Eslint config migration (#756)

* init eslint config

* fix common problems and remove rules requiring React to be in scope (we're React version > 17)

* relax use of explicit any for eslint for migration purposes

* fix additional miscelaneous errors

* add prettier and jsxA11y eslint plugins to our new config

* remove old eslint configs from package.json

* remove old unused dev dependencies include ts-jest (we don't use jest anymore)

* migrate vitest to version > 2

* enable strict and stylistic typescript-eslint configs

.pre-commit-config.yaml

@@ -38,10 +38,11 @@ repos:
           - python
         pass_filenames: false
   - repo: https://github.com/pre-commit/mirrors-eslint
-    rev: 'v8.56.0'
+    rev: 'v9.8.0'
     hooks:
       - id: eslint
-        files: \.[jt]sx?$
+        files: ^client/.*\.[jt]sx?$
+        args: [-c=client/eslint.config.js]
         types: [file]
   - repo: https://github.com/pre-commit/mirrors-prettier
     rev: 'v3.1.0'

client/.gitignore

@@ -18,3 +18,5 @@ npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
 tsconfig.tsbuildinfo
+.next
+next-env.d.ts

client/eslint.config.js

@@ -0,0 +1,62 @@
+import reactPlugin from 'eslint-plugin-react'; // https://github.com/jsx-eslint/eslint-plugin-react?tab=readme-ov-file#configuration
+import globals from 'globals';
+import pluginJs from '@eslint/js';
+import tsEslint from 'typescript-eslint';
+import jsxA11y from 'eslint-plugin-jsx-a11y';
+import eslintPluginPrettierRecommended from 'eslint-plugin-prettier/recommended';
+
+export default [
+  // ToDo: eslint-plugin-react-hooks does not yet support eslint > 9 and this config
+  pluginJs.configs.recommended,
+  jsxA11y.flatConfigs.recommended,
+  // ...tseslint.configs.recommended, // recommended config is overridden by strict/stylistic
+  ...tsEslint.configs.strict,
+  ...tsEslint.configs.stylistic,
+  eslintPluginPrettierRecommended,
+  {
+    name: 'ignore-outputs',
+    ignores: ['**/build/', '**/dist/', '**/node_modules/', '**/.next/'],
+  },
+  {
+    name: 'react',
+    files: ['**/*.{js,mjs,cjs,ts,jsx,tsx}'],
+    ...reactPlugin.configs.flat.recommended,
+    languageOptions: {
+      ...reactPlugin.configs.flat.recommended.languageOptions,
+      globals: globals.browser,
+      parserOptions: {
+        ecmaFeatures: { jsx: true },
+      },
+    },
+    rules: {
+      'react/react-in-jsx-scope': 0,
+      'react/jsx-uses-react': 0,
+    },
+  },
+  {
+    name: 'ts-migration-relax',
+    files: ['**/*.{ts,tsx}'],
+    rules: {
+      '@typescript-eslint/no-explicit-any': 'warn',
+      '@typescript-eslint/no-empty-interface': 'off',
+      '@typescript-eslint/no-empty-function': 'off',
+    },
+  },
+  {
+    name: 'ts-unused-vars',
+    rules: {
+      '@typescript-eslint/no-unused-vars': [
+        'error',
+        {
+          args: 'all',
+          argsIgnorePattern: '^_',
+          caughtErrors: 'all',
+          caughtErrorsIgnorePattern: '^_',
+          destructuredArrayIgnorePattern: '^_',
+          varsIgnorePattern: '^_',
+          // ignoreRestSiblings: true, - if you want to ignore unused rest siblings
+        },
+      ],
+    },
+  },
+];