Update to ESLint 9's "flat" configuration file format.

.eslintrc.json

@@ -1,140 +0,0 @@
-{
-  "env": {
-    "node": true,
-    "es2021": true
-  },
-  "extends": [
-    "eslint:all",
-    "plugin:jsdoc/recommended",
-    "plugin:n/recommended",
-    "plugin:regexp/recommended",
-    "plugin:unicorn/all"
-  ],
-  "ignorePatterns": [
-    "demo/markdown-it.min.js",
-    "demo/markdownlint-browser.js",
-    "demo/markdownlint-browser.min.js",
-    "demo/micromark-browser.js",
-    "demo/micromark-html-browser.js",
-    "example/typescript/type-check.js",
-    "micromark/micromark.cjs",
-    "micromark/micromark.dev.cjs",
-    "micromark/micromark-browser.js",
-    "micromark/micromark-browser.dev.js",
-    "test-repos/"
-  ],
-  "overrides": [
-    {
-      "files": [
-        "demo/*.js"
-      ],
-      "env": {
-        "browser": true
-      },
-      "rules": {
-        "jsdoc/require-jsdoc": "off",
-        "unicorn/prefer-query-selector": "off",
-        "unicorn/prefer-add-event-listener": "off",
-        "no-console": "off",
-        "no-invalid-this": "off",
-        "no-shadow": "off",
-        "no-var": "off"
-      }
-    },
-    {
-      "files": [
-        "example/*.js"
-      ],
-      "rules": {
-        "n/no-extraneous-require": "off",
-        "n/no-missing-require": "off",
-        "no-console": "off",
-        "no-invalid-this": "off",
-        "no-shadow": "off",
-        "object-property-newline": "off"
-      }
-    },
-    {
-      "files": [
-        "test/rules/**/*.js"
-      ],
-      "rules": {
-        "jsdoc/valid-types": "off"
-      }
-    },
-    {
-      "files": [
-        "**/*.mjs"
-      ],
-      "parserOptions": {
-        "ecmaVersion": 2022,
-        "sourceType": "module"
-      }
-    }
-  ],
-  "parserOptions": {
-    "ecmaVersion": 2021,
-    "sourceType": "script"
-  },
-  "plugins": [
-    "jsdoc",
-    "n",
-    "regexp",
-    "unicorn"
-  ],
-  "reportUnusedDisableDirectives": true,
-  "rules": {
-    "capitalized-comments": "off",
-    "complexity": "off",
-    "func-style": "off",
-    "id-length": "off",
-    "jsdoc/tag-lines": ["error", "never", {"startLines":1}],
-    "logical-assignment-operators": "off",
-    "max-depth": "off",
-    "max-lines-per-function": "off",
-    "max-lines": "off",
-    "max-params": "off",
-    "max-statements": "off",
-    "multiline-comment-style": ["error", "separate-lines"],
-    "no-empty-function": "off",
-    "no-implicit-coercion": "off",
-    "no-magic-numbers": "off",
-    "no-param-reassign": "off",
-    "no-plusplus": "off",
-    "no-ternary": "off",
-    "no-undefined": "off",
-    "object-shorthand": "off",
-    "one-var": "off",
-    "prefer-arrow-callback": "off",
-    "prefer-destructuring": "off",
-    "prefer-named-capture-group": "off",
-    "prefer-template": "off",
-    "regexp/no-super-linear-backtracking": "off",
-    "require-unicode-regexp": "off",
-    "sort-imports": "off",
-    "sort-keys": "off",
-    "unicorn/better-regex": "off",
-    "unicorn/consistent-function-scoping": "off",
-    "unicorn/filename-case": "off",
-    "unicorn/no-array-callback-reference": "off",
-    "unicorn/no-keyword-prefix": "off",
-    "unicorn/no-new-array": "off",
-    "unicorn/no-null": "off",
-    "unicorn/no-useless-undefined": "off",
-    "unicorn/prefer-at": "off",
-    "unicorn/prefer-module": "off",
-    "unicorn/prefer-string-replace-all": "off",
-    "unicorn/prefer-string-slice": "off",
-    "unicorn/prefer-switch": "off",
-    "unicorn/prevent-abbreviations": "off",
-    "unicorn/switch-case-braces": ["error", "avoid"],
-    "vars-on-top": "off"
-  },
-  "settings": {
-    "jsdoc": {
-      "preferredTypes": {
-        "object": "Object"
-      }
-    }
-  }
-}

.npmignore

@@ -1,5 +1,4 @@
 .eslintignore
-.eslintrc.json
 .github
 .markdownlint.json
 .npmrc
@@ -8,6 +7,7 @@ coverage
 demo/*
 !demo/markdownlint-browser.js
 doc-build
+eslint.config.mjs
 example
 micromark
 npm-debug.log

demo/default.js

@@ -267,8 +267,7 @@
       if (hashPrefix === decodedHash.substring(0, hashPrefix.length)) {
         markdown.value = decodedHash.substring(hashPrefix.length);
       }
-      /* eslint-disable-next-line unicorn/prefer-optional-catch-binding */
+    } catch {
-    } catch (error) {
       // Invalid
     }
   }
@@ -277,8 +276,7 @@
   try {
     /* eslint-disable-next-line no-new */
     new URL("https://example.com/");
-    /* eslint-disable-next-line unicorn/prefer-optional-catch-binding */
+  } catch {
-  } catch (error) {
     markdown.value = [
       "# Sorry",
       "",

demo/markdownlint-browser.js

@@ -1723,7 +1723,7 @@ function validateRuleList(ruleList, synchronous) {
   const allIds = {};
   for (const [ index, rule ] of ruleList.entries()) {
     const customIndex = index - rules.length;
-    // eslint-disable-next-line no-inner-declarations, jsdoc/require-jsdoc
+    // eslint-disable-next-line jsdoc/require-jsdoc
     function newError(property, value) {
       return new Error(
         `Property '${property}' of custom rule at index ${customIndex} is incorrect: '${value}'.`);

