Reimplement MD042/no-empty-links using micromark tokens.

demo/markdownlint-browser.js

@@ -1523,6 +1523,21 @@ function filterByTypes(tokens, types, htmlFlow) {
   return filterByPredicate(tokens, predicate);
 }
 
+/**
+ * Gets a list of nested Micromark token descendants by type path.
+ *
+ * @param {Token|Token[]} parent Micromark token parent or parents.
+ * @param {TokenType[]} typePath Micromark token type path.
+ * @returns {Token[]} Micromark token descendants.
+ */
+function getDescendantsByType(parent, typePath) {
+  let tokens = Array.isArray(parent) ? parent : [ parent ];
+  for (const type of typePath) {
+    tokens = tokens.flatMap((t) => t.children).filter((t) => t.type === type);
+  }
+  return tokens;
+}
+
 /**
  * Gets the heading level of a Micromark heading tokan.
  *
@@ -1691,6 +1706,7 @@ module.exports = {
   "parse": micromarkParse,
   filterByPredicate,
   filterByTypes,
+  getDescendantsByType,
   getHeadingLevel,
   getHeadingStyle,
   getHeadingText,
@@ -5813,8 +5829,9 @@ module.exports = {
 
 
 
-const { addErrorContext, escapeForRegExp, filterTokens } =
+const { addErrorContext } = __webpack_require__(/*! ../helpers */ "../helpers/helpers.js");
-  __webpack_require__(/*! ../helpers */ "../helpers/helpers.js");
+const { getDescendantsByType, filterByTypes } = __webpack_require__(/*! ../helpers/micromark.cjs */ "../helpers/micromark.cjs");
+const { referenceLinkImageData } = __webpack_require__(/*! ./cache */ "../lib/cache.js");
 
 // eslint-disable-next-line jsdoc/valid-types
 /** @type import("./markdownlint").Rule */
@@ -5822,44 +5839,56 @@ module.exports = {
   "names": [ "MD042", "no-empty-links" ],
   "description": "No empty links",
   "tags": [ "links" ],
-  "parser": "markdownit",
+  "parser": "micromark",
   "function": function MD042(params, onError) {
-    filterTokens(params, "inline", function forToken(token) {
+    const { definitions } = referenceLinkImageData();
-      let inLink = false;
+    const isReferenceDefinitionHash = (token) => {
-      let linkText = "";
+      const definition = definitions.get(token.text.trim());
-      let emptyLink = false;
+      return (definition && (definition[1] === "#"));
-      for (const child of token.children) {
+    };
-        if (child.type === "link_open") {
+    const links = filterByTypes(
-          inLink = true;
+      params.parsers.micromark.tokens,
-          linkText = "";
+      [ "link" ]
-          for (const attr of child.attrs) {
+    );
-            if (attr[0] === "href" && (!attr[1] || (attr[1] === "#"))) {
+    for (const link of links) {
-              emptyLink = true;
+      const labelText = getDescendantsByType(link, [ "label", "labelText" ]);
-            }
+      const reference = getDescendantsByType(link, [ "reference" ]);
-          }
+      const resource = getDescendantsByType(link, [ "resource" ]);
-        } else if (child.type === "link_close") {
+      const referenceString = getDescendantsByType(reference, [ "referenceString" ]);
-          inLink = false;
+      const resourceDestination = getDescendantsByType(resource, [ "resourceDestination" ]);
-          if (emptyLink) {
+      const resourceDestinationString = [
-            let context = `[${linkText}]`;
+        ...getDescendantsByType(resourceDestination, [ "resourceDestinationRaw", "resourceDestinationString" ]),
-            let range = null;
+        ...getDescendantsByType(resourceDestination, [ "resourceDestinationLiteral", "resourceDestinationString" ])
-            const match = child.line.match(
+      ];
-              new RegExp(`${escapeForRegExp(context)}\\((?:|#|<>)\\)`)
+      const hasLabelText = labelText.length > 0;
-            );
+      const hasReference = reference.length > 0;
-            if (match) {
+      const hasResource = resource.length > 0;
-              context = match[0];
+      const hasReferenceString = referenceString.length > 0;
-              // @ts-ignore
+      const hasResourceDestinationString = resourceDestinationString.length > 0;
-              range = [ match.index + 1, match[0].length ];
+      let error = false;
-            }
+      if (
-            addErrorContext(
+        hasLabelText &&
-              onError, child.lineNumber, context, null, null, range
+        ((!hasReference && !hasResource) || (hasReference && !hasReferenceString))
-            );
+      ) {
-            emptyLink = false;
+        error = isReferenceDefinitionHash(labelText[0]);
-          }
+      } else if (hasReferenceString && !hasResourceDestinationString) {
-        } else if (inLink) {
+        error = isReferenceDefinitionHash(referenceString[0]);
-          linkText += child.content;
+      } else if (!hasReferenceString && hasResourceDestinationString) {
-        }
+        error = (resourceDestinationString[0].text.trim() === "#");
+      } else if (!hasReferenceString && !hasResourceDestinationString) {
+        error = true;
       }
-    });
+      if (error) {
+        addErrorContext(
+          onError,
+          link.startLine,
+          link.text,
+          undefined,
+          undefined,
+          [ link.startColumn, link.endColumn - link.startColumn ]
+        );
+      }
+    }
   }
 };
 

