React Native Research & Evidence-Based Practice 4 — Questions and Answers
Question 1: Evidence-based analysis of React Native CI/CD pipelines shows which service is most widely adopted for automating iOS and Android builds?
- Jenkins
- Fastlane (Correct answer)
- CircleCI
- Bitrise
Correct answer: Fastlane
Fastlane automates codesigning, building, testing, and deployment for both iOS and Android and is the most widely adopted automation tool in the React Native community.
Question 2: Research on over-the-air (OTA) updates in React Native shows which service enables pushing JavaScript bundle updates without going through the App Store review process?
- Expo EAS Build
- CodePush (App Center) (Correct answer)
- Firebase App Distribution
- TestFlight
Correct answer: CodePush (App Center)
CodePush by Microsoft App Center allows teams to push JS bundle and asset updates directly to users' devices, bypassing full App Store / Play Store review cycles.
Question 3: A researcher benchmarks animation approaches in React Native. Which API is evidence-based best practice for smooth 60fps animations that run on the UI thread?
- Animated API with useNativeDriver: true (Correct answer)
- setInterval-based state updates
- Animated API without useNativeDriver
- CSS transitions via StyleSheet
Correct answer: Animated API with useNativeDriver: true
Setting useNativeDriver: true offloads animation calculations to the native UI thread, bypassing the JS bridge and enabling smooth 60fps animations even when the JS thread is busy.
Question 4: Evidence from React Native community surveys consistently shows that which approach to TypeScript adoption leads to the fewest runtime type errors in large codebases?
- Using 'any' type liberally to speed up development
- Enabling strict mode in tsconfig.json from project start (Correct answer)
- Adding TypeScript to an existing JavaScript project gradually
- Using PropTypes alongside TypeScript for redundancy
Correct answer: Enabling strict mode in tsconfig.json from project start
Enabling strict mode (which activates strictNullChecks, noImplicitAny, and related flags) from project inception prevents entire classes of null/undefined runtime errors.
Question 5: Research on React Native bundle size optimization identifies which technique as most impactful for reducing the initial JavaScript bundle delivered to users?
- Removing all comments from source files
- Using inline requires (lazy loading) for non-critical modules (Correct answer)
- Switching from npm to yarn for package management
- Disabling source maps in production
Correct answer: Using inline requires (lazy loading) for non-critical modules
Inline requires defer the loading of modules until they are first used, reducing the amount of JavaScript parsed and executed at startup, which is the primary evidence-based bundle size technique.
Question 6: Based on empirical reports from React Native teams, what is the most common root cause of the 'white screen of death' (blank screen on launch)?
- Missing splash screen configuration
- A JavaScript error thrown synchronously during app initialization before the error boundary renders (Correct answer)
- Incorrect entry point in package.json
- Missing fonts causing render failure
Correct answer: A JavaScript error thrown synchronously during app initialization before the error boundary renders
Synchronous JS errors during initialization crash the JS runtime before any UI renders, resulting in a blank white screen; adding a global error boundary and logging catches these.
Question 7: Research into React Native monorepo setups recommends which tool as the evidence-based standard for managing shared packages across React Native and web projects?
- Lerna with npm workspaces
- Nx
- Turborepo (Correct answer)
- Yarn workspaces with Expo's monorepo template
Correct answer: Turborepo
Turborepo is widely validated in community research for its incremental build caching and task pipeline capabilities, making it the most adopted monorepo build tool for React Native + web projects.
React Native Research & Evidence-Based Practice 4
Evidence-based analysis of React Native CI/CD pipelines shows which service is most widely adopted for automating iOS and Android builds?