deps: update eslint to v9

commons/.eslintrc.cjs

@@ -1,30 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-module.exports = {
-    "parser": "@typescript-eslint/parser",
-    "parserOptions": {
-        "project": [
-            "./tsconfig.test.json"
-        ]
-    },
-    "plugins": [
-        "@typescript-eslint",
-        "prettier"
-    ],
-    "extends": [
-        "eslint:recommended",
-        "plugin:@typescript-eslint/eslint-recommended",
-        "plugin:@typescript-eslint/recommended-requiring-type-checking",
-        "plugin:@typescript-eslint/recommended",
-        "prettier"
-    ],
-    "rules": {
-        "prettier/prettier": ["error",
-            require('./.prettierrc.json')
-        ]
-    }
-}

commons/eslint.config.mjs

@@ -0,0 +1,51 @@
+import { defineConfig } from 'eslint/config'
+import typescriptEslint from '@typescript-eslint/eslint-plugin'
+import prettier from 'eslint-plugin-prettier'
+import tsParser from '@typescript-eslint/parser'
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
+import js from '@eslint/js'
+import { FlatCompat } from '@eslint/eslintrc'
+import prettierConfig from './.prettierrc.json' with { type: 'json' }
+import vitest from '@vitest/eslint-plugin'
+
+const __filename = fileURLToPath(import.meta.url)
+const __dirname = path.dirname(__filename)
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all,
+})
+
+export default defineConfig([
+  {
+    extends: compat.extends(
+      'eslint:recommended',
+      'plugin:@typescript-eslint/eslint-recommended',
+      'plugin:@typescript-eslint/recommended-requiring-type-checking',
+      'plugin:@typescript-eslint/recommended',
+      'prettier',
+    ),
+
+    plugins: {
+      '@typescript-eslint': typescriptEslint,
+      prettier,
+      vitest,
+    },
+
+    languageOptions: {
+      parser: tsParser,
+      ecmaVersion: 5,
+      sourceType: 'script',
+
+      parserOptions: {
+        project: ['./tsconfig.test.json'],
+      },
+    },
+
+    rules: {
+      'prettier/prettier': ['error', prettierConfig],
+      ...vitest.configs.recommended.rules,
+    },
+  },
+])

commons/package.json

@@ -11,7 +11,7 @@
     "test:ci": "vitest --run",
     "prepublish": "rm -rf dist && yarn lint && yarn build && yarn test",
     "lint": "eslint src --ext .ts",
-    "lint:fix": "eslint --fix --ext .ts src"
+    "lint:fix": "eslint src --fix --ext .ts"
   },
   "type": "module",
   "source": "src/index.ts",
@@ -52,16 +52,18 @@
     "zod": "3.24.2"
   },
   "devDependencies": {
+    "@eslint/eslintrc": "3.3.1",
+    "@eslint/js": "9.25.1",
     "@mrdrogdrog/optional": "1.2.1",
     "@types/js-yaml": "4.0.9",
     "@types/ws": "8.5.12",
-    "@typescript-eslint/eslint-plugin": "8.14.0",
+    "@vitest/eslint-plugin": "1.1.43",
-    "@typescript-eslint/parser": "8.14.0",
+    "eslint": "9.25.1",
-    "eslint": "8.57.1",
+    "eslint-config-prettier": "10.1.2",
-    "eslint-config-prettier": "9.1.0",
+    "eslint-plugin-prettier": "5.2.6",
-    "eslint-plugin-prettier": "5.2.3",
     "prettier": "3.3.3",
     "typescript": "5.6.3",
+    "typescript-eslint": "8.31.0",
     "vitest": "3.1.2"
   },
   "packageManager": "yarn@4.5.3"

