More converting to typescript

frontend/eslint.config.js

@@ -1,29 +0,0 @@
-import js from '@eslint/js'
-import globals from 'globals'
-import reactHooks from 'eslint-plugin-react-hooks'
-import reactRefresh from 'eslint-plugin-react-refresh'
-import { defineConfig, globalIgnores } from 'eslint/config'
-
-export default defineConfig([
-  globalIgnores(['dist']),
-  {
-    files: ['**/*.{js,jsx}'],
-    extends: [
-      js.configs.recommended,
-      reactHooks.configs.flat.recommended,
-      reactRefresh.configs.vite,
-    ],
-    languageOptions: {
-      ecmaVersion: 2020,
-      globals: globals.browser,
-      parserOptions: {
-        ecmaVersion: 'latest',
-        ecmaFeatures: { jsx: true },
-        sourceType: 'module',
-      },
-    },
-    rules: {
-      'no-unused-vars': ['error', { varsIgnorePattern: '^[A-Z_]' }],
-    },
-  },
-])

frontend/eslint.config.ts

@@ -0,0 +1,35 @@
+// frontend/eslint.config.ts
+
+import js from '@eslint/js';
+import globals from 'globals';
+import reactHooks from 'eslint-plugin-react-hooks';
+import reactRefresh from 'eslint-plugin-react-refresh';
+import tseslint from 'typescript-eslint';
+
+export default tseslint.config(
+  { ignores: ['dist'] },
+
+  {
+    files: ['**/*.{ts,tsx}'],
+    extends: [
+      js.configs.recommended,
+      ...tseslint.configs.recommended,
+    ],
+    languageOptions: {
+      ecmaVersion: 2020,
+      globals: globals.browser,
+    },
+    plugins: {
+      'react-hooks': reactHooks,
+      'react-refresh': reactRefresh,
+    },
+    rules: {
+      ...reactHooks.configs.recommended.rules,
+      'react-refresh/only-export-components': [
+        'warn',
+        { allowConstantExport: true },
+      ],
+      '@typescript-eslint/no-unused-vars': ['error', { varsIgnorePattern: '^[A-Z_]' }],
+    },
+  }
+);

frontend/global.d.ts

@@ -0,0 +1,3 @@
+// frontend/global.d.ts
+
+declare module '*.css';

