tsconfig.json

{
    "compilerOptions": {
        // Compilation options
        "sourceMap": true,
        "jsx": "react", // So we don't need babel after
        "lib": ["dom", "es5", "es2015.promise", "es6", "es2017"],
        "target": "es5", // Support older browser
        "module": "esnext",  // Let webpack do the job
        "moduleResolution": "node", // Auto get type from npm
        "importHelpers": true,
        // type checking option
        "noFallthroughCasesInSwitch": true,
        "noImplicitAny": true,
        "noImplicitReturns": true,
        "noUnusedLocals": true,
        "noImplicitThis": true,
        "allowSyntheticDefaultImports": true,
        "strictPropertyInitialization": true,
        "noUnusedParameters": true,
        "strictNullChecks": true,
        "strictFunctionTypes": true,
        "alwaysStrict": true,
        "esModuleInterop": true,
        "forceConsistentCasingInFileNames": true,
    },
    "exclude": [
        "node_modules"
    ]
}