helpers/micromark.cjs

@@ -304,6 +304,21 @@ function filterByTypes(tokens, types, htmlFlow) {
   return filterByPredicate(tokens, predicate);
 }
 
+/**
+ * Gets a list of nested Micromark token descendants by type path.
+ *
+ * @param {Token|Token[]} parent Micromark token parent or parents.
+ * @param {TokenType[]} typePath Micromark token type path.
+ * @returns {Token[]} Micromark token descendants.
+ */
+function getDescendantsByType(parent, typePath) {
+  let tokens = Array.isArray(parent) ? parent : [ parent ];
+  for (const type of typePath) {
+    tokens = tokens.flatMap((t) => t.children).filter((t) => t.type === type);
+  }
+  return tokens;
+}
+
 /**
  * Gets the heading level of a Micromark heading tokan.
  *
@@ -472,6 +487,7 @@ module.exports = {
   "parse": micromarkParse,
   filterByPredicate,
   filterByTypes,
+  getDescendantsByType,
   getHeadingLevel,
   getHeadingStyle,
   getHeadingText,

lib/md042.js

@@ -2,8 +2,9 @@
 
 "use strict";
 
-const { addErrorContext, escapeForRegExp, filterTokens } =
+const { addErrorContext } = require("../helpers");
-  require("../helpers");
+const { getDescendantsByType, filterByTypes } = require("../helpers/micromark.cjs");
+const { referenceLinkImageData } = require("./cache");
 