eslint.config.mjs

@@ -0,0 +1,138 @@
+import js from "@eslint/js";
+import eslintPluginJsdoc from "eslint-plugin-jsdoc";
+import eslintPluginNode from "eslint-plugin-n";
+import eslintPluginRegexp from "eslint-plugin-regexp"
+import eslintPluginUnicorn from "eslint-plugin-unicorn";
+
+export default [
+  js.configs.all,
+  eslintPluginJsdoc.configs['flat/recommended'],
+  eslintPluginNode.configs["flat/recommended"],
+  eslintPluginRegexp.configs["flat/recommended"],
+  eslintPluginUnicorn.configs["flat/all"],
+  {
+    "ignores": [
+      "demo/markdown-it.min.js",
+      "demo/markdownlint-browser.js",
+      "demo/markdownlint-browser.min.js",
+      "demo/micromark-browser.js",
+      "demo/micromark-html-browser.js",
+      "example/typescript/type-check.js",
+      "micromark/micromark.cjs",
+      "micromark/micromark.dev.cjs",
+      "micromark/micromark-browser.js",
+      "micromark/micromark-browser.dev.js",
+      "test-repos/**"
+    ]
+  },
+  {
+    "languageOptions": {
+      "sourceType": "commonjs",
+    },
+    "linterOptions": {
+      "reportUnusedDisableDirectives": true
+    },
+    "rules": {
+      "capitalized-comments": "off",
+      "complexity": "off",
+      "func-style": "off",
+      "id-length": "off",
+      "jsdoc/tag-lines": [ "error", "never", { "startLines":1 } ],
+      "logical-assignment-operators": "off",
+      "max-depth": "off",
+      "max-lines-per-function": "off",
+      "max-lines": "off",
+      "max-params": "off",
+      "max-statements": "off",
+      "multiline-comment-style": [ "error", "separate-lines" ],
+      "no-empty-function": "off",
+      "no-implicit-coercion": "off",
+      "no-magic-numbers": "off",
+      "no-param-reassign": "off",
+      "no-plusplus": "off",
+      "no-ternary": "off",
+      "no-undefined": "off",
+      "no-useless-assignment": "off",
+      "object-shorthand": "off",
+      "one-var": "off",
+      "prefer-arrow-callback": "off",
+      "prefer-destructuring": "off",
+      "prefer-named-capture-group": "off",
+      "prefer-template": "off",
+      "regexp/no-super-linear-backtracking": "off",
+      "require-unicode-regexp": "off",
+      "sort-imports": "off",
+      "sort-keys": "off",
+      "unicorn/better-regex": "off",
+      "unicorn/consistent-function-scoping": "off",
+      "unicorn/filename-case": "off",
+      "unicorn/no-array-callback-reference": "off",
+      "unicorn/no-keyword-prefix": "off",
+      "unicorn/no-new-array": "off",
+      "unicorn/no-null": "off",
+      "unicorn/no-useless-undefined": "off",
+      "unicorn/prefer-at": "off",
+      "unicorn/prefer-module": "off",
+      "unicorn/prefer-string-replace-all": "off",
+      "unicorn/prefer-string-slice": "off",
+      "unicorn/prefer-switch": "off",
+      "unicorn/prevent-abbreviations": "off",
+      "unicorn/switch-case-braces": [ "error", "avoid" ],
+      "vars-on-top": "off"
+    },
+    "settings": {
+      "jsdoc": {
+        "preferredTypes": {
+          "object": "Object"
+        }
+      }
+    }
+  },
+  {
+    "files": [
+      "**/*.mjs"
+    ],
+    "languageOptions": {
+      "sourceType": "module"
+    }
+  },
+  {
+    "files": [
+      "demo/*.js"
+    ],
+    "languageOptions": {
+      "globals": {
+        "alert": "readonly",
+        "document": "readonly",
+        "navigator": "readonly",
+        "window": "readonly"
+      }
+    },
+    "rules": {
+      "jsdoc/require-jsdoc": "off",
+      "no-invalid-this": "off",
+      "no-shadow": "off",
+      "no-var": "off",
+      "unicorn/prefer-query-selector": "off"
+    }
+  },
+  {
+    "files": [
+      "example/*.js"
+    ],
+    "rules": {
+      "n/no-missing-require": "off",
+      "no-console": "off",
+      "no-invalid-this": "off",
+      "no-shadow": "off"
+    }
+  },
+  {
+    "files": [
+      "test/rules/**/*.js"
+    ],
+    "rules": {
+      "jsdoc/valid-types": "off"
+    }
+  }
+];

lib/markdownlint.js

@@ -32,7 +32,7 @@ function validateRuleList(ruleList, synchronous) {
   const allIds = {};
   for (const [ index, rule ] of ruleList.entries()) {
     const customIndex = index - rules.length;
-    // eslint-disable-next-line no-inner-declarations, jsdoc/require-jsdoc
+    // eslint-disable-next-line jsdoc/require-jsdoc
     function newError(property, value) {
       return new Error(
         `Property '${property}' of custom rule at index ${customIndex} is incorrect: '${value}'.`);

