Move markdown-it token manipulation code into a separate file which is only require()-ed if/when needed.

lib/markdownlint.js

@@ -197,87 +197,6 @@ function removeFrontMatter(content, frontMatter) {
   };
 }
 
-/**
- * Freeze all freeze-able members of a token and its children.
- *
- * @param {MarkdownItToken} token A markdown-it token.
- * @returns {void}
- */
-function freezeToken(token) {
-  if (token.attrs) {
-    for (const attr of token.attrs) {
-      Object.freeze(attr);
-    }
-    Object.freeze(token.attrs);
-  }
-  if (token.children) {
-    for (const child of token.children) {
-      freezeToken(child);
-    }
-    Object.freeze(token.children);
-  }
-  if (token.map) {
-    Object.freeze(token.map);
-  }
-  Object.freeze(token);
-}
-
-/**
- * Annotate tokens with line/lineNumber and freeze them.
- *
- * @param {import("markdown-it").Token[]} tokens Array of markdown-it tokens.
- * @param {string[]} lines Lines of Markdown content.
- * @returns {void}
- */
-function annotateAndFreezeTokens(tokens, lines) {
-  let trMap = null;
-  // eslint-disable-next-line jsdoc/valid-types
-  /** @type MarkdownItToken[] */
-  // @ts-ignore
-  const markdownItTokens = tokens;
-  for (const token of markdownItTokens) {
-    // Provide missing maps for table content
-    if (token.type === "tr_open") {
-      trMap = token.map;
-    } else if (token.type === "tr_close") {
-      trMap = null;
-    }
-    if (!token.map && trMap) {
-      token.map = [ ...trMap ];
-    }
-    // Update token metadata
-    if (token.map) {
-      token.line = lines[token.map[0]];
-      token.lineNumber = token.map[0] + 1;
-      // Trim bottom of token to exclude whitespace lines
-      while (token.map[1] && !((lines[token.map[1] - 1] || "").trim())) {
-        token.map[1]--;
-      }
-    }
-    // Annotate children with lineNumber
-    if (token.children) {
-      const codeSpanExtraLines = [];
-      if (token.children.some((child) => child.type === "code_inline")) {
-        helpers.forEachInlineCodeSpan(token.content, (code) => {
-          codeSpanExtraLines.push(code.split(helpers.newLineRe).length - 1);
-        });
-      }
-      let lineNumber = token.lineNumber;
-      for (const child of token.children) {
-        child.lineNumber = lineNumber;
-        child.line = lines[lineNumber - 1];
-        if ((child.type === "softbreak") || (child.type === "hardbreak")) {
-          lineNumber++;
-        } else if (child.type === "code_inline") {
-          lineNumber += codeSpanExtraLines.shift();
-        }
-      }
-    }
-    freezeToken(token);
-  }
-  Object.freeze(tokens);
-}
-
 /**
  * Map rule names/tags to canonical rule name.
  *
@@ -533,7 +452,7 @@ function getEnabledRulesPerLineNumber(
  * names.
  * @param {string} name Identifier for the content.
  * @param {string} content Markdown content.
- * @param {GetMarkdownIt} getMarkdownIt Getter for instance of markdown-it.
+ * @param {Plugin[]} markdownItPlugins Additional plugins.
  * @param {Configuration} config Configuration object.
  * @param {ConfigurationParser[] | null} configParsers Configuration parsers.
  * @param {RegExp | null} frontMatter Regular expression for front matter.
@@ -548,7 +467,7 @@ function lintContent(
   aliasToRuleNames,
   name,
   content,
-  getMarkdownIt,
+  markdownItPlugins,
   config,
   configParsers,
   frontMatter,
@@ -577,13 +496,15 @@ function lintContent(
     (rule) => (rule.parser === "markdownit") || (rule.parser === undefined)
   );
   // Parse content into parser tokens
-  const markdownitTokens = needMarkdownItTokens ? getMarkdownIt().parse(content, {}) : [];
   const micromarkTokens = micromark.parse(content);
   // Hide the content of HTML comments from rules
+  const preClearedContent = content;
   content = helpers.clearHtmlCommentText(content);
-  // Parse content into lines and update markdown-it tokens
+  // Parse content into lines and get markdown-it tokens
   const lines = content.split(helpers.newLineRe);
-  annotateAndFreezeTokens(markdownitTokens, lines);
+  const markdownitTokens = needMarkdownItTokens ?
+    require("./markdownit.cjs").getMarkdownItTokens(markdownItPlugins, preClearedContent, lines) :
+    [];
   // Create (frozen) parameters for rules
   /** @type {MarkdownParsers} */
   // @ts-ignore
@@ -836,7 +757,7 @@ function lintContent(
  * @param {Object.<string, string[]>} aliasToRuleNames Map of alias to rule
  * names.
  * @param {string} file Path of file to lint.
- * @param {GetMarkdownIt} getMarkdownIt Getter for instance of markdown-it.
+ * @param {Plugin[]} markdownItPlugins Additional plugins.
  * @param {Configuration} config Configuration object.
  * @param {ConfigurationParser[] | null} configParsers Configuration parsers.
  * @param {RegExp | null} frontMatter Regular expression for front matter.
@@ -852,7 +773,7 @@ function lintFile(
   ruleList,
   aliasToRuleNames,
   file,
-  getMarkdownIt,
+  markdownItPlugins,
   config,
   configParsers,
   frontMatter,
@@ -872,7 +793,7 @@ function lintFile(
       aliasToRuleNames,
       file,
       content,
-      getMarkdownIt,
+      markdownItPlugins,
       config,
       configParsers,
       frontMatter,
@@ -939,16 +860,7 @@ function lintInput(options, synchronous, callback) {
   const resultVersion = (options.resultVersion === undefined) ?
     3 :
     options.resultVersion;
-  const getMarkdownIt = () => {
-    const markdownit = require("markdown-it");
-    const md = markdownit({ "html": true });
-    const markdownItPlugins = options.markdownItPlugins || [];
-    for (const plugin of markdownItPlugins) {
-      // @ts-ignore
-      md.use(...plugin);
-    }
-    return md;
-  };
+  const markdownItPlugins = options.markdownItPlugins || [];
   const fs = options.fs || require("node:fs");
   const aliasToRuleNames = mapAliasToRuleNames(ruleList);
   const results = newResults(ruleList);
@@ -980,7 +892,7 @@ function lintInput(options, synchronous, callback) {
         ruleList,
         aliasToRuleNames,
         currentItem,
-        getMarkdownIt,
+        markdownItPlugins,
         config,
         configParsers,
         frontMatter,
@@ -999,7 +911,7 @@ function lintInput(options, synchronous, callback) {
         aliasToRuleNames,
         currentItem,
         strings[currentItem] || "",
-        getMarkdownIt,
+        markdownItPlugins,
         config,
         configParsers,
         frontMatter,
@@ -1314,13 +1226,6 @@ module.exports = markdownlint;
 
 // Type declarations
 
-/**
- * Function to get an instance of the markdown-it parser.
- *
- * @callback GetMarkdownIt
- * @returns {import("markdown-it")}
- */
-
 /**
  * Function to implement rule logic.
  *