feat: Support ESLint v7 (#190)

* deps: update ESLint v7

BREAKING CHANGE: Support minimum ESLint version is v7.

* test: use ESLint class instead of CLIEngine

* deps: update ESLint version in devDependencies and peerDependencies

BREAKING CHANGE: drop ESLint v6 support

* deps: update typescript-eslint version to v3

BREAKING CHANGE: Enable new rules in @typescript-eslint/recommended

- @typescript-eslint/no-extra-non-null-assertion
- @typescript-eslint/no-extra-semi
- @typescript-eslint/no-non-null-asserted-optional-chain
- ⚠️ @typescript-eslint/prefer-as-const

* chore: revert changes in fixture

* test: update snapshot for a disabled rule

* deps: update eslint and typescript-eslint

* deps: update typescript-eslint/* to v3.3.0

* deps: update ESLint and typescript-eslint/*

configs/typescript.js

@@ -1,29 +1,21 @@
 module.exports = {
   parser: '@typescript-eslint/parser',
   plugins: ['@typescript-eslint'],
-  extends: [
-    'plugin:@typescript-eslint/eslint-recommended',
-    'plugin:@typescript-eslint/recommended',
-    'prettier/@typescript-eslint'
-  ],
+  extends: ['plugin:@typescript-eslint/recommended', 'prettier/@typescript-eslint'],
   rules: {
-    '@typescript-eslint/array-type': ['error', {default: 'array-simple'}],
+    '@typescript-eslint/array-type': ['error', { default: 'array-simple' }],
     'no-useless-constructor': 'off',
-    '@typescript-eslint/type-annotation-spacing': 'warn',
     '@typescript-eslint/unified-signatures': 'warn',
-    '@typescript-eslint/ban-ts-ignore': 'off',
-    '@typescript-eslint/camelcase': 'off',
-    '@typescript-eslint/explicit-function-return-type': 'off',
+    '@typescript-eslint/ban-ts-comment': 'off',
     '@typescript-eslint/explicit-member-accessibility': 'off',
-    '@typescript-eslint/interface-name-prefix': 'off',
+    '@typescript-eslint/explicit-module-boundary-types': 'off',
     '@typescript-eslint/no-empty-interface': 'off',
     '@typescript-eslint/no-explicit-any': 'off',
     '@typescript-eslint/no-inferrable-types': 'off',
     '@typescript-eslint/no-non-null-assertion': 'off',
     '@typescript-eslint/no-object-literal-type-assertion': 'off',
     '@typescript-eslint/no-triple-slash-reference': 'off',
     '@typescript-eslint/no-unused-vars': 'off',
-    '@typescript-eslint/no-use-before-define': 'off',
     '@typescript-eslint/no-var-requires': 'off',
     '@typescript-eslint/prefer-interface': 'off',
     '@typescript-eslint/prefer-namespace-keyword': 'off',

package.json

@@ -27,22 +27,22 @@
   },
   "devDependencies": {
     "@types/react": "^16.9.38",
-    "eslint": "^6.8.0",
+    "eslint": "^7.3.1",
     "jest": "^26.0.1",
     "prettier": "^2.0.5",
     "react": "^16.13.1",
     "standard-version": "^8.0.0",
     "typescript": "^3.9.5"
   },
   "peerDependencies": {
-    "eslint": "^6.4.0",
+    "eslint": "^7.0.0",
     "prettier": "^1.17.0 || ^2.0.0",
     "react": "^16.8.6",
     "typescript": "^3.4.5"
   },
   "dependencies": {
-    "@typescript-eslint/eslint-plugin": "^2.34.0",
-    "@typescript-eslint/parser": "^2.34.0",
+    "@typescript-eslint/eslint-plugin": "^3.4.0",
+    "@typescript-eslint/parser": "^3.4.0",
     "eslint-config-prettier": "^6.11.0",
     "eslint-plugin-jsx-a11y": "^6.3.1",
     "eslint-plugin-prettier": "^3.1.4",

test/__snapshots__/run.test.js.snap

@@ -19,7 +19,6 @@ Object {
   },
   "sum.ts": Object {
     "errors": Array [
-      "no-import-assign",
       "default-param-last",
       "prefer-regex-literals",
       "no-shadow",

test/lib/runLint.js

@@ -1,19 +1,19 @@
 'use strict'
 
-const CLIEngine = require('eslint').CLIEngine
+const { ESLint } = require('eslint')
 const path = require('path')
 
-const runLintWithFixtures = (configFile, target) => {
-  const cli = new CLIEngine({
-    configFile,
+const runLintWithFixtures = async (configFile, target) => {
+  const eslint = new ESLint({
+    overrideConfigFile: configFile,
     ignore: false,
     useEslintrc: false,
     extensions: ['.js', '.jsx', '.ts', '.tsx'],
   })
-  const lintResult = cli.executeOnFiles([target])
+  const lintResult = await eslint.lintFiles([target])
   // console.log(JSON.stringify(lintResult, null, 2))
 
-  return lintResult.results.reduce((results, { filePath, messages }) => {
+  return lintResult.reduce((results, { filePath, messages }) => {
     return Object.assign(results, {
       [path.basename(filePath)]: messages.reduce(
         (resultPerFile, { severity, ruleId }) => {

test/run.test.js

@@ -1,8 +1,8 @@
 const runLint = require('./lib/runLint')
 
 describe('fixtures', () => {
-  it('should match the snapshot', () => {
-    const result = runLint('./index.js', './test/fixtures')
+  it('should match the snapshot', async () => {
+    const result = await runLint('./index.js', './test/fixtures')
     expect(result).toMatchSnapshot()
   })
 })