tsconfig.json

{
    "compilerOptions": {
        /* core */
        "target": "ES2017",
        "module": "ESNext",
        "moduleResolution": "node",
        "outDir": "./dist/lib",

        /* strictness */
        "strict": true,
        "noImplicitAny": true,
        "strictNullChecks": true,
        "strictFunctionTypes": true,
        "strictBindCallApply": true,
        "strictPropertyInitialization": true,
        "noImplicitThis": true,
        "alwaysStrict": true,
        "noImplicitReturns": true,

        /* misc */
        "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
        "experimentalDecorators": true,
        "emitDecoratorMetadata": true,
        "removeComments": true,
        "sourceMap": true,

        /* typings */
        "typeRoots": ["node_modules/@jest", "node_modules/@types", "src/typings"]
    },
    "exclude": ["node_modules"]
}