Default severity: warning
Before Go 1.15, a custom TestMain that called testing.M.Run had to pass its
result to os.Exit or failed tests could appear successful. Go 1.15 and newer
propagate the returned status automatically, so the check is silent there.
Bad
func TestMain(m *testing.M) { m.Run() }Good
func TestMain(m *testing.M) { os.Exit(m.Run()) }