go-test-coverage

Go Test Coverage

Test coverage gap analysis and recommendations for Go projects. Identifies missing or insufficient test coverage and generates actionable recommendations.

What It Does

1. Coverage Analysis — Runs go test -cover and parses results
2. Gap Identification — Finds untested exported functions, error paths, and edge cases
3. Recommendation Engine — Suggests specific test cases using table-driven patterns
4. Stub Generation — Creates ready-to-use test file stubs

Steps

API Integration (Optional)

If GOPHER_GUIDES_API_KEY is set, verify it:

curl -s -H "Authorization: Bearer $GOPHER_GUIDES_API_KEY" \
  https://gopherguides.com/api/gopher-ai/me

If not set, local analysis tools (go vet, staticcheck, golangci-lint) still provide comprehensive analysis. Set the key for enhanced API-powered insights. Get your key at gopherguides.com.

1. Measure Current Coverage

# Generate coverage profile
go test -coverprofile=coverage.out ./...

# View per-function coverage
go tool cover -func=coverage.out

# Generate HTML report (optional)
go tool cover -html=coverage.out -o coverage.html

2. Identify Gaps

Parse coverage output to find:

• Untested exported functions — Any func with 0% coverage
• Partially covered functions — Functions with branches not hit
• Untested error paths — if err != nil blocks never executed
• Missing edge cases — Boundary conditions not exercised

# Find functions with 0% coverage
go tool cover -func=coverage.out | grep "0.0%"

# Find exported functions without test files
for f in $(find . -name "*.go" ! -name "*_test.go" -path "*/pkg/*" -o -name "*.go" ! -name "*_test.go" -path "*/internal/*"); do
  dir=$(dirname "$f")
  base=$(basename "$f" .go)
  if [ ! -f "${dir}/${base}_test.go" ]; then
    echo "Missing test file: ${dir}/${base}_test.go"
  fi
done

3. Generate Recommendations

For each untested function, recommend: