feat: add support for eslint 8 (#353)

package.json

@@ -11,7 +11,7 @@
   ],
   "scripts": {
     "build": "run-p build:*",
-    "build:r": "r -f esm,es2015",
+    "build:r": "r -f es2015",
     "build:ts": "tsc -b",
     "clean": "rimraf packages/*/{lib,*.tsbuildinfo} node_modules/@1stg/eslint-config/node_modules",
     "lint": "run-p lint:*",
@@ -30,7 +30,7 @@
     "@types/eslint-plugin-markdown": "^2.0.0",
     "@types/jest": "^27.0.2",
     "@types/node": "^16.10.9",
-    "@types/react": "^17.0.29",
+    "@types/react": "^17.0.30",
     "@types/unist": "^2.0.6",
     "lerna": "^4.0.0",
     "npm-run-all": "^4.1.5",
@@ -44,6 +44,12 @@
     "yarn-deduplicate": "^3.1.0"
   },
   "resolutions": {
+    "@typescript-eslint/eslint-plugin": "^5.0.0",
+    "@typescript-eslint/eslint-plugin-tslint": "^5.0.0",
+    "@typescript-eslint/experimental-utils": "^5.0.0",
+    "@typescript-eslint/parser": "^5.0.0",
+    "eslint": "^8.0.1",
+    "eslint-plugin-unicorn": "^37.0.0",
     "prettier": "^2.4.1"
   },
   "commitlint": {
@@ -63,6 +69,7 @@
       "eslint/lib/linter/linter"
     ],
     "moduleNameMapper": {
+      "^eslint/use-at-your-own-risk$": "<rootDir>/node_modules/eslint/lib/unsupported-api.js",
       "^eslint-mdx$": "<rootDir>/packages/eslint-mdx/src",
       "^eslint-plugin-mdx$": "<rootDir>/packages/eslint-plugin-mdx/src"
     },

packages/eslint-mdx/package.json

@@ -13,9 +13,8 @@
   "engines": {
     "node": ">=10.0.0"
   },
-  "main": "lib",
-  "module": "lib/esm",
-  "es2015": "lib/es2015",
+  "main": "lib/index.js",
+  "module": "lib/index.es2015.mjs",
   "types": "lib",
   "files": [
     "lib",

packages/eslint-plugin-mdx/package.json

@@ -13,9 +13,8 @@
   "engines": {
     "node": ">=10.0.0"
   },
-  "main": "lib",
-  "module": "lib/esm",
-  "es2015": "lib/es2015",
+  "main": "lib/index.js",
+  "module": "lib/index.es2015.mjs",
   "types": "lib",
   "files": [
     "lib",

packages/eslint-plugin-mdx/src/helpers.ts

@@ -1,3 +1,5 @@
+import type { Rule } from 'eslint'
+
 export const getGlobals = <
   T extends Record<string, unknown> | string[],
   G extends Record<string, boolean>,
@@ -18,3 +20,27 @@ export const getGlobals = <
     // eslint-disable-next-line @typescript-eslint/prefer-reduce-type-parameter
     initialGlobals as R,
   )
+
+const PRIVATE_API_VERSION = 8
+
+export const getBuiltinRule = (ruleId: string) => {
+  // TODO: Remove this when we drop support for ESLint < 8
+  // eslint-disable-next-line @typescript-eslint/no-require-imports, @typescript-eslint/no-var-requires
+  const { version: eslintVersion } = require('eslint/package.json') as {
+    version: string
+  }
+
+  const majorVersion = Number.parseInt(eslintVersion.split('.')[0], 10)
+
+  /* istanbul ignore next */
+  if (majorVersion < PRIVATE_API_VERSION) {
+    // eslint-disable-next-line @typescript-eslint/no-require-imports, @typescript-eslint/no-var-requires
+    return require(`eslint/lib/rules/${ruleId}`) as Rule.RuleModule
+  }
+
+  // prettier-ignore
+  return (
+    // eslint-disable-next-line @typescript-eslint/consistent-type-imports, @typescript-eslint/no-require-imports, @typescript-eslint/no-var-requires
+    require('eslint/use-at-your-own-risk') as typeof import('eslint/use-at-your-own-risk')
+  ).builtinRules.get(ruleId)
+}

packages/eslint-plugin-mdx/src/rules/no-unused-expressions.ts

@@ -2,10 +2,13 @@
 
 import type { Rule } from 'eslint'
 import { isJsxNode } from 'eslint-mdx'
-import esLintNoUnusedExpressions from 'eslint/lib/rules/no-unused-expressions'
+
+import { getBuiltinRule } from '../helpers'
 
 import type { ExpressionStatementWithParent } from './types'
 
+const esLintNoUnusedExpressions = getBuiltinRule('no-unused-expressions')
+
 export const noUnusedExpressions: Rule.RuleModule = {
   ...esLintNoUnusedExpressions,
   create(context) {

packages/eslint-plugin-mdx/typings.d.ts

@@ -4,3 +4,9 @@ declare module 'remark-mdx' {
   const mdx: unified.Attacher
   export = mdx
 }
+
+declare module 'eslint/use-at-your-own-risk' {
+  import type { Rule } from 'eslint'
+
+  export const builtinRules: Map<string, Rule.RuleModule>
+}

test/__snapshots__/fixtures.test.ts.snap

@@ -172,12 +172,14 @@ Array [
 exports[`fixtures should match all snapshots: comments.mdx 1`] = `
 Array [
   Object {
-    "column": 2,
-    "line": 1,
-    "message": "Unused eslint-disable directive (no problems were reported from 'no-console').",
-    "nodeType": null,
-    "ruleId": null,
-    "severity": 2,
+    "column": 1,
+    "endColumn": 8,
+    "endLine": 9,
+    "line": 9,
+    "message": "Don’t use multiple top level headings (1:1)",
+    "nodeType": "Program",
+    "ruleId": "remark-lint-no-multiple-toplevel-headings",
+    "severity": 1,
   },
 ]
 `;

test/fixtures/comments.mdx

@@ -1 +1,5 @@
-<!-- eslint-disable-next-line no-console -- Here's a description about why this configuration is necessary. -->
+# Header
+<!-- eslint-disable mdx/remark -- Here's a description about why this configuration is necessary. -->
+# Header
+<!-- eslint-enable mdx/remark -->
+# Title