package.json

@@ -49,7 +49,7 @@
     "docker-npm-install": "docker run --rm --tty --name npm-install --volume $PWD:/home/workdir --workdir /home/workdir --user node node:latest npm install",
     "docker-npm-run-upgrade": "docker run --rm --tty --name npm-run-upgrade --volume $PWD:/home/workdir --workdir /home/workdir --user node node:latest npm run upgrade",
     "install-micromark": "cd micromark && npm install",
-    "lint": "eslint --ext .js,.cjs,.mjs --max-warnings 0 .",
+    "lint": "eslint --max-warnings 0",
     "lint-test-repos": "ava --timeout=10m test/markdownlint-test-repos-*.js",
     "serial-config-docs": "npm run build-config && npm run build-docs",
     "serial-declaration-demo": "npm run build-declaration && npm-run-all --continue-on-error --parallel build-demo test-declaration",
@@ -69,6 +69,7 @@
     "markdownlint-micromark": "0.1.10"
   },
   "devDependencies": {
+    "@eslint/js": "9.1.1",
     "ajv": "8.12.0",
     "ava": "6.1.2",
     "c8": "9.1.0",

test/markdownlint-test-custom-rules.js

@@ -1598,22 +1598,12 @@ test("customRulesLintJavaScript", (t) => new Promise((resolve) => {
     t.falsy(err);
     const expected = {
       "test/lint-javascript.md": [
-        {
-          "lineNumber": 10,
-          "ruleNames": [ "lint-javascript" ],
-          "ruleDescription": "Rule that lints JavaScript code",
-          "ruleInformation": null,
-          "errorDetail": "Unexpected var, use let or const instead.",
-          "errorContext": "var x = 0;",
-          "errorRange": null,
-          "fixInfo": null
-        },
         {
           "lineNumber": 12,
           "ruleNames": [ "lint-javascript" ],
           "ruleDescription": "Rule that lints JavaScript code",
           "ruleInformation": null,
-          "errorDetail": "Unexpected console statement.",
+          "errorDetail": "'console' is not defined.",
           "errorContext": "console.log(x);",
           "errorRange": null,
           "fixInfo": null

test/rules/lint-javascript.js

@@ -2,54 +2,31 @@
 
 "use strict";
 
+const js = require("@eslint/js");
 const { filterTokens } = require("../../helpers");
 const eslint = require("eslint");
-const eslintInstance = new eslint.ESLint();
 const linter = new eslint.Linter();
 const languageJavaScript = /js|javascript/i;
 
-/**
- * Remove references to rules from eslint-plugin-jsdoc.
- *
- * @param {Object} config ESLint configuration object.
- * @returns {Object} ESLint configuration object.
- */
-function cleanJsdocRulesFromEslintConfig(config) {
-  const cleanedConfig = { ...config };
-  for (const rule in config.rules) {
-    if (/^(?:jsdoc|n|regexp|unicorn)\//.test(rule)) {
-      delete cleanedConfig.rules[rule];
-    }
-  }
-  return cleanedConfig;
-}
-
 /** @type import("../../lib/markdownlint").Rule */
 module.exports = {
   "names": [ "lint-javascript" ],
   "description": "Rule that lints JavaScript code",
   "tags": [ "test", "lint", "javascript" ],
   "parser": "markdownit",
-  "asynchronous": true,
   "function": (params, onError) => {
     filterTokens(params, "fence", (fence) => {
       if (languageJavaScript.test(fence.info)) {
-        return eslintInstance.calculateConfigForFile(params.name)
+        const results = linter.verify(fence.content, js.configs.recommended);
-          .then((config) => {
+        for (const result of results) {
-            config = cleanJsdocRulesFromEslintConfig(config);
+          const lineNumber = fence.lineNumber + result.line;
-            const results = linter.verify(fence.content, config);
+          onError({
-            for (const result of results) {
+            "lineNumber": lineNumber,
-              // @ts-ignore
+            "detail": result.message,
-              const lineNumber = fence.lineNumber + result.line;
+            "context": params.lines[lineNumber - 1]
-              onError({
-                "lineNumber": lineNumber,
-                "detail": result.message,
-                "context": params.lines[lineNumber - 1]
-              });
-            }
           });
+        }
       }
-      return Promise.resolve();
     });
     // Unsupported:
     //   filterTokens("code_block"), language unknown