tsconfig.json

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs",
    "allowJs": true,
    "declaration": true,
    "declarationMap": true,
    "rootDir": "./src",
    "outDir": "./dist",
    "resolveJsonModule": true,
    "sourceMap": true,

    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "strictFunctionTypes": true,
    "strictBindCallApply": true,
    "strictPropertyInitialization": true,
    "noImplicitThis": true,
    "alwaysStrict": true,

    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,

    "esModuleInterop": true,

    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,

    "lib": ["es2017"]
  },

  "include": [
    "./src/**/*.ts"
  ]
}