tsconfig.json

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "es6",
    "declaration": true,
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "removeComments": true,
    "allowSyntheticDefaultImports": true,
    "preserveConstEnums": true,
    "sourceMap": true,
    "strictNullChecks": false,
    "forceConsistentCasingInFileNames": true,
    "noFallthroughCasesInSwitch": true,
    "noImplicitAny": false,
    "noImplicitReturns": true,
    "noImplicitThis": false,
    "noUnusedLocals": true,
    "noUnusedParameters": false,
    "outDir": "./node_modules",
    "lib": ["es2017", "es2016", "es2015", "es6", "dom", "esnext.asynciterable"],
    "typeRoots": ["node_modules/@types"]
  },
  "include": ["./src/**/*"],
  "exclude": ["node_modules/**/*", "./src/**/*.spec.ts"]
}