 // eslint-disable-next-line jsdoc/valid-types
 /** @type import("./markdownlint").Rule */
@@ -11,43 +12,55 @@ module.exports = {
   "names": [ "MD042", "no-empty-links" ],
   "description": "No empty links",
   "tags": [ "links" ],
-  "parser": "markdownit",
+  "parser": "micromark",
   "function": function MD042(params, onError) {
-    filterTokens(params, "inline", function forToken(token) {
+    const { definitions } = referenceLinkImageData();
-      let inLink = false;
+    const isReferenceDefinitionHash = (token) => {
-      let linkText = "";
+      const definition = definitions.get(token.text.trim());
-      let emptyLink = false;
+      return (definition && (definition[1] === "#"));
-      for (const child of token.children) {
+    };
-        if (child.type === "link_open") {
+    const links = filterByTypes(
-          inLink = true;
+      params.parsers.micromark.tokens,
-          linkText = "";
+      [ "link" ]
-          for (const attr of child.attrs) {
+    );
-            if (attr[0] === "href" && (!attr[1] || (attr[1] === "#"))) {
+    for (const link of links) {
-              emptyLink = true;
+      const labelText = getDescendantsByType(link, [ "label", "labelText" ]);
-            }
+      const reference = getDescendantsByType(link, [ "reference" ]);
-          }
+      const resource = getDescendantsByType(link, [ "resource" ]);
-        } else if (child.type === "link_close") {
+      const referenceString = getDescendantsByType(reference, [ "referenceString" ]);
-          inLink = false;
+      const resourceDestination = getDescendantsByType(resource, [ "resourceDestination" ]);
-          if (emptyLink) {
+      const resourceDestinationString = [
-            let context = `[${linkText}]`;
+        ...getDescendantsByType(resourceDestination, [ "resourceDestinationRaw", "resourceDestinationString" ]),
-            let range = null;
+        ...getDescendantsByType(resourceDestination, [ "resourceDestinationLiteral", "resourceDestinationString" ])
-            const match = child.line.match(
+      ];
-              new RegExp(`${escapeForRegExp(context)}\\((?:|#|<>)\\)`)
+      const hasLabelText = labelText.length > 0;
-            );
+      const hasReference = reference.length > 0;
-            if (match) {
+      const hasResource = resource.length > 0;
-              context = match[0];
+      const hasReferenceString = referenceString.length > 0;
-              // @ts-ignore
+      const hasResourceDestinationString = resourceDestinationString.length > 0;
-              range = [ match.index + 1, match[0].length ];
+      let error = false;
-            }
+      if (
-            addErrorContext(
+        hasLabelText &&
-              onError, child.lineNumber, context, null, null, range
+        ((!hasReference && !hasResource) || (hasReference && !hasReferenceString))
-            );
+      ) {
-            emptyLink = false;
+        error = isReferenceDefinitionHash(labelText[0]);
-          }
+      } else if (hasReferenceString && !hasResourceDestinationString) {
-        } else if (inLink) {
+        error = isReferenceDefinitionHash(referenceString[0]);
-          linkText += child.content;
+      } else if (!hasReferenceString && hasResourceDestinationString) {
-        }
+        error = (resourceDestinationString[0].text.trim() === "#");
+      } else if (!hasReferenceString && !hasResourceDestinationString) {
+        error = true;
       }
-    });
+      if (error) {
+        addErrorContext(
+          onError,
+          link.startLine,
+          link.text,
+          undefined,
+          undefined,
+          [ link.startColumn, link.endColumn - link.startColumn ]
+        );
+      }
+    }
   }
 };

