tsconfig.json

{
  "compilerOptions": {
    // Enable latest features
    "lib": ["ESNext", "DOM", "DOM.Iterable", "DOM.AsyncIterable"],
    "target": "ESNext",
    "module": "ESNext",
    "moduleDetection": "force",
    // "jsx": "react-jsx",
    "jsxFactory": "h",
    "jsxImportSource": "preact",
    "allowJs": true,

    // preact
    // see https://preactjs.com/guide/v10/getting-started
    "skipLibCheck": true,
    "baseUrl": "./",
    "paths": {
      "react": ["./node_modules/preact/compat/"],
      "react/jsx-runtime": ["./node_modules/preact/jsx-runtime"],
      "react-dom": ["./node_modules/preact/compat/"],
      "react-dom/*": ["./node_modules/preact/compat/*"]
    },

    // Bundler mode
    "moduleResolution": "bundler",
    "allowImportingTsExtensions": true,
    "verbatimModuleSyntax": true,
    "noEmit": true,

    // Best practices
    "strict": true,
    "noFallthroughCasesInSwitch": true,

    // Some stricter flags
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noPropertyAccessFromIndexSignature": true
  }
}