frontend/.eslintrc.js

@@ -1,61 +0,0 @@
-/**
- * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: CC0-1.0
- **/
-module.exports = {
-  "root": true,
-  "parserOptions": {
-    "tsconfigRootDir": ".",
-    "project": [
-      "./tsconfig.json"
-    ]
-  },
-  "rules": {
-    "prettier/prettier": ["error",
-      require('./.prettierrc.json')
-    ],
-    "no-use-before-define": "off",
-    "no-debugger": "warn",
-    "default-param-last": "off",
-    "@typescript-eslint/consistent-type-imports": [
-      "error",
-      {
-        "prefer": "type-imports",
-        "disallowTypeAnnotations": false
-      }
-    ],
-    "jest/no-disabled-tests": "warn",
-    "jest/no-focused-tests": "error",
-    "jest/no-identical-title": "error",
-    "jest/prefer-to-have-length": "warn",
-    "jest/valid-expect": "error"
-  },
-  "env": {
-    "jest": true,
-    "jest/globals": true
-  },
-  "plugins": [
-    "@typescript-eslint",
-    "testing-library",
-    "jest",
-    "prettier"
-  ],
-  "extends": [
-    "next/core-web-vitals",
-    "eslint:recommended",
-    "plugin:@typescript-eslint/eslint-recommended",
-    "plugin:@typescript-eslint/recommended",
-    "plugin:@typescript-eslint/recommended-requiring-type-checking",
-    "prettier"
-  ],
-  "overrides": [
-    {
-      "files": [
-        "**/__tests__/**/*.[jt]s?(x)",
-        "**/?(*.)+(spec|test).[jt]s?(x)"
-      ],
-      "extends": ["plugin:testing-library/react"]
-    }
-  ]
-}

frontend/eslint.config.mjs

@@ -0,0 +1,74 @@
+import { defineConfig } from "eslint/config";
+import typescriptEslint from "@typescript-eslint/eslint-plugin";
+import testingLibrary from "eslint-plugin-testing-library";
+import jest from "eslint-plugin-jest";
+import prettier from "eslint-plugin-prettier";
+import globals from "globals";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import js from "@eslint/js";
+import { FlatCompat } from "@eslint/eslintrc";
+import prettierConfig from "./.prettierrc.json" with {type: "json"}
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+    baseDirectory: __dirname,
+    recommendedConfig: js.configs.recommended,
+    allConfig: js.configs.all
+});
+
+export default defineConfig([{
+    extends: compat.extends(
+        "next/core-web-vitals",
+        "eslint:recommended",
+        "plugin:@typescript-eslint/eslint-recommended",
+        "plugin:@typescript-eslint/recommended",
+        "plugin:@typescript-eslint/recommended-requiring-type-checking",
+        "prettier",
+    ),
+
+    plugins: {
+        "@typescript-eslint": typescriptEslint,
+        "testing-library": testingLibrary,
+        jest,
+        prettier,
+    },
+
+    languageOptions: {
+        globals: {
+            ...globals.jest,
+            ...jest.environments.globals.globals,
+        },
+
+        ecmaVersion: 5,
+        sourceType: "script",
+
+        parserOptions: {
+            tsconfigRootDir: ".",
+            project: ["./tsconfig.json"],
+        },
+    },
+
+    rules: {
+        "prettier/prettier": ["error", prettierConfig],
+
+        "no-use-before-define": "off",
+        "no-debugger": "warn",
+        "default-param-last": "off",
+
+        "@typescript-eslint/consistent-type-imports": ["error", {
+            prefer: "type-imports",
+            disallowTypeAnnotations: false,
+        }],
+
+        "jest/no-disabled-tests": "warn",
+        "jest/no-focused-tests": "error",
+        "jest/no-identical-title": "error",
+        "jest/prefer-to-have-length": "warn",
+        "jest/valid-expect": "error",
+    },
+}, {
+    files: ["**/__tests__/**/*.[jt]s?(x)", "**/?(*.)+(spec|test).[jt]s?(x)"],
+    extends: compat.extends("plugin:testing-library/react"),
+}]);

