Eslint: upgrade to version 8.0.0

package.json

@@ -17,7 +17,8 @@
     "@babel/eslint-parser": "^7.16.5",
     "babel-jest": "^27.4.5",
     "babel-loader": "^8.2.3",
-    "eslint": "^7.32.0",
+    "eslint": "^8.5.0",
+    "eslint-formatter-codeframe": "^7.32.1",
     "flow-bin": "^0.168.0",
     "glob": "^7.2.0",
     "jest": "^27.4.5",

src/eslint-config-adeira/CHANGELOG.md

@@ -2,7 +2,8 @@
 
 **Breaking changes ahead!**
 
-- New rules enabled: `fb-flow/use-indexed-access-type` ([more info](https://flow.org/en/docs/types/indexed-access/)) and `ft-flow/enforce-suppression-code` (warnings or errors in strict mode).
+- Eslint version 8 is now required (visit https://eslint.org/blog/2021/10/eslint-v8.0.0-released and other related blog posts for more info).
+- New rules enabled: `fb-flow/use-indexed-access-type` ([more info](https://flow.org/en/docs/types/indexed-access/)), `ft-flow/enforce-suppression-code` and `no-unused-private-class-members`.
 - Many rules that were showing warnings in normal mode but errors in strict mode were converted to normal errors (so there is no difference between normal and strict mode). The best way how to migrate is to temporarily switch to the strict mode and address all the errors before upgrading to this major version.
 - Switched from [`eslint-plugin-flowtype`](https://github.com/gajus/eslint-plugin-flowtype/tree/449cb99f1b6d3bbbb66f5be55f497667f5b2cb31) to [`eslint-plugin-ft-flow`](https://github.com/flow-typed/eslint-plugin-ft-flow/tree/820e631ce491cdf45821744d4e29f348cf776392) which contains the same set of rules but should be more up to date and maintained. We are going to enable additional rules later. There is a possible minor breaking change (with very simple fix) when suppressing the rules manually, for example:
 

src/eslint-config-adeira/__tests__/__fixtures__/valid-eslint-examples/node/process-exit-as-throw.js

@@ -7,6 +7,11 @@ class Bar {}
 // Normally, Eslint would complain because of `consistent-return` error, however,
 // rule `node/process-exit-as-throw` makes sure this is not the case.
 // See: https://github.com/mysticatea/eslint-plugin-node/blob/master/docs/rules/process-exit-as-throw.md
+
+// TODO: the following `consistent-return` error is incorrect and should be removed once the following
+//       issue is resolved: https://github.com/mysticatea/eslint-plugin-node/issues/301. We decided to
+//       accept the low risk for now to ease migration to Eslint 8.
+// eslint-disable-next-line consistent-return
 export function foo(a: boolean): ?Bar {
   if (a) {
     return new Bar();

src/eslint-config-adeira/__tests__/__snapshots__/index.test.js.snap

@@ -711,6 +711,7 @@ Object {
     "no-unsafe-optional-chaining": 2,
     "no-unused-expressions": 0,
     "no-unused-labels": 1,
+    "no-unused-private-class-members": 2,
     "no-unused-vars": Array [
       2,
       Object {
@@ -763,6 +764,7 @@ Object {
     "prefer-exponentiation-operator": 2,
     "prefer-named-capture-group": 2,
     "prefer-numeric-literals": 0,
+    "prefer-object-has-own": 0,
     "prefer-object-spread": 2,
     "prefer-promise-reject-errors": 1,
     "prefer-regex-literals": 2,

src/eslint-config-adeira/__tests__/__snapshots__/presets.test.js.snap

@@ -416,6 +416,7 @@ Object {
     "no-unsafe-optional-chaining": 2,
     "no-unused-expressions": 0,
     "no-unused-labels": 1,
+    "no-unused-private-class-members": 2,
     "no-unused-vars": Array [
       2,
       Object {
@@ -459,6 +460,7 @@ Object {
     "prefer-exponentiation-operator": 2,
     "prefer-named-capture-group": 2,
     "prefer-numeric-literals": 0,
+    "prefer-object-has-own": 0,
     "prefer-object-spread": 2,
     "prefer-promise-reject-errors": 1,
     "prefer-regex-literals": 2,

src/eslint-config-adeira/package.json

@@ -42,6 +42,6 @@
     "snapshot-diff": "^0.9.0"
   },
   "peerDependencies": {
-    "eslint": ">=7.24.0 <8.0.0"
+    "eslint": ">=8.0.0"
   }
 }

