tsconfig.json

{
  "compilerOptions": {
    "target": "es2015",
    "module": "es6",
    "noImplicitAny": true,
    "strictNullChecks": true,
    "strictFunctionTypes": true,
    "strictBindCallApply": true,
    "strictPropertyInitialization": true,
    "noImplicitThis": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    "skipLibCheck": true,
    "resolveJsonModule": true,
    "moduleResolution": "node",
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "outDir": "dist/esm",
    "declaration": true,
    "declarationDir": "dist/types",
    "importHelpers": true,
    "allowJs": true,
    "allowSyntheticDefaultImports": true,
    "sourceMap": true,
    "typeRoots": [
      "./node_modules/@types",
      "./typings"
    ]
  },
  "include": [
    "./src/**/*", "./typings"
  ],
  "exclude": [
    "./src/**/__tests__/*"
  ]
}