tsconfig.json

{
  "compilerOptions": {
    /* Basic Options */
    "target": "es5" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' 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. */,
    "declarationMap": true /* Generates a sourcemap for each corresponding '.d.ts' file. */,
    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
    "outDir": "lib" /* Redirect output structure to the directory. */,
    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */

    /* Strict Type-Checking Options */
    "strict": true /* Enable all strict type-checking options. */,

    /* Additional Checks */
    "noUnusedLocals": true /* Report errors on unused locals. */,
    "noUnusedParameters": true /* Report errors on unused parameters. */,
    "noImplicitReturns": true /* Report error when not all code paths in function return a value. */,
    "noFallthroughCasesInSwitch": true /* Report errors for fallthrough cases in switch statement. */,

    /* Module Resolution Options */
    // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
    "moduleResolution": "node",
    "resolveJsonModule": true
  },
  "include": ["src"],
  "exclude": [
    "**/*.spec.ts",
    "**/__fixtures__/*",
    "**/__tests__/*",
    "**/__snapshots__/*"
  ]
}