tsconfig.json

{
  "compilerOptions": {
    "target": "es5" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', or 'ESNEXT'. */,
    "outDir": "./dist" /* 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. */,
    "strictNullChecks": true,
    "module": "commonjs",
    "sourceMap": true,
    "noImplicitAny": true,
    "noImplicitThis": true,
    "lib": ["es5", "es2017", "dom"],
    "declaration": true,
    "resolveJsonModule": true,
    "esModuleInterop": true,
  },
  "include": ["src/**/*"],
  "exclude": ["test/**/*", "preview/**/*"],
}