tsconfig.json

{
    "compilerOptions": {
      /* Visit https://aka.ms/tsconfig to read more about this file */

      /* Language and Environment */
      "target": "es2016", /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
      "experimentalDecorators": true, /* Enable experimental support for legacy experimental decorators. */
      "emitDecoratorMetadata": true, /* Emit design-type metadata for decorated declarations in source files. */

      /* Modules */
      "module": "CommonJS", /* Specify what module code is generated. */
      "moduleResolution": "node", /* Specify how TypeScript looks up a file from a given module specifier. */
      "baseUrl": "./src", /* Specify the base directory to resolve non-relative module names. */
      "resolveJsonModule": true, /* Enable importing .json files. */

      /* Emit */
      "sourceMap": true, /* Create source map files for emitted JavaScript files. */
      "outDir": "./lib", /* Specify an output folder for all emitted files. */

      /* Interop Constraints */
      "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. */
      "declaration": true,
      
      /* Type Checking */
      "strict": true, /* Enable all strict type-checking options. */
      "strictNullChecks": true, /* When type checking, take into account 'null' and 'undefined'. */

      /* Completeness */
      "skipLibCheck": true, /* Skip type checking all .d.ts files. */

      /* Output Formatting */
      "pretty": true /* Stylize errors and messages using color and context, this is on by default */
    },
    "include": [
      "src/**/*"
    ],
    "exclude": [
      "node_modules"
    ]
  }