Update: compatibility with eslint-mdx

.eslintrc.js

@@ -33,7 +33,11 @@ module.exports = {
     "overrides": [
         {
             "files": ["**/*.md"],
-            "processor": "markdown/markdown"
+            "extends": ["plugin:mdx/recommended"],
+            "processor": "markdown/markdown",
+            "rules": {
+                "mdx/remark": 0
+            }
         },
         {
             "files": ["**/*.md/*.js"],

.gitignore

@@ -4,3 +4,6 @@ node_modules/
 npm-debug.log
 .eslint-release-info.json
 .nyc_output
+package-lock.json
+yarn.lock
+types

lib/processor.js

@@ -1,6 +1,11 @@
 /**
  * @fileoverview Processes Markdown files for consumption by ESLint.
  * @author Brandon Mills
+ *
+ * @typedef {import('unist').Node} ASTNode
+ * @typedef {ASTNode & {children: ASTNode[]}} ASTParentNode
+ * @typedef {import('eslint').Linter.LintMessage} Message
+ * @typedef {ASTNode & {baseIndentText: string, comments: string[], rangeMap: Array<{js: number, md: number}>}} Block
  */
 
 "use strict";
@@ -16,13 +21,13 @@ const SUPPORTS_AUTOFIX = true;
 
 const markdown = unified().use(remarkParse);
 
-let blocks = [];
+const blocksCache = {};
 
 /**
  * Performs a depth-first traversal of the Markdown AST.
  * @param {ASTNode} node A Markdown AST node.
- * @param {Object} callbacks A map of node types to callbacks.
- * @param {Object} [parent] The node's parent AST node.
+ * @param {{[key: string]: (node: ASTNode, parent: ASTParentNode) => void}} callbacks A map of node types to callbacks.
+ * @param {ASTParentNode} [parent] The node's parent AST node.
  * @returns {void}
  */
 function traverse(node, callbacks, parent) {
@@ -40,7 +45,7 @@ function traverse(node, callbacks, parent) {
 /**
  * Converts leading HTML comments to JS block comments.
  * @param {string} html The text content of an HTML AST node.
- * @returns {string[]} An array of JS block comments.
+ * @returns {string} JS block comment.
  */
 function getComment(html) {
     const commentStart = "<!--";
@@ -116,9 +121,9 @@ function getIndentText(text, node) {
  * delta at the beginning of each line.
  * @param {string} text The text of the file.
  * @param {ASTNode} node A Markdown code block AST node.
- * @param {comments} comments List of configuration comment strings that will be
+ * @param {string[]} comments List of configuration comment strings that will be
  *     inserted at the beginning of the code block.
- * @returns {Object[]} A list of offset-based adjustments, where lookups are
+ * @returns {Array<{js: number, md: number}>} A list of offset-based adjustments, where lookups are
  *     done based on the `js` key, which represents the range in the linted JS,
  *     and the `md` key is the offset delta that, when added to the JS range,
  *     returns the corresponding location in the original Markdown source.
@@ -128,7 +133,7 @@ function getBlockRangeMap(text, node, comments) {
     /*
      * The parser sets the fenced code block's start offset to wherever content
      * should normally begin (typically the first column of the line, but more
-     * inside a list item, for example). The code block's opening fance may be
+     * inside a list item, for example). The code block's opening fancy may be
      * further indented by up to three characters. If the code block has
      * additional indenting, the opening fence's first backtick may be up to
      * three whitespace characters after the start offset.
@@ -208,15 +213,52 @@ function getBlockRangeMap(text, node, comments) {
     return rangeMap;
 }
 
+const LANGUAGES_MAPPER = {
+    javascript: "js",
+    javascriptreact: "jsx",
+    typescript: "ts",
+    typescriptreact: "tsx",
+    markdown: "md",
+    mdown: "md",
+    mkdn: "md"
+};
+
+/**
+ * get last item from array
+ * @template T
+ * @param {T[]} items array
+ * @returns {T} last item
+ */
+function last(items) {
+    return items && items[items.length - 1];
+}
+
+/**
+ * get short language
+ * @param {string} lang original language
+ * @returns {string} short language
+ */
+function getShortLang(lang) {
+    const language = last(
+        lang.split(/\s/u)[0].split(".")
+    ).toLowerCase();
+
+    return LANGUAGES_MAPPER[language] || language;
+}
+
+
 /**
  * Extracts lintable JavaScript code blocks from Markdown text.
  * @param {string} text The text of the file.
- * @returns {string[]} Source code strings to lint.
+ * @param {string} filename The filename of the file
+ * @returns {Array<string | {text: string, filename: string}>} Source code strings to lint.
  */
-function preprocess(text) {
+function preprocess(text, filename) {
     const ast = markdown.parse(text);
+    const blocks = [];
+
+    blocksCache[filename] = blocks;
 
