tsconfig.json

{
  "compilerOptions": {
    "target": "es5",
    "outDir": "./build/",
    "rootDir": "./src",
    "module": "commonjs",
    "moduleResolution": "node",
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "strictFunctionTypes": true,
    "strictBindCallApply": true,
    "strictPropertyInitialization": false,
    "noImplicitThis": true,
    "alwaysStrict": true,
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "skipLibCheck": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "sourceMap": true,
    "typeRoots": ["./types", "./node_modules/@types"]
  }
}