tsconfig.json

{
  "compilerOptions": {
    // Enable latest features
    "lib": [
      "ESNext",
      "DOM",
      "DOM.Iterable"
    ],
    "target": "ESNext",
    "module": "Preserve",
    "moduleDetection": "force",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "jsx": "react-jsx",
    "allowJs": true,
    // Bundler mode
    "moduleResolution": "bundler",
    "allowImportingTsExtensions": true,
    "verbatimModuleSyntax": true,
    // Best practices
    "strict": true,
    "skipLibCheck": true,
    "noFallthroughCasesInSwitch": true,
    // Some stricter flags (disabled by default)
    "noUnusedLocals": false,
    "noImplicitAny": true,
    "noImplicitOverride": true,
    "noImplicitThis": true,
    "noUnusedParameters": false,
    "noPropertyAccessFromIndexSignature": false,
    // Output declarations
    "declaration": true,
    "declarationDir": "lib",
    "emitDeclarationOnly": true,
    "stripInternal": true
  },
  "include": [
    "src"
  ]
}