Add Rule.parser property for custom rules to specify which Markdown parser output they use, honor it strictly, and add full type support.

lib/markdownlint.js

@@ -33,17 +33,16 @@ function validateRuleList(ruleList, synchronous) {
   for (const [ index, rule ] of ruleList.entries()) {
     const customIndex = index - rules.length;
     // eslint-disable-next-line no-inner-declarations, jsdoc/require-jsdoc
-    function newError(property) {
+    function newError(property, value) {
       return new Error(
-        "Property '" + property + "' of custom rule at index " +
-        customIndex + " is incorrect.");
+        `Property '${property}' of custom rule at index ${customIndex} is incorrect: '${value}'.`);
     }
     for (const property of [ "names", "tags" ]) {
       const value = rule[property];
       if (!result &&
         (!value || !Array.isArray(value) || (value.length === 0) ||
          !value.every(helpers.isString) || value.some(helpers.isEmptyString))) {
-        result = newError(property);
+        result = newError(property, value);
       }
     }
     for (const propertyInfo of [
@@ -53,22 +52,31 @@ function validateRuleList(ruleList, synchronous) {
       const property = propertyInfo[0];
       const value = rule[property];
       if (!result && (!value || (typeof value !== propertyInfo[1]))) {
-        result = newError(property);
+        result = newError(property, value);
       }
     }
+    if (
+      !result &&
+      (rule.parser !== undefined) &&
+      (rule.parser !== "markdownit") &&
+      !((customIndex < 0) && (rule.parser === "micromark")) &&
+      (rule.parser !== "none")
+    ) {
+      result = newError("parser", rule.parser);
+    }
     if (
       !result &&
       rule.information &&
       !helpers.isUrl(rule.information)
     ) {
-      result = newError("information");
+      result = newError("information", rule.information);
     }
     if (
       !result &&
       (rule.asynchronous !== undefined) &&
       (typeof rule.asynchronous !== "boolean")
     ) {
-      result = newError("asynchronous");
+      result = newError("asynchronous", rule.asynchronous);
     }
     if (!result && rule.asynchronous && synchronous) {
       result = new Error(
@@ -563,18 +571,26 @@ function lintContent(
   const lines = content.split(helpers.newLineRe);
   annotateAndFreezeTokens(markdownitTokens, lines);
   // Create (frozen) parameters for rules
-  const parsers = Object.freeze({
+  /** @type {MarkdownParsers} */
+  // @ts-ignore
+  const parsersMarkdownIt = Object.freeze({
     "markdownit": Object.freeze({
       "tokens": markdownitTokens
-    }),
+    })
+  });
+  /** @type {MarkdownParsers} */
+  // @ts-ignore
+  const parsersMicromark = Object.freeze({
     "micromark": Object.freeze({
       "tokens": micromarkTokens
     })
   });
+  /** @type {MarkdownParsers} */
+  // @ts-ignore
+  const parsersNone = Object.freeze({});
   const paramsBase = {
     name,
-    parsers,
-    "tokens": markdownitTokens,
+    "parsers": parsersMarkdownIt,
     "lines": Object.freeze(lines),
     "frontMatterLines": Object.freeze(frontMatterLines)
   };
@@ -583,9 +599,9 @@ function lintContent(
   const codeBlockAndSpanRanges =
     helpers.codeBlockAndSpanRanges(paramsBase, lineMetadata);
   const flattenedLists =
-    helpers.flattenLists(paramsBase.parsers.markdownit.tokens);
+    helpers.flattenLists(markdownitTokens);
   const referenceLinkImageData =
-    helpers.getReferenceLinkImageData(paramsBase);
+    helpers.getReferenceLinkImageData(micromarkTokens);
   cache.set({
     codeBlockAndSpanRanges,
     flattenedLists,
@@ -594,12 +610,27 @@ function lintContent(
   });
   // Function to run for each rule
   let results = [];
-  // eslint-disable-next-line jsdoc/require-jsdoc
-  function forRule(rule) {
+  /**
+   * @param {Rule} rule Rule.
+   * @returns {Promise<void> | null} Promise.
+   */
+  const forRule = (rule) => {
     // Configure rule
     const ruleName = rule.names[0].toUpperCase();
+    const tokens = {};
+    let parsers = parsersNone;
+    if (rule.parser === undefined) {
+      tokens.tokens = markdownitTokens;
+      parsers = parsersMarkdownIt;
+    } else if (rule.parser === "markdownit") {
+      parsers = parsersMarkdownIt;
+    } else if (rule.parser === "micromark") {
+      parsers = parsersMicromark;
+    }
     const params = {
       ...paramsBase,
+      ...tokens,
+      parsers,
       "config": effectiveConfig[ruleName]
     };
     // eslint-disable-next-line jsdoc/require-jsdoc
@@ -875,6 +906,7 @@ function lintInput(options, synchronous, callback) {
         "description": rule.description,
         "information": helpers.cloneIfUrl(rule.information),
         "tags": helpers.cloneIfArray(rule.tags),
+        "parser": rule.parser,
         "asynchronous": rule.asynchronous,
         "function": rule.function
       }));
@@ -1281,22 +1313,27 @@ module.exports = markdownlint;
  * @returns {void}
  */
 