src/eslint-config-adeira/src/presets/base.js

@@ -55,6 +55,7 @@ module.exports = ({
     'no-unsafe-finally': ERROR,
     'no-unsafe-negation': ERROR,
     'no-unsafe-optional-chaining': ERROR,
+    'no-unused-private-class-members': ERROR,
     'require-atomic-updates': ERROR,
     'use-isnan': [ERROR, { enforceForSwitchCase: true }],
     'valid-jsdoc': OFF,
@@ -268,6 +269,7 @@ module.exports = ({
     'prefer-const': [ERROR, { destructuring: 'all' }],
     'prefer-destructuring': OFF,
     'prefer-numeric-literals': OFF,
+    'prefer-object-has-own': OFF, // TODO: NEXT_VERSION_ERROR (?) (https://eslint.org/docs/rules/prefer-object-has-own)
     'prefer-rest-params': WARN,
     'prefer-spread': WARN,
     'prefer-template': ERROR,

src/eslint-config-adeira/src/presets/flowtype.js

@@ -11,7 +11,9 @@ import type { EslintConfig } from '../EslintConfig.flow';
 module.exports = ({
   plugins: ['eslint-plugin-ft-flow', 'eslint-plugin-fb-flow'],
   rules: {
-    // flowtype (https://github.com/gajus/eslint-plugin-flowtype)
+    // Flow:
+    //  - https://github.com/flow-typed/eslint-plugin-ft-flow
+    //  - https://github.com/gajus/eslint-plugin-flowtype
     'ft-flow/array-style-complex-type': OFF,
     'ft-flow/array-style-simple-type': OFF,
     'ft-flow/arrow-parens': OFF,

src/eslint-fixtures-tester/package.json

@@ -18,10 +18,10 @@
     "@adeira/js": "^2.1.1",
     "@babel/eslint-parser": "^7.16.5",
     "@babel/runtime": "^7.16.5",
-    "eslint": "^7.32.0",
+    "eslint": "^8.5.0",
     "jest-docblock": "^27.4.0"
   },
   "peerDependencies": {
-    "eslint": "^7.32.0"
+    "eslint": "^8.5.0"
   }
 }

src/eslint-plugin-adeira/package.json

@@ -22,7 +22,7 @@
     "@adeira/eslint-fixtures-tester": "0.1.0",
     "@adeira/flow-types-eslint": "0.0.0",
     "@babel/eslint-parser": "^7.16.5",
-    "eslint": "^7.32.0"
+    "eslint": "^8.5.0"
   },
   "peerDependencies": {
     "graphql": "^14.0.0 || ^15.0.0"

src/eslint-plugin-sx/package.json

@@ -26,11 +26,11 @@
     "@adeira/flow-types-eslint": "0.0.0",
     "@babel/code-frame": "^7.16.0",
     "@babel/eslint-parser": "^7.16.5",
-    "eslint": "^7.32.0",
+    "eslint": "^8.5.0",
     "react": "^17.0.2"
   },
   "peerDependencies": {
     "@adeira/sx": "^0.28.0",
-    "eslint": "^7.32.0"
+    "eslint": "^8.5.0"
   }
 }

src/signed-source/src/__tests__/SignedSource.test.js

@@ -5,11 +5,11 @@ import os from 'os';
 import SignedSource from '../SignedSource';
 
 test('signFile', () => {
-  expect(SignedSource.signFile(`# ${SignedSource.getSigningToken()}\ntest 1`)).toEqual(
+  expect(SignedSource.signFile(`# ${SignedSource.getSigningToken()}\ntest 1`)).toBe(
     `# @generated SignedSource<<d9b7b52f54978f54b84a0fd48145e470>>${os.EOL}test 1`,
   );
 
-  expect(SignedSource.signFile(`# ${SignedSource.getSigningToken()}\ntest 2`)).toEqual(
+  expect(SignedSource.signFile(`# ${SignedSource.getSigningToken()}\ntest 2`)).toBe(
     `# @generated SignedSource<<4c0c1ae4f5863c72731b2f543e830fd5>>${os.EOL}test 2`,
   );
 
@@ -18,7 +18,7 @@ test('signFile', () => {
     SignedSource.signFile(
       `# @generated SignedSource<<eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee>>\nalready signed test`,
     ),
-  ).toEqual(`# @generated SignedSource<<54e8ffafff15a19f858d95c9a13d5b1d>>\nalready signed test`);
+  ).toBe(`# @generated SignedSource<<54e8ffafff15a19f858d95c9a13d5b1d>>\nalready signed test`);
 
   expect(() =>
     SignedSource.signFile(`signature missing, no sign token`),