Reimplement MD025/single-title/single-h1 using micromark tokens.

demo/markdownlint-browser.js

@@ -4671,8 +4671,9 @@ module.exports = {
 
 
 
-const { addErrorContext, filterTokens, frontMatterHasTitle } =
-  __webpack_require__(/*! ../helpers */ "../helpers/helpers.js");
+const { addErrorContext, frontMatterHasTitle } = __webpack_require__(/*! ../helpers */ "../helpers/helpers.js");
+const { filterByTypes, getHeadingLevel, inHtmlFlow } =
+  __webpack_require__(/*! ../helpers/micromark.cjs */ "../helpers/micromark.cjs");
 
 // eslint-disable-next-line jsdoc/valid-types
 /** @type import("./markdownlint").Rule */
@@ -4680,26 +4681,41 @@ module.exports = {
   "names": [ "MD025", "single-title", "single-h1" ],
   "description": "Multiple top-level headings in the same document",
   "tags": [ "headings" ],
-  "parser": "markdownit",
+  "parser": "micromark",
   "function": function MD025(params, onError) {
     const level = Number(params.config.level || 1);
-    const tag = "h" + level;
     const foundFrontMatterTitle =
       frontMatterHasTitle(
         params.frontMatterLines,
         params.config.front_matter_title
       );
     let hasTopLevelHeading = false;
-    filterTokens(params, "heading_open", function forToken(token) {
-      if (token.tag === tag) {
+    const headings = filterByTypes(
+      params.parsers.micromark.tokens,
+      [ "atxHeading", "setextHeading" ]
+    );
+    for (const heading of headings) {
+      const headingLevel = getHeadingLevel(heading);
+      if ((headingLevel === level) && !inHtmlFlow(heading)) {
         if (hasTopLevelHeading || foundFrontMatterTitle) {
-          addErrorContext(onError, token.lineNumber,
-            token.line.trim());
-        } else if (token.lineNumber === 1) {
+          const headingTexts = filterByTypes(
+            heading.children,
+            [ "atxHeadingText", "setextHeadingText" ]
+          );
+          const headingText = headingTexts.
+            map((token) => token.text).
+            join(" ").
+            replace(/[\r\n]+/g, " ");
+          addErrorContext(
+            onError,
+            heading.startLine,
+            headingText
+          );
+        } else if (heading.startLine === 1) {
           hasTopLevelHeading = true;
         }
       }
-    });
+    }
   }
 };
 

lib/md025.js

@@ -2,8 +2,9 @@
 
 "use strict";
 
-const { addErrorContext, filterTokens, frontMatterHasTitle } =
-  require("../helpers");
+const { addErrorContext, frontMatterHasTitle } = require("../helpers");
+const { filterByTypes, getHeadingLevel, inHtmlFlow } =
+  require("../helpers/micromark.cjs");
 
 // eslint-disable-next-line jsdoc/valid-types
 /** @type import("./markdownlint").Rule */
@@ -11,25 +12,40 @@ module.exports = {
   "names": [ "MD025", "single-title", "single-h1" ],
   "description": "Multiple top-level headings in the same document",
   "tags": [ "headings" ],
-  "parser": "markdownit",
+  "parser": "micromark",
   "function": function MD025(params, onError) {
     const level = Number(params.config.level || 1);
-    const tag = "h" + level;
     const foundFrontMatterTitle =
       frontMatterHasTitle(
         params.frontMatterLines,
         params.config.front_matter_title
       );
     let hasTopLevelHeading = false;
-    filterTokens(params, "heading_open", function forToken(token) {
-      if (token.tag === tag) {
+    const headings = filterByTypes(
+      params.parsers.micromark.tokens,
+      [ "atxHeading", "setextHeading" ]
+    );
+    for (const heading of headings) {
+      const headingLevel = getHeadingLevel(heading);
+      if ((headingLevel === level) && !inHtmlFlow(heading)) {
         if (hasTopLevelHeading || foundFrontMatterTitle) {
-          addErrorContext(onError, token.lineNumber,
-            token.line.trim());
-        } else if (token.lineNumber === 1) {
+          const headingTexts = filterByTypes(
+            heading.children,
+            [ "atxHeadingText", "setextHeadingText" ]
+          );
+          const headingText = headingTexts.
+            map((token) => token.text).
+            join(" ").
+            replace(/[\r\n]+/g, " ");
+          addErrorContext(
+            onError,
+            heading.startLine,
+            headingText
+          );
+        } else if (heading.startLine === 1) {
           hasTopLevelHeading = true;
         }
       }
-    });
+    }
   }
 };