frontend/package-lock.json

@@ -18,9 +18,10 @@
         "tailwind-merge": "^3.4.0"
       },
       "devDependencies": {
-        "@eslint/js": "^9.39.1",
+        "@eslint/js": "^9.39.4",
         "@testing-library/jest-dom": "^6.9.1",
         "@testing-library/react": "^16.3.2",
+        "@types/node": "^25.4.0",
         "@types/react": "^19.2.7",
         "@types/react-dom": "^19.2.3",
         "@vitejs/plugin-react": "^5.1.1",
@@ -32,6 +33,7 @@
         "jsdom": "^28.0.0",
         "postcss": "^8.5.6",
         "tailwindcss": "^4.1.18",
+        "typescript-eslint": "^8.57.0",
         "vite": "^7.3.1",
         "vitest": "^4.0.18"
       }
@@ -1066,9 +1068,9 @@
       }
     },
     "node_modules/@eslint/js": {
-      "version": "9.39.2",
+      "version": "9.39.4",
-      "resolved": "https://registry.npmjs.org/@eslint/js/-/js-9.39.2.tgz",
+      "resolved": "https://registry.npmjs.org/@eslint/js/-/js-9.39.4.tgz",
-      "integrity": "sha512-q1mjIoW1VX4IvSocvM/vbTiveKC4k9eLrajNEuSsmjymSDEbpGddtpfOoN7YGAqBK3NG+uqo8ia4PDTt8buCYA==",
+      "integrity": "sha512-nE7DEIchvtiFTwBw4Lfbu59PG+kCofhjsKaCWzxTpt4lfRjRMqG6uMBzKXuEcyXhOHoUp9riAm7/aWYGhXZ9cw==",
       "dev": true,
       "license": "MIT",
       "engines": {
@@ -1973,6 +1975,16 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/node": {
+      "version": "25.4.0",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-25.4.0.tgz",
+      "integrity": "sha512-9wLpoeWuBlcbBpOY3XmzSTG3oscB6xjBEEtn+pYXTfhyXhIxC5FsBer2KTopBlvKEiW9l13po9fq+SJY/5lkhw==",
+      "devOptional": true,
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~7.18.0"
+      }
+    },
     "node_modules/@types/react": {
       "version": "19.2.14",
       "resolved": "https://registry.npmjs.org/@types/react/-/react-19.2.14.tgz",
@@ -1993,6 +2005,301 @@
         "@types/react": "^19.2.0"
       }
     },
+    "node_modules/@typescript-eslint/eslint-plugin": {
+      "version": "8.57.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/eslint-plugin/-/eslint-plugin-8.57.0.tgz",
+      "integrity": "sha512-qeu4rTHR3/IaFORbD16gmjq9+rEs9fGKdX0kF6BKSfi+gCuG3RCKLlSBYzn/bGsY9Tj7KE/DAQStbp8AHJGHEQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@eslint-community/regexpp": "^4.12.2",
+        "@typescript-eslint/scope-manager": "8.57.0",
+        "@typescript-eslint/type-utils": "8.57.0",
+        "@typescript-eslint/utils": "8.57.0",
+        "@typescript-eslint/visitor-keys": "8.57.0",
+        "ignore": "^7.0.5",
+        "natural-compare": "^1.4.0",
+        "ts-api-utils": "^2.4.0"
+      },
+      "engines": {
+        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/typescript-eslint"
+      },
+      "peerDependencies": {
+        "@typescript-eslint/parser": "^8.57.0",
+        "eslint": "^8.57.0 || ^9.0.0 || ^10.0.0",
+        "typescript": ">=4.8.4 <6.0.0"
+      }
+    },
+    "node_modules/@typescript-eslint/eslint-plugin/node_modules/ignore": {
+      "version": "7.0.5",
+      "resolved": "https://registry.npmjs.org/ignore/-/ignore-7.0.5.tgz",
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+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">= 4"
+      }
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+    "node_modules/@typescript-eslint/parser": {
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+        "@typescript-eslint/visitor-keys": "8.57.0",
+        "debug": "^4.4.3"
+      },
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+        "typescript": ">=4.8.4 <6.0.0"
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+        "@typescript-eslint/types": "^8.57.0",
+        "debug": "^4.4.3"
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+        "debug": "^4.4.3",
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+      "license": "ISC",
+      "bin": {
+        "semver": "bin/semver.js"
+      },
+      "engines": {
+        "node": ">=10"
+      }
+    },
+    "node_modules/@typescript-eslint/utils": {
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+      "license": "MIT",
+      "dependencies": {
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+        "@typescript-eslint/scope-manager": "8.57.0",
+        "@typescript-eslint/types": "8.57.0",
+        "@typescript-eslint/typescript-estree": "8.57.0"
+      },
+      "engines": {
+        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/typescript-eslint"
+      },
+      "peerDependencies": {
+        "eslint": "^8.57.0 || ^9.0.0 || ^10.0.0",
+        "typescript": ">=4.8.4 <6.0.0"
+      }
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+      "license": "MIT",
+      "dependencies": {
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+        "eslint-visitor-keys": "^5.0.0"
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+        "url": "https://opencollective.com/typescript-eslint"
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+    "node_modules/@typescript-eslint/visitor-keys/node_modules/eslint-visitor-keys": {
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/eslint-visitor-keys/-/eslint-visitor-keys-5.0.1.tgz",
+      "integrity": "sha512-tD40eHxA35h0PEIZNeIjkHoDR4YjjJp34biM0mDvplBe//mB+IHCqHDGV7pxF+7MklTvighcCPPZC7ynWyjdTA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "engines": {
+        "node": "^20.19.0 || ^22.13.0 || >=24"
+      },
+      "funding": {
+        "url": "https://opencollective.com/eslint"
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+    },
     "node_modules/@vitejs/plugin-react": {
       "version": "5.1.4",
       "resolved": "https://registry.npmjs.org/@vitejs/plugin-react/-/plugin-react-5.1.4.tgz",
@@ -2928,6 +3235,19 @@
         "url": "https://opencollective.com/eslint"
       }
     },
+    "node_modules/eslint/node_modules/@eslint/js": {
+      "version": "9.39.2",
+      "resolved": "https://registry.npmjs.org/@eslint/js/-/js-9.39.2.tgz",
+      "integrity": "sha512-q1mjIoW1VX4IvSocvM/vbTiveKC4k9eLrajNEuSsmjymSDEbpGddtpfOoN7YGAqBK3NG+uqo8ia4PDTt8buCYA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+      },
+      "funding": {
+        "url": "https://eslint.org/donate"
+      }
+    },
     "node_modules/espree": {
       "version": "10.4.0",
       "resolved": "https://registry.npmjs.org/espree/-/espree-10.4.0.tgz",
@@ -4636,6 +4956,19 @@
         "node": ">=20"
       }
     },
+    "node_modules/ts-api-utils": {
+      "version": "2.4.0",
+      "resolved": "https://registry.npmjs.org/ts-api-utils/-/ts-api-utils-2.4.0.tgz",
+      "integrity": "sha512-3TaVTaAv2gTiMB35i3FiGJaRfwb3Pyn/j3m/bfAvGe8FB7CF6u+LMYqYlDh7reQf7UNvoTvdfAqHGmPGOSsPmA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=18.12"
+      },
+      "peerDependencies": {
+        "typescript": ">=4.8.4"
+      }
+    },
     "node_modules/type-check": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.4.0.tgz",
@@ -4649,6 +4982,45 @@
         "node": ">= 0.8.0"
       }
     },
+    "node_modules/typescript": {
+      "version": "5.9.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
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+      "dev": true,
+      "license": "Apache-2.0",
+      "peer": true,
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    },
+    "node_modules/typescript-eslint": {
+      "version": "8.57.0",
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@typescript-eslint/eslint-plugin": "8.57.0",
+        "@typescript-eslint/parser": "8.57.0",
+        "@typescript-eslint/typescript-estree": "8.57.0",
+        "@typescript-eslint/utils": "8.57.0"
+      },
+      "engines": {
+        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/typescript-eslint"
+      },
+      "peerDependencies": {
+        "eslint": "^8.57.0 || ^9.0.0 || ^10.0.0",
+        "typescript": ">=4.8.4 <6.0.0"
+      }
+    },
     "node_modules/undici": {
       "version": "7.21.0",
       "resolved": "https://registry.npmjs.org/undici/-/undici-7.21.0.tgz",
@@ -4659,6 +5031,13 @@
         "node": ">=20.18.1"
       }
     },
+    "node_modules/undici-types": {
+      "version": "7.18.2",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.18.2.tgz",
+      "integrity": "sha512-AsuCzffGHJybSaRrmr5eHr81mwJU3kjw6M+uprWvCXiNeN9SOGwQ3Jn8jb8m3Z6izVgknn1R0FTCEAP2QrLY/w==",
+      "devOptional": true,
+      "license": "MIT"
+    },
     "node_modules/update-browserslist-db": {
       "version": "1.2.3",
       "resolved": "https://registry.npmjs.org/update-browserslist-db/-/update-browserslist-db-1.2.3.tgz",

