fix(no-heading-like-lines): do not flag numbered-list bold/italic when content ends with sentence punctuation

Skip reporting for lines like "3. **This should not be flagged.**" so
bolded list items that are full sentences are not treated as heading-like.

Author: cypher0n3

markdownlint-rules/no-heading-like-lines.js

@@ -56,6 +56,9 @@ const EXTRACTORS = [
 /** Pattern indices that are MD036-style (whole-line emphasis); skip when content ends with punctuation. */
 const MD036_STYLE_PATTERN_INDICES = new Set([6, 7]);
 
+/** Pattern indices for numbered-list bold/italic; skip when content ends with sentence punctuation (e.g. "1. **Sentence.**"). */
+const NUMBERED_LIST_EMPHASIS_PATTERN_INDICES = new Set([2, 5]);
+
 /**
  * Extract plain title from a heading-like line given the pattern index that matched.
  * @param {string} trimmedLine - Trimmed line content
@@ -144,6 +147,10 @@ function findHeadingLikeMatch(trimmedLine, punctuationMarks) {
       const lastChar = extractedTitle.slice(-1);
       if (punctuationMarks.includes(lastChar)) continue;
     }
+    if (NUMBERED_LIST_EMPHASIS_PATTERN_INDICES.has(p) && extractedTitle.length > 0) {
+      const lastChar = extractedTitle.slice(-1);
+      if (punctuationMarks.includes(lastChar)) return null;
+    }
     return { p, description, extractedTitle };
   }
   return null;

md_test_files/expected_errors.yml

@@ -129,14 +129,14 @@ negative_heading_like.md:
     - line: 14
       rule: no-heading-like-lines
       message_contains: numbered list with bold
-    - line: 16
+    - line: 18
       rule: MD036/no-emphasis-as-heading
-    - line: 16
+    - line: 18
       rule: no-heading-like-lines
       message_contains: bold only
-    - line: 18
+    - line: 20
       rule: MD036/no-emphasis-as-heading
-    - line: 18
+    - line: 20
       rule: no-heading-like-lines
       message_contains: italic only
 

md_test_files/negative_heading_like.md

@@ -13,6 +13,8 @@
 
 1. **Numbered list with bold only**
 
+2. **This should not be flagged.**
+
 **Introduction**
 
 *Note*

test/markdownlint-rules/no-heading-like-lines.test.js

@@ -48,6 +48,12 @@ describe("no-heading-like-lines", () => {
     assert.ok(errors[0].detail.includes("numbered") || errors[0].detail.includes("bold"), "detail should describe the matched pattern");
   });
 
+  it("does not report numbered list when bold content ends with sentence punctuation", () => {
+    const lines = ["3. **This should not be flagged.**", "Content."];
+    const errors = runRule(rule, lines);
+    assert.strictEqual(errors.length, 0, "1. **Sentence.** should not be flagged as heading-like");
+  });
+
   it("reports error for MD036-style **Introduction** (whole line bold)", () => {
     const lines = ["**Introduction**", "Content here."];
     const errors = runRule(rule, lines);