Fix: use blocksCache instead of single blocks instance (fixes #181) (#…

…183)

* Fix: use blocksCache instead of single blocks instance

pass through lint messages from other plugins

* refactor: use Map and delete map after postprocess

remove unnecessary mdx example

* Chore: add test case for blocksCache

* Revert: downgrade remark-parse and unified

* chore: remove unnecessary fallback check

* refactor: simplify return statement

examples/typescript/README.md

@@ -1,4 +1,4 @@
-# React Example
+# TypeScript Example
 
 The `@typescript-eslint` parser and the `recommended` config's rules will work in `ts` code blocks. However, [type-aware rules](https://github.com/typescript-eslint/typescript-eslint/blob/master/docs/getting-started/linting/TYPED_LINTING.md) will not work because the code blocks are not part of a compilable `tsconfig.json` project.
 

lib/processor.js

@@ -36,9 +36,9 @@ const SUPPORTS_AUTOFIX = true;
 const markdown = unified().use(remarkParse);
 
 /**
- * @type {Block[]}
+ * @type {Map<string, Block[]>}
  */
-let blocks = [];
+const blocksCache = new Map();
 
 /**
  * Performs a depth-first traversal of the Markdown AST.
@@ -235,10 +235,14 @@ function getBlockRangeMap(text, node, comments) {
 /**
  * Extracts lintable code blocks from Markdown text.
  * @param {string} text The text of the file.
+ * @param {string} filename The filename of the file
  * @returns {Array<{ filename: string, text: string }>} Source code blocks to lint.
  */
-function preprocess(text) {
+function preprocess(text, filename) {
     const ast = markdown.parse(text);
+    const blocks = [];
+
+    blocksCache.set(filename, blocks);
 
     /**
      * During the depth-first traversal, keep track of any sequences of HTML
@@ -250,7 +254,6 @@ function preprocess(text) {
      */
     let htmlComments = [];
 
-    blocks = [];
     traverse(ast, {
         "*"() {
             htmlComments = [];
@@ -370,9 +373,14 @@ 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 {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.get(filename);
+
+    blocksCache.delete(filename);
+
     return [].concat(...messages.map((group, i) => {
         const adjust = adjustBlock(blocks[i]);
 

tests/lib/plugin.js

@@ -11,20 +11,23 @@ const CLIEngine = require("eslint").CLIEngine;
 const path = require("path");
 const plugin = require("../..");
 
+/**
+ * @typedef {import('eslint/lib/cli-engine/cli-engine').CLIEngineOptions} CLIEngineOptions
+ */
+
 /**
  * Helper function which creates CLIEngine instance with enabled/disabled autofix feature.
  * @param {string} fixtureConfigName ESLint JSON config fixture filename.
- * @param {boolean} [isAutofixEnabled=false] Whether to enable autofix feature.
+ * @param {CLIEngineOptions} [options={}] Whether to enable autofix feature.
  * @returns {CLIEngine} CLIEngine instance to execute in tests.
  */
-function initCLI(fixtureConfigName, isAutofixEnabled) {
-    const fix = isAutofixEnabled || false;
+function initCLI(fixtureConfigName, options = {}) {
     const cli = new CLIEngine({
         cwd: path.resolve(__dirname, "../fixtures/"),
-        fix,
         ignore: false,
         useEslintrc: false,
-        configFile: path.resolve(__dirname, "../fixtures/", fixtureConfigName)
+        configFile: path.resolve(__dirname, "../fixtures/", fixtureConfigName),
+        ...options
     });
 
     cli.addPlugin("markdown", plugin);
@@ -242,6 +245,45 @@ describe("plugin", () => {
         assert.strictEqual(report.results[0].messages[4].column, 2);
     });
 
+    // https://github.com/eslint/eslint-plugin-markdown/issues/181
+    it("should work when called on nested code blocks in the same file", () => {
+
+        /*
+          * As of this writing, the nested code block, though it uses the same
+          * Markdown processor, must use a different extension or ESLint will not
+          * re-apply the processor on the nested code block. To work around that,
+          * a file named `test.md` contains a nested `markdown` code block in
+          * this test.
+          *
+          * https://github.com/eslint/eslint/pull/14227/files#r602802758
+          */
+        const code = [
+            "<!-- test.md -->",
+            "",
+            "````markdown",
+            "<!-- test.md/0_0.markdown -->",
+            "",
+            "This test only repros if the MD files have a different number of lines before code blocks.",
+            "",
+            "```js",
+            "// test.md/0_0.markdown/0_0.js",
+            "console.log('single quotes')",
+            "```",
+            "````"
+        ].join("\n");
+        const recursiveCli = initCLI("eslintrc.json", {
+            extensions: [".js", ".markdown", ".md"]
+        });
+        const report = recursiveCli.executeOnText(code, "test.md");
+
+        assert.strictEqual(report.results.length, 1);
+        assert.strictEqual(report.results[0].messages.length, 2);
+        assert.strictEqual(report.results[0].messages[0].message, "Unexpected console statement.");
+        assert.strictEqual(report.results[0].messages[0].line, 10);
+        assert.strictEqual(report.results[0].messages[1].message, "Strings must use doublequote.");
+        assert.strictEqual(report.results[0].messages[1].line, 10);
+    });
+
     describe("configuration comments", () => {
 
         it("apply only to the code block immediately following", () => {
@@ -282,7 +324,7 @@ describe("plugin", () => {
     describe("should fix code", () => {
 
         before(() => {
-            cli = initCLI("eslintrc.json", true);
+            cli = initCLI("eslintrc.json", { fix: true });
         });
 
         it("in the simplest case", () => {