diff --git a/.eslintrc.js b/.eslintrc.js
new file mode 100644
index 000000000000..44ceb9ec1e54
--- /dev/null
+++ b/.eslintrc.js
@@ -0,0 +1,227 @@
+"use strict";
+const { isCI } = require("ci-info");
+
+module.exports = {
+  root: true,
+  env: {
+    es2020: true,
+    node: true,
+  },
+  extends: ["eslint:recommended", "prettier"],
+  plugins: ["prettier-internal-rules", "import", "regexp", "unicorn"],
+  settings: {
+    "import/internal-regex": "^linguist-languages/",
+  },
+  rules: {
+    "arrow-body-style": ["error", "as-needed"],
+    curly: "error",
+    "dot-notation": "error",
+    eqeqeq: "error",
+    "import/no-extraneous-dependencies": [
+      "error",
+      {
+        devDependencies: ["tests*/**", "scripts/**"],
+      },
+    ],
+    "import/order": "error",
+    "no-console": isCI ? "error" : "off",
+    "no-else-return": [
+      "error",
+      {
+        allowElseIf: false,
+      },
+    ],
+    "no-implicit-coercion": "error",
+    "no-inner-declarations": "error",
+    "no-restricted-syntax": [
+      "error",
+      // `!foo === bar` and `!foo !== bar`
+      'BinaryExpression[operator=/^[!=]==$/] > UnaryExpression.left[operator="!"]',
+    ],
+    "no-unneeded-ternary": "error",
+    "no-useless-return": "error",
+    "no-unused-vars": [
+      "error",
+      {
+        ignoreRestSiblings: true,
+      },
+    ],
+    "no-var": "error",
+    "object-shorthand": "error",
+    "one-var": ["error", "never"],
+    "prefer-arrow-callback": "error",
+    "prefer-const": [
+      "error",
+      {
+        destructuring: "all",
+      },
+    ],
+    "prefer-destructuring": [
+      "error",
+      {
+        VariableDeclarator: {
+          array: false,
+          object: true,
+        },
+        AssignmentExpression: {
+          array: false,
+          object: false,
+        },
+      },
+      {
+        enforceForRenamedProperties: false,
+      },
+    ],
+    "prefer-object-spread": "error",
+    "prefer-rest-params": "error",
+    "prefer-spread": "error",
+    "prettier-internal-rules/jsx-identifier-case": "error",
+    "prettier-internal-rules/require-json-extensions": "error",
+    "prettier-internal-rules/no-identifier-n": "error",
+    quotes: [
+      "error",
+      "double",
+      {
+        avoidEscape: true,
+      },
+    ],
+    strict: "error",
+    "symbol-description": "error",
+    yoda: [
+      "error",
+      "never",
+      {
+        exceptRange: true,
+      },
+    ],
+    "regexp/match-any": [
+      "error",
+      {
+        allows: ["dotAll"],
+      },
+    ],
+    "regexp/no-useless-flag": "error",
+    "unicorn/better-regex": "error",
+    "unicorn/explicit-length-check": "error",
+    "unicorn/new-for-builtins": "error",
+    "unicorn/no-array-for-each": "error",
+    "unicorn/no-array-push-push": "error",
+    "unicorn/no-useless-undefined": "error",
+    "unicorn/prefer-array-flat": [
+      "error",
+      {
+        functions: ["flat", "flatten"],
+      },
+    ],
+    "unicorn/prefer-array-flat-map": "error",
+    "unicorn/prefer-includes": "error",
+    "unicorn/prefer-number-properties": "error",
+    "unicorn/prefer-optional-catch-binding": "error",
+    "unicorn/prefer-regexp-test": "error",
+    "unicorn/prefer-spread": "error",
+    "unicorn/prefer-string-slice": "error",
+  },
+  overrides: [
+    {
+      files: ["scripts/**/*.js", "scripts/**/*.mjs"],
+      rules: {
+        "no-console": "off",
+      },
+    },
+    {
+      files: ["**/*.mjs"],
