 +24,4 @@ sudo
 tmp
 truffleruby
 tty
+unstyled

.spellr_wordlists/ruby.txt

@@ -1,4 +1,5 @@
 cov
+cyclomatic
 rspec
 rubo
 rubocop

CHANGELOG.md

@@ -1,3 +1,12 @@
+# v2.0.0
+- TTYString is now a module not a class.
+- Address the issue where preserved styles and unknown codes would cause the cursor to be misaligned when moving, and potentially overwriting styles unexpectedly:
+  - `clear_style: false` is now `style: TTYString::RENDER`, which modifies styles to display as they would rather than just passing them through them unprocessed
+  - `clear_style: true` is now `style: TTYString::DROP` (and still the default)
+  - Unknown codes are now dropped by default
+  - it's now possible to set `unknown: TTYString::RAISE` to raise on unrecognized CSI codes (`unknown: TTYString::DROP` is the default)
+- drop more codes that are known to do nothing for the display of text `\e[?5l`,`\e[?5h`,`\e[?25l`,`\e[?25h`,`\e[?1004l`,`\e[?1004h`,`\e[?1049l`,`\e[?1049h`
+
 # v1.1.1
 - i forgot how arity works
 

README.md

@@ -32,11 +32,20 @@ Intended for use in tests of command line interfaces.
 | `\e[nK` | _n_=`0`: clear the line from the cursor forward <br>_n_=`1`: clear the line from the cursor backward <br>_n_=`2`: clear the line | _n_=`0` |
 | `\e[nS` | scroll up _n_ rows | _n_=`1` |
 | `\e[nT` | scroll down _n_ rows | _n_=`1` |
-| `\e[m` | styling codes: optionally suppressed with `clear_style: false` | |
-| `\e[?2004h` | enabled bracketed paste: suppressed | |
-| `\e[?2004l` | disable bracketed paste: suppressed | |
-| `\e[200~` | bracketed paste start: suppressed | |
-| `\e[201~` | bracketed paste end: suppressed | |
+| `\e[m` | styling codes: dropped with `style: :drop` (default), rendered with `style: :render`. | |
+| `\e[?5h` | reverse the screen: dropped | |
+| `\e[?5l` | normal the screen: dropped | |
+| `\e[?25h` | show the cursor: dropped | |
+| `\e[?25l` | hide the cursor: dropped | |
+| `\e[?1004h` | enable reporting focus: dropped | |
+| `\e[?1004l` | disable reporting focus: dropped | |
+| `\e[?1049h` | enable alternate screen buffer: dropped | |
+| `\e[?1049l` | disable alternate screen buffer: dropped | |
+| `\e[?2004h` | enable bracketed paste mode: dropped | |
+| `\e[?2004l` | disable bracketed paste mode: dropped | |
+| `\e[200~` | bracketed paste start: dropped | |
+| `\e[201~` | bracketed paste end: dropped | |
+| `\e[` | any other valid CSI code: dropped with `unknown: :drop` (default), raises TTYString::Error with `unknown: :raise`. | |
 
 ## Installation
 
@@ -61,14 +70,19 @@ TTYString.parse("th\ta string\e[3Gis is")
 => "this is a string"
 ```
 
-Styling information is suppressed by default:
+Styling information is dropped by default:
 ```ruby
 TTYString.parse("th\ta \e[31mstring\e[0m\e[3Gis is")
 => "this is a string"
 ```
-But can be passed through:
+But can be rendered:
 ```ruby
-TTYString.parse("th\ta \e[31mstring\e[0m\e[3Gis is", clear_style: false)
+TTYString.parse("th\ta \e[31mstring\e[0m\e[3Gis is", style: :render)
+=> "this is a \e[31mstring\e[0m"
+```
+
+```ruby
+TTYString.parse("th\ta \e[31mstring\e[0m\e[3Gis is", style: :render)
 => "this is a \e[31mstring\e[0m"
 ```
 
@@ -81,10 +95,7 @@ Just for fun TTYString.to_proc provides the `parse` method as a lambda, so:
 ## Limitations
 
 - Various terminals are wildly variously permissive with what they accept,
-  so this doesn't even try to cover all possible cases,
-  instead it covers the narrowest possible case, and leaves the codes in place when unrecognized
-
-- `clear_style: false` treats the style codes as regular text which may work differently when rendering codes that move the cursor.
+  so this doesn't even try to cover all possible cases
 
 ## Development
 

lib/tty_string.rb

@@ -4,27 +4,33 @@
 
 # Renders a string taking into ANSI escape codes and \t\r\n etc
 # Usage: TTYString.parse("This\r\e[KThat") => "That"
-class TTYString
+module TTYString
+  class Error < StandardError; end
+  class UnknownCodeError < Error; end
+
+  RENDER = :render
+  RAISE = :raise
+  DROP = :drop
+
+  UNKNOWN_OPTIONS = [RAISE, DROP].freeze
+  private_constant :UNKNOWN_OPTIONS
+  STYLE_OPTIONS = [RENDER, DROP].freeze
+  private_constant :STYLE_OPTIONS
+
   class << self
-    def parse(input_string, clear_style: true)
-      new(input_string, clear_style: clear_style).to_s
+    def parse(input_string, style: DROP, unknown: DROP) # rubocop:disable Metrics/MethodLength
+      unless STYLE_OPTIONS.include?(style)
+        raise ArgumentError, '`style:` must be either TTYString::RENDER or TTYString::DROP (default)'
+      end
+      unless UNKNOWN_OPTIONS.include?(unknown)
+        raise ArgumentError, '`unknown:` must be either TTYString::RAISE or TTYString::DROP (default)'
+      end
+
+      Parser.new(input_string).render(style: style, unknown: unknown)
     end
 
     def to_proc
       method(:parse).to_proc
     end
   end
-
-  def initialize(input_string, clear_style: true)
-    @parser = Parser.new(input_string)
-    @parser.clear_style = clear_style
-  end
-
-  def to_s
-    parser.render
-  end
-
-  private
-
-  attr_reader :clear_style, :parser
 end

lib/tty_string/cell.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module TTYString
+  class Cell
+    attr_reader :style, :value
+
+    def initialize(value, style: NullStyle)
+      @style = style
+      @value = value
+    end
+
+    def to_s(style_context: NullStyle)
+      "#{style.to_s(context: style_context)}#{value}"
+    end
+  end
+end

lib/tty_string/code.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class TTYString
+module TTYString
   class Code
     class << self
       def descendants

lib/tty_string/code_definitions.rb

@@ -3,7 +3,7 @@
 require_relative 'code'
 require_relative 'csi_code'
 
-class TTYString
+module TTYString
   class Code
     class SlashA < TTYString::Code # leftovers:allow
       char "\a"
@@ -32,7 +32,7 @@ class SlashN < TTYString::Code # leftovers:allow
       def action
         cursor.down
         cursor.col = 0
-        screen.write('')
+        screen.ensure_row
       end
     end