tsconfig.json

{
  "compilerOptions": {
    "allowSyntheticDefaultImports": true,
    "declaration": true,
    "esModuleInterop": true,
    "inlineSourceMap": true,
    "module": "es2015",
    "moduleResolution": "node",
    "noFallthroughCasesInSwitch": true,
    "noImplicitAny": true,
    "noImplicitReturns": true,
    "noImplicitThis": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "outDir": "./.tmp/es2015/",
    "removeComments": true,
    "rootDir": "./",
    "sourceMap": false,
    "strict": true,
    "target": "es2015"
  },
  "files": [
    "./src/index.ts",
    "./test/index.ts"
  ]
}