frontend/package.json

@@ -119,6 +119,8 @@
     "yjs": "13.6.23"
   },
   "devDependencies": {
+    "@eslint/eslintrc": "3.3.1",
+    "@eslint/js": "9.25.1",
     "@next/bundle-analyzer": "15.3.1",
     "@testing-library/cypress": "10.0.3",
     "@testing-library/dom": "10.4.0",
@@ -139,23 +141,21 @@
     "@types/react": "19.1.2",
     "@types/react-dom": "19.1.2",
     "@types/ws": "8.5.12",
-    "@typescript-eslint/eslint-plugin": "8.14.0",
-    "@typescript-eslint/parser": "8.14.0",
     "csstype": "3.1.3",
     "cypress": "13.17.0",
     "cypress-commands": "3.0.0",
     "cypress-fill-command": "1.0.2",
     "dotenv-cli": "7.4.4",
-    "eslint": "8.57.1",
+    "eslint": "9.25.1",
     "eslint-config-next": "15.3.1",
-    "eslint-config-prettier": "9.1.0",
+    "eslint-config-prettier": "10.1.2",
     "eslint-plugin-chai-friendly": "1.0.1",
-    "eslint-plugin-cypress": "4.1.0",
+    "eslint-plugin-cypress": "4.3.0",
-    "eslint-plugin-jest": "28.9.0",
+    "eslint-plugin-jest": "28.11.0",
-    "eslint-plugin-n": "17.13.2",
+    "eslint-plugin-n": "17.17.0",
-    "eslint-plugin-prettier": "5.2.3",
+    "eslint-plugin-prettier": "5.2.6",
-    "eslint-plugin-promise": "7.1.0",
+    "eslint-plugin-promise": "7.2.1",
-    "eslint-plugin-testing-library": "6.4.0",
+    "eslint-plugin-testing-library": "7.1.1",
     "jest": "29.7.0",
     "jest-environment-jsdom": "29.7.0",
     "prettier": "3.3.3",
@@ -164,6 +164,7 @@
     "ts-mockery": "1.2.0",
     "ts-node": "11.0.0-beta.1",
     "typescript": "5.6.3",
+    "typescript-eslint": "8.31.0",
     "user-agent-data-types": "0.4.2"
   },
   "packageManager": "yarn@4.5.3",

frontend/src/components/markdown-renderer/extensions/link-replacer/anchor-node-preprocessor.ts

@@ -22,7 +22,6 @@ export class AnchorNodePreprocessor extends TravelerNodeProcessor {
 
     const url = node.attribs.href.trim()
 
-    // eslint-disable-next-line no-script-url
     if (url.startsWith('data:') || url.startsWith('javascript:') || url.startsWith('vbscript:')) {
       delete node.attribs.href
       return

frontend/src/extensions/external-lib-app-extensions/vimeo/vimeo-frame.tsx

@@ -9,8 +9,6 @@ import React, { useCallback } from 'react'
 import { Vimeo as IconVimeo } from 'react-bootstrap-icons'
 
 interface VimeoApiResponse {
-  // Vimeo uses strange names for their fields. ESLint doesn't like that.
-  // eslint-disable-next-line camelcase
   thumbnail_large?: string
 }
 

html-to-react/.eslintrc.cjs

@@ -1,30 +0,0 @@
-/*
- * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
- *
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-module.exports = {
-    "parser": "@typescript-eslint/parser",
-    "parserOptions": {
-        "project": [
-            "./tsconfig.test.json"
-        ]
-    },
-    "plugins": [
-        "@typescript-eslint",
-        "prettier"
-    ],
-    "extends": [
-        "eslint:recommended",
-        "plugin:@typescript-eslint/eslint-recommended",
-        "plugin:@typescript-eslint/recommended-requiring-type-checking",
-        "plugin:@typescript-eslint/recommended",
-        "prettier"
-    ],
-    "rules": {
-        "prettier/prettier": ["error",
-            require('./.prettierrc.json')
-        ],
-    }
-}

html-to-react/eslint.config.mjs

@@ -0,0 +1,52 @@
+import { defineConfig } from 'eslint/config'
+import typescriptEslint from '@typescript-eslint/eslint-plugin'
+import prettier from 'eslint-plugin-prettier'
+import tsParser from '@typescript-eslint/parser'
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
+import js from '@eslint/js'
+import { FlatCompat } from '@eslint/eslintrc'
+import prettierConfig from './.prettierrc.json' with { type: 'json' }
+import vitest from '@vitest/eslint-plugin'
+
+const __filename = fileURLToPath(import.meta.url)
+const __dirname = path.dirname(__filename)
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all
+})
+
+export default defineConfig([
+  {
+    extends: compat.extends(
+      'eslint:recommended',
+      'plugin:@typescript-eslint/eslint-recommended',
+      'plugin:@typescript-eslint/recommended-requiring-type-checking',
+      'plugin:@typescript-eslint/recommended',
+      'prettier'
+    ),
+
+    plugins: {
+      '@typescript-eslint': typescriptEslint,
+      prettier,
+      vitest
+    },
+
+    languageOptions: {
+      parser: tsParser,
+      ecmaVersion: 5,
+      sourceType: 'script',
+
+      parserOptions: {
+        project: ['./tsconfig.test.json']
+      }
+    },
+
+    rules: {
+      'prettier/prettier': ['error', prettierConfig],
+
+      ...vitest.configs.recommended.rules
+    }
+  }
+])

