feat: Implement comprehensive test suite for Activity API (004-activity-api-tests)

[willvelida]

Overview

Implements comprehensive test coverage for Activity API achieving 79.3% code coverage with 104 passing tests.

Resolves #4-activity-api-tests

Test Coverage Summary

Test Type	Count	Status
Unit Tests	74	✅ All Passing
Contract Tests	18	✅ All Passing
E2E Tests	12	✅ All Passing
Total	104	100% Success

Code Coverage: 79.3% (excludes Program.cs entry point per decision record)

Changes

Test Infrastructure

Unit Tests (74 tests):

• ActivityHandlersShould.cs - 16 tests for endpoint handler logic including date validation
• CosmosRepositoryShould.cs - 17 tests for database operations and error handling
• ActivityShould.cs - 15 tests for Fitbit entity mappings
• EndpointRouteBuilderExtensionsShould.cs - 16 tests for endpoint registration
• SettingsShould.cs - 10 tests for configuration validation

Integration Tests (30 tests):

• Contract Tests (18 tests):
  • ProgramStartupTests.cs - Verify application startup and DI container
  • ApiSmokeTests.cs - Validate HTTP pipeline and health checks
• E2E Tests (12 tests):
  • ActivityEndpointsTests.cs - Full integration with Cosmos DB Emulator
  • Tests GET /activities, GET /activities/{date}, GET /activities/range endpoints
  • Includes performance and data persistence validation

Test Fixtures:

• IntegrationTestFixture - Cosmos DB Emulator connection management
• ActivityApiWebApplicationFactory - WebApplicationFactory with Gateway mode for E2E tests
• ContractTestFixture - Fast contract test fixture for DI validation
• TestDataHelper - Generate consistent test data

API Enhancements

• ✅ Add date format validation in GetActivityByDate handler (returns 400 Bad Request for invalid dates)
• ✅ Fix GetAllActivities to return 200 OK with empty array when no data exists (was incorrectly returning 404)

Cosmos DB Emulator Infrastructure

Local Development:

• docker-compose.cosmos.yml - Container configuration for local emulator
• cosmos-emulator.ps1 - PowerShell helper script with start/stop/status/cert commands
• docs/cosmos-emulator-setup.md - Comprehensive setup guide with troubleshooting

Key Configuration:

• Uses Gateway mode (HTTPS port 8081) instead of Direct mode to avoid SSL negotiation issues
• Configured with 10 partitions, no data persistence for fast test execution
• Certificate validation bypass for local development

CI/CD Integration

GitHub Actions Workflow Updates (deploy-activity-api.yml):

• ✅ Added run-e2e-tests job using template-dotnet-run-e2e-tests.yml
• ✅ E2E tests run in parallel with deployment using Cosmos DB Emulator service container
• ✅ Test filter: FullyQualifiedName~E2E to match E2E namespace pattern
• ✅ All 104 tests will now execute in CI/CD pipeline

Workflow Execution:

1. Unit tests (70% coverage threshold)
2. Contract tests (parallel with unit tests)
3. E2E tests (parallel with deployment, uses Cosmos DB Emulator)
4. Build container image
5. Deploy to dev environment

Documentation

• ✅ README files for test projects with setup and execution instructions
• ✅ Updated common-resolutions.md with Gateway mode fix for SSL negotiation issues
• ✅ Added decision record for coverlet extension method coverage anomaly
• ✅ Updated copilot-instructions.md with test patterns and technologies
• ✅ Complete spec documentation in specs/004-activity-api-tests/

Testing Instructions

Run All Tests Locally

# Start Cosmos DB Emulator
.\cosmos-emulator.ps1 start

# Wait for emulator to be healthy (takes ~2 minutes)
.\cosmos-emulator.ps1 status

# Run all tests
cd src/Biotrackr.Activity.Api
dotnet test --verbosity minimal

# Stop emulator when done
.\cosmos-emulator.ps1 stop

Run Specific Test Types

# Unit tests only
dotnet test --filter "FullyQualifiedName!~IntegrationTests"

# Contract tests only
dotnet test --filter "FullyQualifiedName~Contract"

# E2E tests only (requires Cosmos DB Emulator)
dotnet test --filter "FullyQualifiedName~E2E"

Key Technical Decisions

1. Gateway Mode for Cosmos DB: Uses Gateway mode (HTTPS) instead of Direct mode (TCP+SSL) to avoid SSL certificate negotiation issues with the emulator's self-signed certificate (documented in common-resolutions.md)

2. Test Organization: Separated contract tests (fast, no dependencies) from E2E tests (requires Cosmos DB) using namespace-based organization (decision record)

3. Parallel CI/CD Execution: E2E tests run in parallel with deployment since they use the emulator, not the deployed environment, reducing pipeline duration

4. Date Validation: Added input validation at the handler level to return 400 Bad Request before making repository calls, improving API correctness

Checklist

• All tests passing locally (104/104)
• Code coverage meets threshold (79.3% > 70%)
• Unit tests implemented for all handlers, repository, models, extensions, configuration
• Contract tests validate DI and startup behavior
• E2E tests validate endpoints with Cosmos DB integration
• GitHub Actions workflow updated with E2E test job
• Cosmos DB Emulator setup documented and automated
• README files added for test projects
• Decision records created for key technical choices
• Common resolutions documented for troubleshooting

Screenshots

Local Test Execution:

Test summary: total: 104, failed: 0, succeeded: 104, skipped: 0, duration: 8.9s
Build succeeded

Coverage Report:

| Module                 | Line   | Branch | Method |
|------------------------|--------|--------|--------|
| Biotrackr.Activity.Api | 79.3%  | 76.3%  | 79.6%  |

Related Issues

• Implements feature Adding Budgets to core infra. Adding Bicep Modules Structure doc. Upd… #4-activity-api-tests
• Follows patterns established in Adding inital infra cut #1-weight-api-tests
• Uses infrastructure from Updating core infra workflow to target templates on main. Updating RE… #3-weight-svc-integration-tests

[github-actions]

Package	Line Rate	Branch Rate	Health
Biotrackr.Activity.Api	80%	86%	➖
Summary	80% (214 / 269)	86% (24 / 28)	➖

Minimum allowed line rate is 70%