tsconfig.json

{
  "compilerOptions": {
    "target": "ES6",
    "esModuleInterop": true,
    "module": "commonjs",
    "moduleResolution": "node",
    "allowSyntheticDefaultImports": true,
    "allowJs": false,
    "skipLibCheck": true,
    "importHelpers": true,
    "alwaysStrict": true,
    "sourceMap": true,
    "forceConsistentCasingInFileNames": true,
    "noFallthroughCasesInSwitch": true,
    "noImplicitReturns": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noImplicitAny": false,
    "noImplicitThis": false,
    "strictNullChecks": false,
    "lib": ["ES6", "ES2019", "DOM"],
    "declaration": true,
    "declarationMap": true
  },
  "include": ["src/**/*", "__tests__/**/*"],
  "exclude": ["build/*"]
}