+      parserOptions: {
+        sourceType: "module",
+      },
+      rules: {
+        "unicorn/prefer-module": "error",
+        "unicorn/prefer-node-protocol": "error",
+      },
+    },
+    {
+      files: [
+        "tests/format/**/jsfmt.spec.js",
+        "tests/config/**/*.js",
+        "tests/integration/**/*.js",
+      ],
+      env: {
+        jest: true,
+      },
+      plugins: ["jest"],
+      rules: {
+        "jest/valid-expect": [
+          "error",
+          {
+            alwaysAwait: true,
+          },
+        ],
+      },
+    },
+    {
+      files: ["tests/**/*.js"],
+      rules: {
+        strict: "off",
+        "unicorn/prefer-array-flat": "off",
+        "unicorn/prefer-array-flat-map": "off",
+      },
+      globals: {
+        run_spec: false,
+      },
+    },
+    {
+      files: ["src/cli/**/*.js"],
+      rules: {
+        "no-restricted-modules": [
+          "error",
+          {
+            patterns: [".."],
+          },
+        ],
+      },
+    },
+    {
+      files: "src/language-js/needs-parens.js",
+      rules: {
+        "prettier-internal-rules/better-parent-property-check-in-needs-parens":
+          "error",
+      },
+    },
+    {
+      files: "src/**/*.js",
+      rules: {
+        "prettier-internal-rules/consistent-negative-index-access": "error",
+        "prettier-internal-rules/flat-ast-path-call": "error",
+        "prettier-internal-rules/no-conflicting-comment-check-flags": "error",
+        "prettier-internal-rules/no-doc-builder-concat": "error",
+        "prettier-internal-rules/no-empty-flat-contents-for-if-break": "error",
+        "prettier-internal-rules/no-unnecessary-ast-path-call": "error",
+        "prettier-internal-rules/prefer-ast-path-each": "error",
+        "prettier-internal-rules/prefer-indent-if-break": "error",
+        "prettier-internal-rules/prefer-is-non-empty-array": "error",
+      },
+    },
+    {
+      files: ["src/language-*/**/*.js"],
+      rules: {
+        "prettier-internal-rules/directly-loc-start-end": "error",
+      },
+    },
+    {
+      files: ["src/language-js/**/*.js"],
+      rules: {
+        "prettier-internal-rules/no-node-comments": [
+          "error",
+          {
+            file: "src/language-js/utils.js",
+            functions: ["hasComment", "getComments"],
+          },
+          "src/language-js/parse-postprocess.js",
+          "src/language-js/parser-babel.js",
+          "src/language-js/parser-meriyah.js",
+          "src/language-js/pragma.js",
+          "src/language-js/parser/json.js",
+        ],
+      },
+    },
+  ],
+};
diff --git a/.eslintrc.yml b/.eslintrc.yml
deleted file mode 100644
index 1e6f74f65c2a..000000000000
--- a/.eslintrc.yml
+++ /dev/null
@@ -1,166 +0,0 @@
-root: true
-env:
-  es2020: true
-  node: true
-extends:
-  - eslint:recommended
-  - prettier
-plugins:
-  - prettier-internal-rules
-  - import
-  - regexp
-  - unicorn
-settings:
-  import/internal-regex: ^linguist-languages/
-rules:
-  arrow-body-style:
-    - error
-    - as-needed
-  curly: error
-  dot-notation: error
-  eqeqeq: error
-  import/no-extraneous-dependencies:
-    - error
-    - devDependencies: ["tests*/**", "scripts/**"]
-  import/order: error
-  no-else-return:
-    - error
-    - allowElseIf: false
-  no-implicit-coercion: error
-  no-inner-declarations: error
-  no-restricted-syntax:
-    - error
-    - 'BinaryExpression[operator=/^[!=]==$/] > UnaryExpression.left[operator="!"]'