-    blocks = [];
     traverse(ast, {
         code(node, parent) {
             const comments = [];
@@ -252,7 +294,7 @@ function preprocess(text) {
     });
 
     return blocks.map((block, index) => ({
-        filename: `${index}.${block.lang.trim().split(" ")[0]}`,
+        filename: `${index}.${getShortLang(block.lang)}`,
         text: [
             ...block.comments,
             block.value,
@@ -264,7 +306,7 @@ function preprocess(text) {
 /**
  * Creates a map function that adjusts messages in a code block.
  * @param {Block} block A code block.
- * @returns {Function} A function that adjusts messages in a code block.
+ * @returns {(message: Message) => Message} A function that adjusts messages in a code block.
  */
 function adjustBlock(block) {
     const leadingCommentLines = block.comments.reduce((count, comment) => count + comment.split("\n").length, 0);
@@ -330,13 +372,22 @@ function excludeUnsatisfiableRules(message) {
 
 /**
  * Transforms generated messages for output.
- * @param {Array<Message[]>} messages An array containing one array of messages
- *     for each code block returned from `preprocess`.
+ * @param {Array<Message[]>} messages An array containing one array of messages for each code block returned from `preprocess`.
+ * @param {string} filename The filename of the file
  * @returns {Message[]} A flattened array of messages with mapped locations.
  */
-function postprocess(messages) {
+function postprocess(messages, filename) {
+    const blocks = blocksCache[filename] || [];
+
     return [].concat(...messages.map((group, i) => {
-        const adjust = adjustBlock(blocks[i]);
+        const block = blocks[i];
+
+        // non code block message, parsed by `eslint-mdx` for example
+        if (!block) {
+            return group;
+        }
+
+        const adjust = adjustBlock(block);
 
         return group.map(adjust).filter(excludeUnsatisfiableRules);
     }));

package.json

@@ -24,31 +24,36 @@
     "prepare": "node ./npm-prepare.js",
     "test": "npm run lint && npm run test-cov",
     "test-cov": "nyc _mocha -- -c tests/{examples,lib}/**/*.js",
+    "types": "tsc lib/*.js -d --allowJs --emitDeclarationOnly --lib ES2015 --outDir types",
     "generate-release": "eslint-generate-release",
     "generate-alpharelease": "eslint-generate-prerelease alpha",
     "generate-betarelease": "eslint-generate-prerelease beta",
     "generate-rcrelease": "eslint-generate-prerelease rc",
     "publish-release": "eslint-publish-release"
   },
   "main": "index.js",
+  "types": "types/index.d.ts",
   "files": [
     "index.js",
-    "lib/index.js",
-    "lib/processor.js"
+    "lib",
+    "types"
   ],
   "devDependencies": {
+    "@types/eslint": "^7.2.7",
     "chai": "^4.2.0",
     "eslint": "^6.8.0",
     "eslint-config-eslint": "^6.0.0",
     "eslint-plugin-jsdoc": "^15.9.5",
+    "eslint-plugin-mdx": "^1.9.1",
     "eslint-plugin-node": "^9.0.0",
     "eslint-release": "^3.1.2",
     "mocha": "^6.2.2",
-    "nyc": "^14.1.1"
+    "nyc": "^14.1.1",
+    "typescript": "^4.2.3"
   },
   "dependencies": {
-    "remark-parse": "^5.0.0",
-    "unified": "^6.1.2"
+    "remark-parse": ">=5.0.0 <9.0.0",
+    "unified": ">=6.0.0"
   },
   "peerDependencies": {
     "eslint": ">=6.0.0"

tests/lib/processor.js

@@ -117,7 +117,7 @@ describe("processor", () => {
             assert.strictEqual(blocks.length, 2);
             assert.strictEqual(blocks[0].filename, "0.js");
             assert.strictEqual(blocks[0].text, "backticks\n");
-            assert.strictEqual(blocks[1].filename, "1.javascript");
+            assert.strictEqual(blocks[1].filename, "1.js");
             assert.strictEqual(blocks[1].text, "tildes\n");
         });
 
@@ -199,7 +199,7 @@ describe("processor", () => {
 
             assert.strictEqual(blocks.length, 1);
             assert.strictEqual(blocks[0].filename, "0.js");
-            assert.strictEqual(blocks[0].text, "\n\n \n  \n");
+            assert.strictEqual(blocks[0].text, "\n\n\n \n  \n");
         });
 
         it("should ignore code fences with unspecified info string", () => {
@@ -234,7 +234,7 @@ describe("processor", () => {
             const blocks = processor.preprocess(code);
 
             assert.strictEqual(blocks.length, 1);
-            assert.strictEqual(blocks[0].filename, "0.javascript");
+            assert.strictEqual(blocks[0].filename, "0.js");
         });
 
         it("should find code fences with node info string", () => {
@@ -270,7 +270,7 @@ describe("processor", () => {
             const blocks = processor.preprocess(code);
 
             assert.strictEqual(blocks.length, 1);
-            assert.strictEqual(blocks[0].filename, "0.JavaScript");
+            assert.strictEqual(blocks[0].filename, "0.js");
         });
 
         it("should ignore anything after the first word of the info string", () => {
@@ -398,7 +398,7 @@ describe("processor", () => {
             assert.strictEqual(blocks.length, 2);
             assert.strictEqual(blocks[0].filename, "0.js");
             assert.strictEqual(blocks[0].text, "var answer = 6 * 7;\n");
-            assert.strictEqual(blocks[1].filename, "1.javascript");
+            assert.strictEqual(blocks[1].filename, "1.js");
             assert.strictEqual(blocks[1].text, "console.log(answer);\n");
         });