kubernetes/test/utils/harness/harness.go

type Harness …

// For creates a Harness from a testing.T
// Callers must call Close on the Harness so that resources can be cleaned up
func For(t *testing.T) *Harness { … }

// Close cleans up any owned resources, and should be called in a defer block after For
func (h *Harness) Close() { … }

// TempDir is a wrapper around os.MkdirTemp for tests.
// It automatically fails the test if we can't create a temp file,
// and deletes the temp directory when Close is called on the Harness
func (h *Harness) TempDir(baseDir string, prefix string) string { … }