gen-test

name	gen-test
description	Generate table-driven Go tests matching gh-history project conventions
disable-model-invocation	true

Generate Go Tests

Generate table-driven Go tests for the specified Go source file, following this project's conventions.

Conventions

• Tests live in colocated *_test.go files (same package, same directory)
• Use standard testing package — no external test frameworks
• Prefer table-driven tests with t.Run subtests for multiple cases
• Use t.Fatal/t.Fatalf for setup failures, t.Error/t.Errorf for assertion failures
• Helper functions are defined at the top of test files (e.g., d(year, month, day) for date construction in daterange tests)
• Test function names: Test<FunctionName>_<Scenario> (e.g., TestBuildCategoryBars_Standard)
• All functions return errors explicitly — test both success and error paths
• Zero-value and edge-case coverage (empty maps, nil pointers, zero counts)

Steps

1. Read the target source file to understand the functions to test
2. Read any existing *_test.go file in the same directory for existing helpers and patterns
3. Generate tests covering:
   • Happy path with representative data
   • Edge cases (zero values, empty inputs, nil maps)
   • Error conditions (if the function returns errors)
4. Write or update the *_test.go file
5. Run go test ./path/to/package/... to verify

Example Pattern

func TestFunctionName_Scenario(t *testing.T) {
    tests := []struct {
        name string
        // inputs
        want // expected output
    }{
        {"happy path", /* ... */},
        {"empty input", /* ... */},
        {"edge case", /* ... */},
    }
    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            got := FunctionName(tt.input)
            if got != tt.want {
                t.Errorf("FunctionName(%v) = %v, want %v", tt.input, got, tt.want)
            }
        })
    }
}