html-to-react/package.json

@@ -50,15 +50,15 @@
   "devDependencies": {
     "@types/react": "18.3.11",
     "@types/react-dom": "18.3.1",
-    "@typescript-eslint/eslint-plugin": "8.14.0",
+    "@vitest/eslint-plugin": "1.1.43",
-    "@typescript-eslint/parser": "8.14.0",
+    "eslint": "9.25.1",
-    "eslint": "8.57.1",
+    "eslint-config-prettier": "10.1.2",
-    "eslint-config-prettier": "9.1.0",
+    "eslint-plugin-prettier": "5.2.6",
-    "eslint-plugin-prettier": "5.2.3",
     "prettier": "3.3.3",
     "react": "18.3.1",
     "react-dom": "18.3.1",
     "typescript": "5.6.3",
+    "typescript-eslint": "8.31.0",
     "vitest": "3.1.2"
   },
   "dependencies": {

markdown-it-plugins/eslint.config.mjs

@@ -0,0 +1,51 @@
+import { defineConfig } from 'eslint/config'
+import typescriptEslint from '@typescript-eslint/eslint-plugin'
+import prettier from 'eslint-plugin-prettier'
+import tsParser from '@typescript-eslint/parser'
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
+import js from '@eslint/js'
+import { FlatCompat } from '@eslint/eslintrc'
+import prettierConfig from './.prettierrc.json' with { type: 'json' }
+import vitest from '@vitest/eslint-plugin'
+
+const __filename = fileURLToPath(import.meta.url)
+const __dirname = path.dirname(__filename)
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all
+})
+
+export default defineConfig([
+  {
+    extends: compat.extends(
+      'eslint:recommended',
+      'plugin:@typescript-eslint/eslint-recommended',
+      'plugin:@typescript-eslint/recommended-requiring-type-checking',
+      'plugin:@typescript-eslint/recommended',
+      'prettier'
+    ),
+
+    plugins: {
+      '@typescript-eslint': typescriptEslint,
+      prettier,
+      vitest
+    },
+
+    languageOptions: {
+      parser: tsParser,
+      ecmaVersion: 5,
+      sourceType: 'script',
+
+      parserOptions: {
+        project: ['./tsconfig.test.json']
+      }
+    },
+
+    rules: {
+      'prettier/prettier': ['error', prettierConfig],
+      ...vitest.configs.recommended.rules
+    }
+  }
+])

markdown-it-plugins/package.json

@@ -90,7 +90,7 @@
     "test:ci": "vitest --run",
     "prepublish": "rm -rf dist && yarn lint && yarn build && yarn test",
     "lint": "eslint src --ext .ts",
-    "lint:fix": "eslint --fix --ext .ts src"
+    "lint:fix": "eslint src --ext .ts --fix"
   },
   "keywords": [
     "markdown",
@@ -108,15 +108,16 @@
     "html-entities": "2.5.2"
   },
   "devDependencies": {
+    "@eslint/eslintrc": "3.3.1",
+    "@eslint/js": "9.25.1",
     "@types/markdown-it": "13.0.8",
-    "@typescript-eslint/eslint-plugin": "8.14.0",
+    "@vitest/eslint-plugin": "1.1.43",
-    "@typescript-eslint/parser": "8.14.0",
+    "eslint-config-prettier": "10.1.2",
-    "eslint": "8.57.1",
+    "eslint-plugin-prettier": "5.2.6",
-    "eslint-config-prettier": "9.1.0",
-    "eslint-plugin-prettier": "5.2.3",
     "markdown-it": "13.0.2",
     "prettier": "3.3.3",
     "typescript": "5.6.3",
+    "typescript-eslint": "8.31.0",
     "vitest": "3.1.2"
   },
   "repository": {