tsconfig.json

{
  "compilerOptions": {
    "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */
    "module": "es6",                          /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
    "lib": ["es2015","dom"],                  /* Specify library files to be included in the compilation. */
    "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. */
    "strictNullChecks": false,
    "resolveJsonModule": true,
    "moduleResolution": "node",               /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
    "esModuleInterop": true,                  /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
    "skipLibCheck": true,                     /* Skip type checking of declaration files. */
    "allowJs": true,
    "forceConsistentCasingInFileNames": true  /* Disallow inconsistently-cased references to the same file. */
  },
  "include": [
    "src/*.ts",
    "src/*.js",
    "src/**/*.ts",
    "src/**/*.js"
  ]
}