tsconfig.json

{
  "compilerOptions": {
    /* Basic Options */
    "target":
      "ES2017" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */,
    "module":
      "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */,
    // "lib": [],                             /* Specify library files to be included in the compilation. */
    "declaration": true /* Generates corresponding '.d.ts' file. */,
    "sourceMap": true,
    // "outFile": "./",                       /* Concatenate and emit output to single file. */
    "outDir": "./lib" /* Redirect output structure to the directory. */,
    "rootDir": "./src" /* Specify the root directory of input files. */,

    "strict": true /* Enable all strict type-checking options. */,
    // "noUnusedLocals": true /* Report errors on unused locals. */,
    "noImplicitReturns": true /* Report error when not all code paths in function return a value. */,
    // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
    // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
    // "typeRoots": [],                       /* List of folders to include type definitions from. */
    // "types": [],                           /* Type declaration files to be included in compilation. */
    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
    "sourceRoot": "src",
    "mapRoot": "lib"
    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
  },
  "include": ["./src/**/*"],
  "exclude": ["node_modules"]
}