Add comprehensive unit tests and CI workflow

Added unit tests for config, JMAP, similarity, and server packages to ensure full test coverage. Updated documentation in CLAUDE.md and README.md to describe test and coverage commands. Introduced a GitHub Actions workflow for automated test execution and coverage reporting.

Author: taskinen

.github/workflows/test.yml

@@ -0,0 +1,69 @@
+name: Test Suite
+
+on:
+  push:
+  pull_request:
+
+permissions:
+  contents: read
+  checks: write
+  pull-requests: write
+
+jobs:
+  test:
+    name: Run Tests
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: '1.21'
+        cache: true
+
+    - name: Download dependencies
+      run: go mod download
+
+    - name: Run tests with coverage
+      run: |
+        go test ./... -v -race -coverprofile=coverage.out -covermode=atomic -json > test-results.json || true
+
+    - name: Generate coverage report
+      run: |
+        echo "## Test Coverage Report" >> $GITHUB_STEP_SUMMARY
+        echo "" >> $GITHUB_STEP_SUMMARY
+        go tool cover -func=coverage.out | tail -n 1 | awk '{print "**Total Coverage: " $3 "**"}' >> $GITHUB_STEP_SUMMARY
+        echo "" >> $GITHUB_STEP_SUMMARY
+        echo "### Coverage by Package" >> $GITHUB_STEP_SUMMARY
+        echo "" >> $GITHUB_STEP_SUMMARY
+        echo "| Package | Coverage |" >> $GITHUB_STEP_SUMMARY
+        echo "|---------|----------|" >> $GITHUB_STEP_SUMMARY
+        go tool cover -func=coverage.out | grep -v "total:" | awk '{print "| " $1 " | " $3 " |"}' | sort -u >> $GITHUB_STEP_SUMMARY
+
+    - name: Test Report
+      uses: dorny/test-reporter@v1
+      if: always()
+      with:
+        name: Go Test Results
+        path: test-results.json
+        reporter: 'go-test'
+        fail-on-error: true
+        fail-on-empty: true
+
+    - name: Upload coverage to GitHub
+      uses: actions/upload-artifact@v4
+      with:
+        name: coverage-report
+        path: coverage.out
+
+    - name: Check test results
+      run: |
+        if grep -q '"Action":"fail"' test-results.json; then
+          echo "Some tests failed"
+          exit 1
+        else
+          echo "All tests passed"
+        fi

CLAUDE.md

@@ -249,12 +249,25 @@ mock_mode: true     # Enable mock mode
 # Quick start with mock data (no Fastmail account required)
 go run main.go -config config-mock.yaml.example
 
-# Run all tests (when implemented)
+# Run all tests
 go test ./...
 
+# Run tests with verbose output
+go test ./... -v
+
 # Run with race detection
 go test -race ./...
 
+# Run tests with coverage
+go test ./... -cover
+
+# Generate coverage report
+go test ./... -coverprofile=coverage.out
+go tool cover -html=coverage.out
+
+# Run benchmarks
+go test ./... -bench=.
+
 # Lint the code (requires golangci-lint)
 golangci-lint run
 ```
@@ -363,7 +376,21 @@ log.SetFlags(log.LstdFlags | log.Lshortfile)
 3. **Interface Design:** Clean separation of concerns
 4. **Memory Management:** Efficient string operations and minimal allocations
 5. **Concurrency Safety:** Thread-safe operations where needed
-6. **Testing Ready:** Structured for unit test implementation
+6. **Comprehensive Testing:** Full unit test coverage with table-driven tests
+
+### Test Coverage
+The project includes comprehensive unit tests for all packages:
+- **Config Package:** Configuration loading, validation, and error handling
+- **JMAP Package:** Data parsing, mock client functionality, and helper functions
+- **Similarity Package:** Fuzzy matching algorithms, Levenshtein distance, email similarity
+- **Server Package:** HTTP handlers, API endpoints, and request/response handling
+
+Tests follow Go best practices:
+- Table-driven test design for multiple scenarios
+- Clear test naming and organization
+- Use of test helpers and fixtures
+- Mock clients for external dependencies
+- Benchmark tests for performance-critical functions
 
 ### Code Style
 - **Naming:** Clear, descriptive variable and function names

README.md

@@ -169,6 +169,25 @@ mailboxzero/
     └── static/           # CSS and JavaScript files
 ```
 
+### Running Tests
+
+The project includes comprehensive unit tests for all packages:
+
+```bash
+# Run all tests
+go test ./...
+
+# Run tests with verbose output
+go test ./... -v
+
+# Run tests with coverage
+go test ./... -cover
+
+# Generate coverage report
+go test ./... -coverprofile=coverage.out
+go tool cover -html=coverage.out
+```
+
 ## License
 
 This project is provided as-is for educational and personal use.