add_test_implementation_1766933675

Author: Dagger

TESTING.md

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+# Test Documentation
+
+This document describes the comprehensive testing approach for the Greetings API project.
+
+## Overview
+
+The Greetings API project includes multiple layers of testing to ensure reliability and correctness:
+- Unit tests for backend logic
+- End-to-end tests for the frontend
+- Linting for code quality
+
+## Backend Tests
+
+The backend tests are located in `main_test.go` and use the `gotest.tools/v3` testing framework.
+
+### Test Functions
+
+#### TestSelectGreeting
+Tests the core greeting selection logic with multiple scenarios:
+- **Valid language selection**: Tests retrieval of greetings by specific language (e.g., "english")
+- **Random selection**: Tests the random greeting functionality
+- **Invalid language handling**: Verifies proper error handling for non-existent languages
+- **Empty language handling**: Ensures errors are returned for empty language strings
+
+#### TestFormatResponse
+Tests the JSON response formatting:
+- Verifies the greeting is properly formatted as JSON
+- Ensures the structure matches the expected API response format: `{"greeting":"<message>"}`
+
+### Test Coverage
+
+Current test coverage includes:
+- ✅ Greeting selection by language
+- ✅ Random greeting selection  
+- ✅ Error handling for invalid languages
+- ✅ Error handling for empty language strings
+- ✅ Response formatting
+- ✅ Empty greetings slice handling
+
+## Frontend Tests
+
+End-to-end tests for the frontend are located in `website/cypress/e2e/greeting_test.cy.ts` using Cypress.
+
+### Test Scenarios
+
+1. **Page Load Test**: Verifies the page loads correctly with the expected header
+2. **Greeting Button Test**: Verifies clicking the greeting button changes the displayed message
+
+## Running Tests
+
+### All Tests (Recommended)
+```bash
+dagger call check
+```
+
+This runs:
+- Backend linting (golangci-lint)
+- Backend unit tests
+- Frontend E2E tests
+- Frontend linting
+
+### Backend Tests Only
+```bash
+# Using Dagger
+dagger call test
+
+# Or directly with Go
+go test ./...
+```
+
+### Frontend Tests Only
+```bash
+cd website
+npm run test:e2e
+```
+
+### Linting Only
+```bash
+# Backend
+dagger call lint
+
+# Frontend (part of check command)
+dagger call check
+```
+
+## Test Data
+
+Greetings test data is embedded from `greetings.json` which includes:
+- 17 different language greetings
+- Languages: English, British, French, Italian, Spanish, German, Mandarin, Hindi, Arabic, Bengali, Russian, Portuguese, Urdu, Indonesian, Japanese, Marathi, Telugu
+
+## Continuous Integration
+
+Tests are automatically run in CI through Dagger modules. The CI ensures:
+- All tests pass before merging
+- Code meets linting standards
+- No regressions are introduced
+
+## Future Test Improvements
+
+Potential areas for additional testing coverage:
+- HTTP handler integration tests (testing the actual HTTP endpoints with httptest)
+- Additional edge cases for error handling
+- Performance/load testing for the API
+- Testing CORS functionality
+- Testing with empty greetings.json
+- Concurrency testing for random selection
+
+## Test Best Practices
+
+When adding new tests:
+1. Follow Go testing conventions
+2. Use descriptive test function names
+3. Test both happy paths and error cases
+4. Keep tests isolated and independent
+5. Run `dagger call check` before committing
+6. Update this documentation when adding new test scenarios