tsconfig.json

{
  "compilerOptions": {
    /* Language and Environment */
    "target": "ES6",                                     /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
    
    /* Modules */
    "module": "commonjs",                                /* Specify what module code is generated. */
    "moduleResolution": "node",
    "rootDir": "./src",                                  /* Specify the root folder within your source files. */
    "outDir": "./lib",                                   /* Specify an output folder for all emitted files. */
    "declarationDir": "./lib",
    "declaration": true,
    "esModuleInterop": true,                             /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables 'allowSyntheticDefaultImports' for type compatibility. */
    "forceConsistentCasingInFileNames": true,            /* Ensure that casing is correct in imports. */

    /* Type Checking */
    "strict": true,                                      /* Enable all strict type-checking options. */
    "skipLibCheck": true                                 /* Skip type checking all .d.ts files. */
  },
  "exclude": ["./node_modules", "./lib"],
  "include": ["./src/**/*", "test/test.ts"]
}