test/heading_multiple_toplevel.md

@@ -1,3 +1,9 @@
 # Heading 1
 
 # Heading 2 {MD025}
+
+<p>
+# Not heading
+</p>
+
+<!-- markdownlint-disable-file no-inline-html -->

test/snapshots/markdownlint-test-scenarios.js.md

@@ -653,7 +653,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '# Heading',
+          errorContext: 'Heading',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -2564,7 +2564,7 @@ Generated by [AVA](https://avajs.dev).
     {
       errors: [
         {
-          errorContext: '## Another one {MD025}',
+          errorContext: 'Another one {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -5589,7 +5589,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '> # Quoted heading {MD025}',
+          errorContext: 'Quoted heading {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -5603,7 +5603,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '> > # Double-quoted heading {M...',
+          errorContext: 'Double-quoted heading {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -5617,7 +5617,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '> # Quoted heading in list {MD...',
+          errorContext: 'Quoted heading in list {MD022}...',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -5631,7 +5631,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '> > # Double-quoted heading in...',
+          errorContext: 'Double-quoted heading in list ...',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -13304,7 +13304,7 @@ Generated by [AVA](https://avajs.dev).
     {
       errors: [
         {
-          errorContext: '# Top level heading {MD025}',
+          errorContext: 'Top level heading {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -13556,7 +13556,7 @@ Generated by [AVA](https://avajs.dev).
     {
       errors: [
         {
-          errorContext: '# Another {MD025}',
+          errorContext: 'Another {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -13653,7 +13653,7 @@ Generated by [AVA](https://avajs.dev).
     {
       errors: [
         {
-          errorContext: '# Top level heading {MD025}',
+          errorContext: 'Top level heading {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -14855,7 +14855,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '# A',
+          errorContext: 'A',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -14869,7 +14869,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '# A',
+          errorContext: 'A',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -14883,7 +14883,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '# Heading duplicate content si...',
+          errorContext: 'Heading duplicate content sibl...',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -15147,7 +15147,7 @@ Generated by [AVA](https://avajs.dev).
     {
       errors: [
         {
-          errorContext: '# Heading 2 {MD025}',
+          errorContext: 'Heading 2 {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -15164,6 +15164,12 @@ Generated by [AVA](https://avajs.dev).
       fixed: `# Heading 1␊
       ␊
       # Heading 2 {MD025}␊
+      ␊
+      <p>␊
+      # Not heading␊
+      </p>␊
+      ␊
+      <!-- markdownlint-disable-file no-inline-html -->␊
       `,
     }
 
@@ -16421,7 +16427,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: 'Some text {MD022} {MD025}',
+          errorContext: 'Some text {MD022} {MD025} Head...',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -16435,7 +16441,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: 'Some text {MD022} {MD025}',
+          errorContext: 'Some text {MD022} {MD025} Head...',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -19179,7 +19185,7 @@ Generated by [AVA](https://avajs.dev).
     {
       errors: [
         {
-          errorContext: '# Heading {MD025}',
+          errorContext: 'Heading {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -23886,7 +23892,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '# heading1 {MD025}',
+          errorContext: 'heading1 {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,
@@ -23939,7 +23945,7 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '# header1 {MD025}',
+          errorContext: 'header1 {MD025}',
           errorDetail: null,
           errorRange: null,
           fixInfo: null,