Testing Strategy (Extracted)

Testing Strategy

Transform ad-hoc testing into systematic, coverage-driven strategy with 15x speedup.

Coverage is a means, quality is the goal. Systematic testing beats heroic testing.

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When to Use This Skill

Use this skill when:

• 🎯 Starting new project: Need systematic testing from day 1
• 📊 Coverage below 75%: Want to reach 80%+ systematically
• 🔧 Test infrastructure: Building fixtures, mocks, test helpers
• 🖥️ CLI applications: Need CLI-specific testing patterns
• 🔄 Refactoring legacy: Adding tests to existing code
• 📈 Quality gates: Implementing CI/CD coverage enforcement

Don't use when:

• ❌ Coverage already >90% with good quality
• ❌ Non-Go projects without adaptation (89% transferable, needs language-specific adjustments)
• ❌ No CI/CD infrastructure (automation tools require CI integration)
• ❌ Time budget <10 hours (methodology requires investment)

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Quick Start (30 minutes)

Step 1: Measure Baseline (10 min)

# Run tests with coverage
go test -coverprofile=coverage.out ./...
go tool cover -func=coverage.out

# Identify gaps
# - Total coverage %
# - Packages below 75%
# - Critical paths uncovered

Step 2: Apply Coverage-Driven Gap Closure (15 min)

Priority algorithm:

1. Critical paths first: Core business logic, error handling
2. Low-hanging fruit: Pure functions, simple validators
3. Complex integrations: File I/O, external APIs, CLI commands

Step 3: Use Test Pattern (5 min)

// Table-driven test pattern
func TestFunction(t *testing.T) {
    tests := []struct {
        name    string
        input   InputType
        want    OutputType
        wantErr bool
    }{
        {"happy path", validInput, expectedOutput, false},
        {"error case", invalidInput, zeroValue, true},
    }

    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            got, err := Function(tt.input)
            if (err != nil) != tt.wantErr {
                t.Errorf("error = %v, wantErr %v", err, tt.wantErr)
            }
            if !reflect.DeepEqual(got, tt.want) {
                t.Errorf("got %v, want %v", got, tt.want)
            }
        })
    }
}