frontend/package.json

@@ -21,9 +21,10 @@
     "tailwind-merge": "^3.4.0"
   },
   "devDependencies": {
-    "@eslint/js": "^9.39.1",
+    "@eslint/js": "^9.39.4",
     "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^16.3.2",
+    "@types/node": "^25.4.0",
     "@types/react": "^19.2.7",
     "@types/react-dom": "^19.2.3",
     "@vitejs/plugin-react": "^5.1.1",
@@ -35,6 +36,7 @@
     "jsdom": "^28.0.0",
     "postcss": "^8.5.6",
     "tailwindcss": "^4.1.18",
+    "typescript-eslint": "^8.57.0",
     "vite": "^7.3.1",
     "vitest": "^4.0.18"
   }

frontend/src/App.test.tsx

@@ -1,9 +1,10 @@
-// frontend/src/App.test.jsx
+// frontend/src/App.test.tsx
 
 import { render, waitFor } from '@testing-library/react';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 import App from './App';
 
+// Setup mocks
 const localStorageMock = {
     getItem: vi.fn(),
     setItem: vi.fn(),
@@ -11,15 +12,18 @@ const localStorageMock = {
     clear: vi.fn(),
     theme: 'light',
 };
-global.localStorage = localStorageMock;
 
-global.fetch = vi.fn(() =>
+const fetchMock = vi.fn(() =>
     Promise.resolve({
         ok: true,
         json: () => Promise.resolve({}),
     })
 );
 
