[eslint-plugin] Remove eslint-v8 testing (#84721)

ESLint plugin defaults to flat config, and we also dropped the built-in
lint check at #83136, so we can
sunset the deprecated ESLint v8 testing.

Author: devjiwonchoi

package.json

@@ -200,7 +200,6 @@
     "eslint-plugin-mdx": "3.1.5",
     "eslint-plugin-react": "7.35.0",
     "eslint-plugin-react-hooks": "0.0.0-experimental-3025aa39-20251007",
-    "eslint-v8": "npm:eslint@^8.57.0",
     "event-stream": "4.0.1",
     "execa": "2.0.3",
     "expect": "29.7.0",

pnpm-lock.yaml

@@ -1,5 +1,4 @@
-import { RuleTester as ESLintTesterV8 } from 'eslint-v8'
-import { RuleTester as ESLintTesterV9 } from 'eslint'
+import { RuleTester } from 'eslint'
 import { rules } from '@next/eslint-plugin-next'
 
 const NextESLintRule = rules['google-font-display']
@@ -164,18 +163,7 @@ const tests = {
 }
 
 describe('google-font-display', () => {
-  new ESLintTesterV8({
-    parserOptions: {
-      ecmaVersion: 2020,
-      sourceType: 'module',
-      ecmaFeatures: {
-        modules: true,
-        jsx: true,
-      },
-    },
-  }).run('eslint-v8', NextESLintRule, tests)
-
-  new ESLintTesterV9({
+  new RuleTester({
     languageOptions: {
       ecmaVersion: 2020,
       sourceType: 'module',
@@ -186,5 +174,5 @@ describe('google-font-display', () => {
         },
       },
     },
-  }).run('eslint-v9', NextESLintRule, tests)
+  }).run('eslint', NextESLintRule, tests)
 })

test/unit/eslint-plugin-next/google-font-display.test.ts

@@ -1,5 +1,4 @@
-import { RuleTester as ESLintTesterV8 } from 'eslint-v8'
-import { RuleTester as ESLintTesterV9 } from 'eslint'
+import { RuleTester } from 'eslint'
 import { rules } from '@next/eslint-plugin-next'
 
 const NextESLintRule = rules['google-font-preconnect']
@@ -59,18 +58,7 @@ const tests = {
 }
 
 describe('google-font-preconnect', () => {
-  new ESLintTesterV8({
-    parserOptions: {
-      ecmaVersion: 2020,
-      sourceType: 'module',
-      ecmaFeatures: {
-        modules: true,
-        jsx: true,
-      },
-    },
-  }).run('eslint-v8', NextESLintRule, tests)
-
-  new ESLintTesterV9({
+  new RuleTester({
     languageOptions: {
       ecmaVersion: 2020,
       sourceType: 'module',
@@ -81,5 +69,5 @@ describe('google-font-preconnect', () => {
         },
       },
     },
-  }).run('eslint-v9', NextESLintRule, tests)
+  }).run('eslint', NextESLintRule, tests)
 })

test/unit/eslint-plugin-next/google-font-preconnect.test.ts

@@ -1,5 +1,4 @@
-import { RuleTester as ESLintTesterV8 } from 'eslint-v8'
-import { RuleTester as ESLintTesterV9 } from 'eslint'
+import { RuleTester } from 'eslint'
 import { rules } from '@next/eslint-plugin-next'
 
 const NextESLintRule = rules['inline-script-id']
@@ -179,18 +178,7 @@ const tests = {
 }
 
 describe('inline-script-id', () => {
-  new ESLintTesterV8({
-    parserOptions: {
-      ecmaVersion: 2018,
-      sourceType: 'module',
-      ecmaFeatures: {
-        modules: true,
-        jsx: true,
-      },
-    },
-  }).run('eslint-v8', NextESLintRule, tests)
-
-  new ESLintTesterV9({
+  new RuleTester({
     languageOptions: {
       ecmaVersion: 2018,
       sourceType: 'module',
@@ -201,5 +189,5 @@ describe('inline-script-id', () => {
         },
       },
     },
-  }).run('eslint-v9', NextESLintRule, tests)
+  }).run('eslint', NextESLintRule, tests)
 })

test/unit/eslint-plugin-next/inline-script-id.test.ts

@@ -1,5 +1,4 @@
-import { RuleTester as ESLintTesterV8 } from 'eslint-v8'
-import { RuleTester as ESLintTesterV9 } from 'eslint'
+import { RuleTester } from 'eslint'
 import { rules } from '@next/eslint-plugin-next'
 
 const NextESLintRule = rules['next-script-for-ga']
@@ -232,18 +231,7 @@ const tests = {
 }
 
 describe('next-script-for-ga', () => {
-  new ESLintTesterV8({
-    parserOptions: {
-      ecmaVersion: 2018,
-      sourceType: 'module',
-      ecmaFeatures: {
-        modules: true,
-        jsx: true,
-      },
-    },
-  }).run('eslint-v8', NextESLintRule, tests)
-
-  new ESLintTesterV9({
+  new RuleTester({
     languageOptions: {
       ecmaVersion: 2018,
       sourceType: 'module',
@@ -254,5 +242,5 @@ describe('next-script-for-ga', () => {
         },
       },
     },
-  }).run('eslint-v9', NextESLintRule, tests)
+  }).run('eslint', NextESLintRule, tests)
 })

test/unit/eslint-plugin-next/next-script-for-ga.test.ts

@@ -1,5 +1,4 @@
-import { RuleTester as ESLintTesterV8 } from 'eslint-v8'
-import { RuleTester as ESLintTesterV9 } from 'eslint'
+import { RuleTester } from 'eslint'
 import { rules } from '@next/eslint-plugin-next'
 
 const NextESLintRule = rules['no-assign-module-variable']
@@ -34,18 +33,7 @@ const tests = {
 }
 
 describe('no-assign-module-variable', () => {
-  new ESLintTesterV8({
-    parserOptions: {
-      ecmaVersion: 2018,
-      sourceType: 'module',
-      ecmaFeatures: {
-        modules: true,
-        jsx: true,
-      },
-    },
-  }).run('eslint-v8', NextESLintRule, tests)
-
-  new ESLintTesterV9({
+  new RuleTester({
     languageOptions: {
       ecmaVersion: 2018,
       sourceType: 'module',
@@ -56,5 +44,5 @@ describe('no-assign-module-variable', () => {
         },
       },
     },
-  }).run('eslint-v9', NextESLintRule, tests)
+  }).run('eslint', NextESLintRule, tests)
 })