Package goldentest is a utility to help create tests that compare a result (e.g. serialized data
or formatted text) against a golden file stored in testdata.
func Check(t *testing.T, rerunCmd, goldenPath, actual string)
Check looks for a file at goldenPath, compares actual against the content, and causes the test to
fail if it's incorrect. If "-update" is passed to the "go test" command, instead of failing, it
writes actual to goldenPath.