+// Use Vitest's stubGlobal for type-safe environment mocking
+vi.stubGlobal('localStorage', localStorageMock);
+vi.stubGlobal('fetch', fetchMock);
+
 describe('App Component', () => {
     beforeEach(() => {
         vi.clearAllMocks();
@@ -27,7 +31,6 @@ describe('App Component', () => {
         document.documentElement.style.backgroundColor = '';
     });
 
-    // Notice the "async" keyword added here
     it('renders the App and applies the light theme by default', async () => {
         render(<App />);
 
@@ -38,7 +41,7 @@ describe('App Component', () => {
 
         // 2. Wait for the asynchronous fetch to finish so React doesn't complain
         await waitFor(() => {
-            expect(global.fetch).toHaveBeenCalled();
+            expect(fetchMock).toHaveBeenCalled();
         });
     });
 });

frontend/src/App.tsx

@@ -1,4 +1,4 @@
-// frontend/src/App.jsx
+// frontend/src/App.tsx
 
 import { useEffect, useState } from 'react';
 import { BrowserRouter, Navigate, Route, Routes } from 'react-router-dom';
@@ -8,7 +8,7 @@ import Login from './pages/Login';
 import Tournament from './pages/Tournament';
 
 export default function App() {
-  const [darkMode, setDarkMode] = useState(() => localStorage.theme === 'dark');
+  const [darkMode, setDarkMode] = useState<boolean>(() => localStorage.theme === 'dark');
 
   useEffect(() => {
     const root = window.document.documentElement;

frontend/src/main.jsx

@@ -1,11 +0,0 @@
-// frontend/src/main.jsx
-import { StrictMode } from 'react'
-import { createRoot } from 'react-dom/client'
-import './index.css'
-import App from './App.jsx'
-
-createRoot(document.getElementById('root')).render(
-  <StrictMode>
-    <App />
-  </StrictMode>,
-)

frontend/src/main.tsx

@@ -0,0 +1,12 @@
+// frontend/src/main.tsx
+
+import { StrictMode } from 'react';
+import { createRoot } from 'react-dom/client';
+import App from './App';
+import './index.css';
+
+createRoot(document.getElementById('root')!).render(
+  <StrictMode>
+    <App />
+  </StrictMode>,
+);

frontend/src/vite-env.d.ts

@@ -0,0 +1,3 @@
+// frontend/src/vite-env.d.ts
+
+/// <reference types="vite/client" />

frontend/tsconfig.json

@@ -0,0 +1,38 @@
+{
+    "compilerOptions": {
+        "target": "ES2020",
+        "useDefineForClassFields": true,
+        "lib": [
+            "ES2020",
+            "DOM",
+            "DOM.Iterable"
+        ],
+        "module": "ESNext",
+        "skipLibCheck": true,
+        /* Bundler mode */
+        "moduleResolution": "bundler",
+        "allowImportingTsExtensions": true,
+        "resolveJsonModule": true,
+        "isolatedModules": true,
+        "noEmit": true,
+        "jsx": "react-jsx",
+        /* Linting */
+        "strict": true,
+        "noUnusedLocals": true,
+        "noUnusedParameters": true,
+        "noFallthroughCasesInSwitch": true,
+        /* Path Aliases */
+        "paths": {
+            "@/*": [
+                "./src/*"
+            ]
+        }
+    },
+    "include": [
+        "src",
+        "vite.config.ts"
+    ],
+    "exclude": [
+        "node_modules"
+    ]
+}

frontend/vite.config.ts

@@ -1,15 +1,16 @@
-// frontend/vite.config.js
+// frontend/vite.config.ts
-import tailwindcss from '@tailwindcss/vite'
+
-import react from '@vitejs/plugin-react'
+import tailwindcss from '@tailwindcss/vite';
-import path from 'path'
+import react from '@vitejs/plugin-react';
-import { defineConfig } from 'vite'
+import path from 'path';
+import { defineConfig } from 'vitest/config';
 
 export default defineConfig({
   plugins: [react(), tailwindcss()],
   test: {
     globals: true,
     environment: 'jsdom',
-    setupFiles: './vitest.setup.js',
+    setupFiles: './vitest.setup.ts',
     css: true,
   },
   resolve: {
@@ -17,4 +18,4 @@ export default defineConfig({
       '@': path.resolve(__dirname, './src'),
     },
   },
-})
+});