[IMPROVEMENT] Test coverage increase and flaky test resolution [Size: M, P...

[devwif]

[IMPROVEMENT] Increase Test Coverage & Resolve Flaky Tests to Boost Stability and Confidence [Size: M, Priority: Normal]

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📢 Problem Statement

The current test suite for the larp0/wallet-adapter repo exhibits gaps in coverage and contains flaky tests that intermittently fail without code changes. This undermines our ability to confidently ship new features and refactor existing code without risking regressions or broken wallet integrations in production.

We need to systematically increase test coverage across critical modules and eliminate flaky tests to reduce release risk, improve developer experience, and raise overall code quality.

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🔍 Technical Context

• The wallet-adapter repo is a modular monorepo written primarily in TypeScript, focusing on wallet adapters and React components for Solana-based apps.
• Current tests include unit tests but lack comprehensive coverage and have flaky tests causing unstable CI results.
• Flaky tests might stem from asynchronous timing issues, external API dependencies, or insufficient mocks.
• Robust testing is crucial to secure wallet integrations, as bugs or regressions could lead to severe financial or security implications.
• The repo uses testing scripts triggered via the test npm script; the testing framework and coverage tooling should be identified and leveraged for enhancements.

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🛠️ Detailed Implementation Steps

1. Analyze Current Test Suite

   • Extract current coverage reports (e.g., using nyc, jest --coverage) and identify files or modules with <70% coverage.
   • Identify flaky tests via:
     • Reviewing recent CI failures.
     • Running tests repeatedly locally (jest --runInBand --repeat) to detect non-deterministic failures.
   • Document flaky test cases, root causes (timeouts, race conditions, external dependencies), and affected modules.

2. Define Test Coverage Goals

   • Target at least 85% coverage on all critical modules related to wallet connection, transaction signing, and adapter lifecycle.
   • Ensure all public APIs have corresponding positive and negative test cases.
   • Include edge cases and error handling paths.

3. Fix Flaky Tests

   • Refactor flaky tests by:
     • Adding appropriate mocks/stubs for external calls (RPC, network).
     • Using controlled timers or async utilities (e.g., jest.useFakeTimers()).
     • Increasing timeouts or restructuring tests to avoid race conditions.
   • If a test remains flaky and non-critical, consider temporarily quarantining with clear TODOs.

4. Add Missing Tests

   • Write new unit tests for uncovered functions, especially:
     • State management logic of wallet adapters.
     • Event emission and listener behavior.
     • React component lifecycle and props handling.
   • Add integration tests simulating real wallet connection workflows.

5. Ensure Backward Compatibility

   • Verify that new tests and fixes do not break existing APIs or expected behavior.
   • Run tests on multiple Node versions if supported, currently Node 20+ recommended.

6. Update CI Pipeline

   • Integrate coverage thresholds to fail builds if coverage drops below targets.
   • Add retry logic or quarantine for flaky tests if needed.
   • Run tests in parallel and serial modes to catch concurrency issues.

7. Document Findings and Improvements

   • Update the repo README or CONTRIBUTING.md with testing guidelines.
   • Create a wiki page summarizing flaky tests and resolutions.
   • Document new coverage targets and how to run tests locally.

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📐 Technical Specifications

• Testing Framework: Jest (assuming from typical TypeScript React projects; confirm and align)
• Coverage Tool: jest --coverage or nyc
• Mocking: Use jest.mock() or similar for external dependencies
• Test Types to Add:
  • Unit Tests with full assertion coverage for logic-heavy modules
  • Integration Tests for wallet adapter workflows
  • Flaky Test Fixes with async utilities or mocks
• Performance Impact: Tests should run efficiently; avoid excessive timeouts

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✅ Acceptance Criteria

• Comprehensive coverage report generated and reviewed
• Coverage improved to ≥ 85% on all critical wallet adapter modules
• All known flaky tests identified and either fixed or quarantined with documentation
• New and existing tests pass consistently on CI without intermittent failures
• CI pipeline enforces coverage thresholds and stable test runs
• Documentation updated with testing guidelines and flaky test resolutions
• No regressions or backward compatibility breaks introduced

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🧪 Testing Requirements

• Run full test suite with coverage enabled locally and on CI
• Perform repeated test runs to verify flaky test fixes
• Validate coverage threshold enforcement in CI
• Test on Node 20+ environment as required by recent commits
• Manual exploratory testing of wallet adapters after fixes to verify runtime stability

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📚 Documentation Needs

• Update README.md or CONTRIBUTING.md with:
  • How to run tests and generate coverage reports
  • Testing best practices for wallet adapters
• Add a new Wiki/Docs page on flaky tests analysis and resolution strategies
• Document coverage goals and how to interpret coverage reports
• Document any new test utilities or mocks introduced

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⚠️ Potential Challenges

• Flaky tests may be caused by complex async flows or external RPC dependencies; require careful mocking
• Balancing coverage improvement with not over-testing trivial code paths
• Ensuring tests remain maintainable and do not increase CI time excessively
• Coordinating with ongoing feature development to avoid merge conflicts in test files
• Possible gaps in understanding specific wallet adapter internal state flows requiring domain knowledge

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🔗 Resources & References

• Jest Docs: https://jestjs.io/docs/getting-started
• Jest Async Testing: https://jestjs.io/docs/asynchronous
• Code Coverage with Jest: https://jestjs.io/docs/code-coverage
• Mocking External Modules: https://jestjs.io/docs/mock-functions
• Solana Wallet Adapter Repo: https://github.com/larp0/wallet-adapter
• Example of flaky test handling: https://kentcdodds.com/blog/common-mistakes-with-react-testing-library
• Testing React Components: https://testing-library.com/docs/react-testing-library/intro/

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Let’s embark on this noble quest to vanquish flaky tests and illuminate the dark corners of our test coverage!

Your efforts will safeguard millions of Solana transactions and empower devs worldwide to innovate with confidence. 🚀✨

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Checklist

• Analyze current coverage and flaky tests
• Document flaky tests and root causes
• Fix flaky tests with mocks/timeouts/retries
• Add new unit and integration tests to close coverage gaps
• Update CI to enforce coverage and stable runs
• Update documentation with testing guidelines and findings
• Verify no regressions on Node 20+ environments
• Final review and merge

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Feel free to reach out if you need any help or brainstorming on tricky flaky test fixes — together we’ll make this repo rock-solid!