tsconfig.json

{
    "compilerOptions": {
      "outDir": "build",
      "module": "esnext",
      "target": "es5",
      "lib": ["es6", "dom", "es2016", "es2017"],
      "sourceMap": true,
      "allowJs": false,
      "jsx": "preserve",
      "declaration": true,
      "moduleResolution": "node",
      "forceConsistentCasingInFileNames": true,
      "noImplicitReturns": true,
      "noImplicitThis": true,
      "noImplicitAny": true,
      "strictNullChecks": true,
      "suppressImplicitAnyIndexErrors": true,
      "noUnusedLocals": true,
      "noUnusedParameters": true,
      "skipLibCheck": false,
      "esModuleInterop": true,
      "allowSyntheticDefaultImports": true,
      "strict": true,
      "resolveJsonModule": true,
      "isolatedModules": true,
      "noEmit": true
    },
    "include": ["./src"]
  }