tsconfig.json

{
  "compilerOptions": {
    "target": "es6" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */,
    "module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */,
    "outDir": "./lib" /* Redirect output structure to the directory. */,
    "rootDir": "./src" /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */,
    "strict": true /* Enable all strict type-checking options. */,
    "noImplicitAny": true /* Raise error on expressions and declarations with an implied 'any' type. */,
    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
    "baseUrl": "./",
    "resolveJsonModule": true
  },
  "exclude": ["node_modules", "**/*.test.ts"],
  "watchOptions": {
    // Use native file system events for files and directories
    "watchFile": "useFsEvents",
    "watchDirectory": "useFsEvents",
    // Poll files for updates more frequently
    // when they're updated a lot.
    "fallbackPolling": "dynamicPriority",
    // Don't coalesce watch notification
    "synchronousWatchDirectory": true,
    // Finally, two additional settings for reducing the amount of possible
    // files to track  work from these directories
    "excludeDirectories": ["**/node_modules", "dist"]
    // "excludeFiles": ["build/fileWhichChangesOften.ts"]
  }
}