tsconfig.json

{
  // Change this to match your project
  "include": ["./src/*.mjs"],
  "compilerOptions": {
    "outDir": "types",
    "lib": ["es2020"],
    // Tells TypeScript to read JS files, as
    // normally they are ignored as source files
    "allowJs": true,
    // Generate d.ts files
    "declaration": true,
    // This compiler run should
    // only output d.ts files
    "emitDeclarationOnly": true,
    // go to js file when using IDE functions like
    // "Go to Definition" in VSCode
    "declarationMap": true,
    "strict": true,
    "esModuleInterop": true,
    "types": ["node", "web", "serviceworker"]
  }
}