test/empty-links.md

@@ -24,6 +24,10 @@
 
 [text][ frag ] {MD042}
 
+[frag][] {MD042}
+
+[frag] {MD042}
+
 [frag]: #
 
 ## Non-empty links

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

@@ -11837,9 +11837,12 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '[text]',
+          errorContext: '[text]( <> )',
           errorDetail: null,
-          errorRange: null,
+          errorRange: [
+            1,
+            12,
+          ],
           fixInfo: null,
           lineNumber: 9,
           ruleDescription: 'No empty links',
@@ -11850,9 +11853,12 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '[text]',
+          errorContext: '[text](<> "title")',
           errorDetail: null,
-          errorRange: null,
+          errorRange: [
+            1,
+            18,
+          ],
           fixInfo: null,
           lineNumber: 11,
           ruleDescription: 'No empty links',
@@ -11863,9 +11869,12 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '[text]',
+          errorContext: '[text]( <> "title" )',
           errorDetail: null,
-          errorRange: null,
+          errorRange: [
+            1,
+            20,
+          ],
           fixInfo: null,
           lineNumber: 13,
           ruleDescription: 'No empty links',
@@ -11892,9 +11901,12 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '[text]',
+          errorContext: '[text]( # )',
           errorDetail: null,
-          errorRange: null,
+          errorRange: [
+            1,
+            11,
+          ],
           fixInfo: null,
           lineNumber: 17,
           ruleDescription: 'No empty links',
@@ -11905,9 +11917,12 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '[text]',
+          errorContext: '[text](# "title")',
           errorDetail: null,
-          errorRange: null,
+          errorRange: [
+            1,
+            17,
+          ],
           fixInfo: null,
           lineNumber: 19,
           ruleDescription: 'No empty links',
@@ -11918,9 +11933,12 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '[text]',
+          errorContext: '[text]( # "title" )',
           errorDetail: null,
-          errorRange: null,
+          errorRange: [
+            1,
+            19,
+          ],
           fixInfo: null,
           lineNumber: 21,
           ruleDescription: 'No empty links',
@@ -11931,9 +11949,12 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '[text]',
+          errorContext: '[text][frag]',
           errorDetail: null,
-          errorRange: null,
+          errorRange: [
+            1,
+            12,
+          ],
           fixInfo: null,
           lineNumber: 23,
           ruleDescription: 'No empty links',
@@ -11944,9 +11965,12 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '[text]',
+          errorContext: '[text][ frag ]',
           errorDetail: null,
-          errorRange: null,
+          errorRange: [
+            1,
+            14,
+          ],
           fixInfo: null,
           lineNumber: 25,
           ruleDescription: 'No empty links',
@@ -11957,14 +11981,30 @@ Generated by [AVA](https://avajs.dev).
           ],
         },
         {
-          errorContext: '[text]()',
+          errorContext: '[frag][]',
           errorDetail: null,
           errorRange: [
             1,
             8,
           ],
           fixInfo: null,
-          lineNumber: 70,
+          lineNumber: 27,
+          ruleDescription: 'No empty links',
+          ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md042.md',
+          ruleNames: [
+            'MD042',
+            'no-empty-links',
+          ],
+        },
+        {
+          errorContext: '[frag]',
+          errorDetail: null,
+          errorRange: [
+            1,
+            6,
+          ],
+          fixInfo: null,
+          lineNumber: 29,
           ruleDescription: 'No empty links',
           ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md042.md',
           ruleNames: [
@@ -11996,7 +12036,7 @@ Generated by [AVA](https://avajs.dev).
             8,
           ],
           fixInfo: null,
-          lineNumber: 76,
+          lineNumber: 78,
           ruleDescription: 'No empty links',
           ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md042.md',
           ruleNames: [
@@ -12012,7 +12052,7 @@ Generated by [AVA](https://avajs.dev).
             8,
           ],
           fixInfo: null,
-          lineNumber: 79,
+          lineNumber: 80,
           ruleDescription: 'No empty links',
           ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md042.md',
           ruleNames: [
@@ -12028,7 +12068,23 @@ Generated by [AVA](https://avajs.dev).
             8,
           ],
           fixInfo: null,
-          lineNumber: 81,
+          lineNumber: 83,
+          ruleDescription: 'No empty links',
+          ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md042.md',
+          ruleNames: [
+            'MD042',
+            'no-empty-links',
+          ],
+        },
+        {
+          errorContext: '[text]()',
+          errorDetail: null,
+          errorRange: [
+            1,
+            8,
+          ],
+          fixInfo: null,
+          lineNumber: 85,
           ruleDescription: 'No empty links',
           ruleInformation: 'https://github.com/DavidAnson/markdownlint/blob/v0.0.0/doc/md042.md',
           ruleNames: [
@@ -12063,6 +12119,10 @@ Generated by [AVA](https://avajs.dev).
       ␊
       [text][ frag ] {MD042}␊
       ␊
+      [frag][] {MD042}␊
+      ␊
+      [frag] {MD042}␊
+      ␊
       [frag]: #␊
       ␊
       ## Non-empty links␊