+/* eslint-disable jsdoc/valid-types */
+
 /**
  * Rule parameters.
  *
  * @typedef {Object} RuleParams
  * @property {string} name File/string name.
  * @property {MarkdownParsers} parsers Markdown parser data.
- * @property {string[]} lines File/string lines.
- * @property {string[]} frontMatterLines Front matter lines.
+ * @property {readonly string[]} lines File/string lines.
+ * @property {readonly string[]} frontMatterLines Front matter lines.
  * @property {RuleConfiguration} config Rule configuration.
  */
 
+/* eslint-enable jsdoc/valid-types */
+
 /**
  * Markdown parser data.
  *
  * @typedef {Object} MarkdownParsers
- * @property {ParserMarkdownIt} markdownit Markdown parser data from markdown-it.
+ * @property {ParserMarkdownIt} markdownit Markdown parser data from markdown-it (only present when Rule.parser is "markdownit").
+ * @property {ParserMicromark} micromark Markdown parser data from micromark (only present when Rule.parser is "micromark").
  */
 
 /**
@@ -1306,6 +1343,13 @@ module.exports = markdownlint;
  * @property {MarkdownItToken[]} tokens Token objects from markdown-it.
  */
 
+/**
+ * Markdown parser data from micromark.
+ *
+ * @typedef {Object} ParserMicromark
+ * @property {MicromarkToken[]} tokens Token objects from micromark.
+ */
+
 /**
  * markdown-it token.
  *
@@ -1327,6 +1371,22 @@ module.exports = markdownlint;
  * @property {string} line Line content.
  */
 
+/** @typedef {import("markdownlint-micromark").TokenType} MicromarkTokenType */
+
+/**
+ * micromark token.
+ *
+ * @typedef {Object} MicromarkToken
+ * @property {MicromarkTokenType} type Token type.
+ * @property {number} startLine Start line (1-based).
+ * @property {number} startColumn Start column (1-based).
+ * @property {number} endLine End line (1-based).
+ * @property {number} endColumn End column (1-based).
+ * @property {string} text Token text.
+ * @property {MicromarkToken[]} children Child tokens.
+ * @property {MicromarkToken | null} parent Parent token.
+ */
+
 /**
  * Error-reporting callback.
  *
@@ -1365,6 +1425,7 @@ module.exports = markdownlint;
  * @property {string} description Rule description.
  * @property {URL} [information] Link to more information.
  * @property {string[]} tags Rule tag(s).
+ * @property {"markdownit" | "micromark" | "none"} parser Parser used.
  * @property {boolean} [asynchronous] True if asynchronous.
  * @property {RuleFunction} function Rule implementation.
  */