-  no-unneeded-ternary: error
-  no-useless-return: error
-  no-unused-vars:
-    - error
-    - ignoreRestSiblings: true
-  no-var: error
-  object-shorthand: error
-  one-var:
-    - error
-    - never
-  prefer-arrow-callback: error
-  prefer-const:
-    - error
-    - destructuring: all
-  prefer-destructuring:
-    - error
-    - VariableDeclarator:
-        array: false
-        object: true
-      AssignmentExpression:
-        array: false
-        object: false
-    - enforceForRenamedProperties: false
-  prefer-object-spread: error
-  prefer-rest-params: error
-  prefer-spread: error
-  prettier-internal-rules/jsx-identifier-case: error
-  prettier-internal-rules/require-json-extensions: error
-  prettier-internal-rules/no-identifier-n: error
-  quotes:
-    - error
-    - double
-    - avoidEscape: true
-  strict: error
-  symbol-description: error
-  yoda:
-    - error
-    - never
-    - exceptRange: true
-  regexp/match-any:
-    - error
-    - allows:
-        - dotAll
-  regexp/no-useless-flag: error
-  unicorn/better-regex: error
-  unicorn/explicit-length-check: error
-  unicorn/new-for-builtins: error
-  unicorn/no-array-for-each: error
-  unicorn/no-array-push-push: error
-  unicorn/no-useless-undefined: error
-  unicorn/prefer-array-flat:
-    - error
-    - functions:
-        - flat
-        - flatten
-  unicorn/prefer-array-flat-map: error
-  unicorn/prefer-includes: error
-  unicorn/prefer-number-properties: error
-  unicorn/prefer-optional-catch-binding: error
-  unicorn/prefer-regexp-test: error
-  unicorn/prefer-spread: error
-  unicorn/prefer-string-slice: error
-overrides:
-  - files:
-      - scripts/**/*.js
-    rules:
-      no-console: off
-  - files:
-      - "**/*.mjs"
-    parserOptions:
-      sourceType: module
-    rules:
-      unicorn/prefer-module: error
-      unicorn/prefer-node-protocol: error
-  - files:
-      - "tests/format/**/jsfmt.spec.js"
-      - "tests/config/**/*.js"
-      - "tests/integration/**/*.js"
-    env:
-      jest: true
-    plugins:
-      - jest
-    rules:
-      jest/valid-expect:
-        - error
-        - alwaysAwait: true
-  - files:
-      - tests/**/*.js
-    rules:
-      strict: off
-      unicorn/prefer-array-flat: off
-      unicorn/prefer-array-flat-map: off
-    globals:
-      run_spec: false
-  - files:
-      - src/cli/**/*.js
-    rules:
-      no-restricted-modules:
-        - error
-        - patterns:
-            - ".."
-  - files: src/language-js/needs-parens.js
-    rules:
-      prettier-internal-rules/better-parent-property-check-in-needs-parens: error
-  - files: src/**/*.js
-    rules:
-      prettier-internal-rules/consistent-negative-index-access: error
-      prettier-internal-rules/flat-ast-path-call: error
-      prettier-internal-rules/no-conflicting-comment-check-flags: error
-      prettier-internal-rules/no-doc-builder-concat: error
-      prettier-internal-rules/no-empty-flat-contents-for-if-break: error
-      prettier-internal-rules/no-unnecessary-ast-path-call: error
-      prettier-internal-rules/prefer-ast-path-each: error
-      prettier-internal-rules/prefer-indent-if-break: error
-      prettier-internal-rules/prefer-is-non-empty-array: error
-  - files:
-      - src/language-*/**/*.js
-    rules:
-      prettier-internal-rules/directly-loc-start-end: error
-  - files:
-      - src/language-js/**/*.js
-    rules:
-      prettier-internal-rules/no-node-comments:
-        - error
-        - file: "src/language-js/utils.js"
-          functions:
-            - hasComment
-            - getComments
-        - "src/language-js/parse-postprocess.js"
-        - "src/language-js/parser-babel.js"
-        - "src/language-js/parser-meriyah.js"
-        - "src/language-js/pragma.js"
-        - "src/language-js/parser/json.js"