Update MD051/link-fragments to handle links and images in headings (fixes #945).

Author: DavidAnson

demo/markdownlint-browser.js

@@ -6139,6 +6139,7 @@ var _require = __webpack_require__(/*! ../helpers */ "../helpers/helpers.js"),
   addError = _require.addError,
   addErrorDetailIf = _require.addErrorDetailIf;
 var _require2 = __webpack_require__(/*! ../helpers/micromark.cjs */ "../helpers/micromark.cjs"),
+  filterByPredicate = _require2.filterByPredicate,
   filterByTypes = _require2.filterByTypes,
   getHtmlTagInfo = _require2.getHtmlTagInfo;
 
@@ -6147,6 +6148,10 @@ var idRe = /[\t-\r \xA0\u1680\u2000-\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF]i
 var nameRe = /[\t-\r \xA0\u1680\u2000-\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF]name[\t-\r \xA0\u1680\u2000-\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF]*=[\t-\r \xA0\u1680\u2000-\u200A\u2028\u2029\u202F\u205F\u3000\uFEFF]*["']?((?:(?![\t-\r "'>\xA0\u1680\u2000-\u200A\u2028\u2029\u202F\u205F\u3000\uD800-\uDFFF\uFEFF])[\s\S]|[\uD800-\uDBFF][\uDC00-\uDFFF])+)/i;
 var anchorRe = /\{(#[0-9a-z]+(?:[\x2D_][0-9a-z]+)*)\}/g;
 
+// Sets for filtering heading tokens during conversion
+var childrenExclude = new Set(["image", "reference", "resource"]);
+var tokensInclude = new Set(["codeTextData", "data"]);
+
 /**
  * Converts a Markdown heading into an HTML fragment according to the rules
  * used by GitHub.
@@ -6155,7 +6160,11 @@ var anchorRe = /\{(#[0-9a-z]+(?:[\x2D_][0-9a-z]+)*)\}/g;
  * @returns {string} Fragment string for heading.
  */
 function convertHeadingToHTMLFragment(headingText) {
-  var inlineText = filterByTypes(headingText.children, ["codeTextData", "data"]).map(function (token) {
+  var inlineText = filterByPredicate(headingText.children, function (token) {
+    return tokensInclude.has(token.type);
+  }, function (token) {
+    return childrenExclude.has(token.type) ? [] : token.children;
+  }).map(function (token) {
     return token.text;
   }).join("");
   return "#" + encodeURIComponent(inlineText.toLowerCase()
@@ -6181,18 +6190,20 @@ module.exports = {
       for (_iterator.s(); !(_step = _iterator.n()).done;) {
         var headingText = _step.value;
         var fragment = convertHeadingToHTMLFragment(headingText);
-        var count = fragments.get(fragment) || 0;
-        if (count) {
-          fragments.set("".concat(fragment, "-").concat(count), 0);
-        }
-        fragments.set(fragment, count + 1);
-        var match = null;
-        while ((match = anchorRe.exec(headingText.text)) !== null) {
-          var _match = match,
-            _match2 = _slicedToArray(_match, 2),
-            anchor = _match2[1];
-          if (!fragments.has(anchor)) {
-            fragments.set(anchor, 1);
+        if (fragment !== "#") {
+          var count = fragments.get(fragment) || 0;
+          if (count) {
+            fragments.set("".concat(fragment, "-").concat(count), 0);
+          }
+          fragments.set(fragment, count + 1);
+          var match = null;
+          while ((match = anchorRe.exec(headingText.text)) !== null) {
+            var _match = match,
+              _match2 = _slicedToArray(_match, 2),
+              anchor = _match2[1];
+            if (!fragments.has(anchor)) {
+              fragments.set(anchor, 1);
+            }
           }
         }
       }

lib/md051.js

@@ -3,13 +3,18 @@
 "use strict";
 
 const { addError, addErrorDetailIf } = require("../helpers");
-const { filterByTypes, getHtmlTagInfo } = require("../helpers/micromark.cjs");
+const { filterByPredicate, filterByTypes, getHtmlTagInfo } =
+  require("../helpers/micromark.cjs");
 
