tsconfig.json

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs",
    "rootDir": "src",
    "baseUrl": "src",
    "sourceMap": true,
    "lib": ["es2017", "dom", "DOM.Iterable"],
    "forceConsistentCasingInFileNames": true,
    "declaration": true,
    "declarationMap": true,
    "outDir": "dist/esm5",
    "removeComments": true,
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "strictFunctionTypes": true,
    "strictPropertyInitialization": true,
    "noImplicitThis": true,
    "alwaysStrict": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    "moduleResolution": "node",
    "allowSyntheticDefaultImports": true,
    "esModuleInterop": true,
    "resolveJsonModule": true
  },
  "exclude": ["node_modules", "dist", "tests", "**/tests/*.test.ts"]
}