Charon/docs/implementation/FRONTEND_TEST_HANG_FIX.md

Frontend Test Hang Fix

Problem

Frontend tests took 1972 seconds (33 minutes) instead of the expected 2-3 minutes.

Root Cause

1. Missing frontend/src/setupTests.ts file that was referenced in vite.config.ts
2. No test timeout configuration in Vitest
3. Outdated backend tests referencing non-existent functions

Solutions Applied

1. Created Missing Setup File

File: frontend/src/setupTests.ts

import '@testing-library/jest-dom'

// Setup for vitest testing environment

2. Added Test Timeouts

File: frontend/vite.config.ts

test: {
  globals: true,
  environment: 'jsdom',
  setupFiles: './src/setupTests.ts',
  testTimeout: 10000, // 10 seconds max per test
  hookTimeout: 10000, // 10 seconds for beforeEach/afterEach
  coverage: { /* ... */ }
}

3. Fixed Backend Test Issues

• Fixed: backend/internal/api/handlers/dns_provider_handler_test.go

  • Updated MockDNSProviderService.GetProviderCredentialFields signature to match interface
  • Changed from (required, optional []dnsprovider.CredentialFieldSpec, err error) to ([]dnsprovider.CredentialFieldSpec, error)

• Removed: Outdated test files and functions:

  • backend/internal/services/plugin_loader_test.go (referenced non-existent NewPluginLoader)
  • TestValidateCredentials_AllRequiredFields (referenced non-existent ProviderCredentialFields)
  • TestValidateCredentials_MissingEachField (referenced non-existent constants)
  • TestSupportedProviderTypes (referenced non-existent SupportedProviderTypes)

Results

Before Fix

• Frontend tests: 1972 seconds (33 minutes)
• Status: Hanging, eventually passing

After Fix

• Frontend tests: 88 seconds (1.5 minutes) ✅
• Speed improvement: 22x faster
• Status: Passing reliably

QA Suite Status

All QA checks now passing:

• ✅ Backend coverage: 85.1% (threshold: 85%)
• ✅ Frontend coverage: 85.31% (threshold: 85%)
• ✅ TypeScript check: Passed
• ✅ Pre-commit hooks: Passed
• ✅ Go vet: Passed
• ✅ CodeQL scans (Go + JS): Completed

Prevention

To prevent similar issues in the future:

1. Always create setup files referenced in config before running tests
2. Set reasonable test timeouts to catch hanging tests early
3. Keep tests in sync with code - remove/update tests when refactoring
4. Run go vet locally before committing to catch type mismatches

Files Modified

1. /frontend/src/setupTests.ts (created)
2. /frontend/vite.config.ts (added timeouts)
3. /backend/internal/api/handlers/dns_provider_handler_test.go (fixed mock signature)
4. /backend/internal/services/plugin_loader_test.go (deleted)
5. /backend/internal/services/dns_provider_service_test.go (removed outdated tests)