 // Regular expression for identifying HTML anchor names
 const idRe = /\sid\s*=\s*['"]?([^'"\s>]+)/iu;
 const nameRe = /\sname\s*=\s*['"]?([^'"\s>]+)/iu;
 const anchorRe = /\{(#[a-z\d]+(?:[-_][a-z\d]+)*)\}/gu;
 
+// Sets for filtering heading tokens during conversion
+const childrenExclude = new Set([ "image", "reference", "resource" ]);
+const tokensInclude = new Set([ "codeTextData", "data" ]);
+
 /**
  * Converts a Markdown heading into an HTML fragment according to the rules
  * used by GitHub.
@@ -19,7 +24,11 @@ const anchorRe = /\{(#[a-z\d]+(?:[-_][a-z\d]+)*)\}/gu;
  */
 function convertHeadingToHTMLFragment(headingText) {
   const inlineText =
-    filterByTypes(headingText.children, [ "codeTextData", "data" ])
+    filterByPredicate(
+      headingText.children,
+      (token) => tokensInclude.has(token.type),
+      (token) => (childrenExclude.has(token.type) ? [] : token.children)
+    )
       .map((token) => token.text)
       .join("");
   return "#" + encodeURIComponent(
@@ -52,16 +61,18 @@ module.exports = {
     );
     for (const headingText of headingTexts) {
       const fragment = convertHeadingToHTMLFragment(headingText);
-      const count = fragments.get(fragment) || 0;
-      if (count) {
-        fragments.set(`${fragment}-${count}`, 0);
-      }
-      fragments.set(fragment, count + 1);
-      let match = null;
-      while ((match = anchorRe.exec(headingText.text)) !== null) {
-        const [ , anchor ] = match;
-        if (!fragments.has(anchor)) {
-          fragments.set(anchor, 1);
+      if (fragment !== "#") {
+        const count = fragments.get(fragment) || 0;
+        if (count) {
+          fragments.set(`${fragment}-${count}`, 0);
+        }
+        fragments.set(fragment, count + 1);
+        let match = null;
+        while ((match = anchorRe.exec(headingText.text)) !== null) {
+          const [ , anchor ] = match;
+          if (!fragments.has(anchor)) {
+            fragments.set(anchor, 1);
+          }
         }
       }
     }

test/link-fragments.md

@@ -46,6 +46,16 @@
 
 [Valid](#en-t%C3%AAte-valide-dans-fran%C3%A7ais-pour-v%C3%A9rification)
 
+[Valid](#valid-heading-is-a-link)
+
+[Valid](#valid-heading-has-a-link)
+
+[Valid](#valid-heading-is-a-reference-link)
+
+[Valid](#valid-heading-has-a-reference-link)
+
+[Valid](#valid-heading-has-)
+
 [Valid](#namedlink)
 
 [Valid](#idlink)
@@ -127,6 +137,18 @@ Text
 
 ### En-tête Valide Dans Français Pour Vérification
 
+### [Valid Heading Is a Link](https://example.com)
+
+### Valid Heading [Has a Link](https://example.com)
+
+### [Valid Heading Is a Reference Link][goodref]
+
+### Valid Heading [Has a Reference Link][goodref]
+
+### ![Valid Heading Is an Image](https://example.com)
+
+### Valid Heading Has ![an Image](https://example.com)
+
 <a name="namedlink"></a>
 
 <a id = idlink></a>
@@ -147,6 +169,8 @@ Text
 
 ## Invalid Fragments
 
+[Invalid](#valid-heading-is-an-image) {MD051}
+
 [Invalid](#valid-heading-2004-) {MD051}
 
 [Invalid](#valid-repeated-heading-3) {MD051}