tsconfig.json

{
  "compilerOptions": {
    "incremental": true,
    "outDir": "./build/",       // path to output directory
    "sourceMap": true,          // allow sourcemap support

    "alwaysStrict": true,
    // "noImplicitAny": true,
    "noImplicitThis": true,
    "strictBindCallApply": true,
    "strictFunctionTypes": true,
    "strictNullChecks": true,
    "strictPropertyInitialization": true,
    "noFallthroughCasesInSwitch": true,

    "module": "commonjs",
    "esModuleInterop": true,
    "jsx": "react",             // use typescript to transpile jsx to js
    "target": "es2019",
    "lib": [
      "DOM",
      "ES2019",
      "ScriptHost",
    ],

    // see https://github.com/DefinitelyTyped/DefinitelyTyped/issues/33015
    "types": ["node", "jest"],
  },
  "include": [
    "./src/"
  ]
}