diff --git a/envutil/info_test.go b/envutil/info_test.go
index 20ebcd768..ca9243f08 100644
--- a/envutil/info_test.go
+++ b/envutil/info_test.go
@@ -51,10 +51,11 @@ func TestIsConsole(t *testing.T) {
 func TestIsSupportColor(t *testing.T) {
 	is := assert.New(t)
 
+	// clear all OS env
+	testutil.ClearOSEnv()
+	defer testutil.RevertOSEnv()
+
 	// IsSupport256Color
-	oldVal := os.Getenv("TERM")
-	_ = os.Unsetenv("TERM")
-	// is.False(envutil.IsSupportColor())
 	is.False(envutil.IsSupport256Color())
 
 	// ConEmuANSI
@@ -85,10 +86,4 @@ func TestIsSupportColor(t *testing.T) {
 
 	is.NoErr(os.Setenv("TERM", "xterm-vt220"))
 	is.True(envutil.IsSupportColor())
-	// revert
-	if oldVal != "" {
-		is.NoErr(os.Setenv("TERM", oldVal))
-	} else {
-		is.NoErr(os.Unsetenv("TERM"))
-	}
 }
diff --git a/stdutil/convert_test.go b/stdutil/convert_test.go
index 89eb7ae3b..9d2247477 100644
--- a/stdutil/convert_test.go
+++ b/stdutil/convert_test.go
@@ -15,7 +15,7 @@ func TestMustString(t *testing.T) {
 
 	assert.PanicsErrMsg(t, func() {
 		stdutil.MustString([]string{"a", "b"})
-	}, "convert data type is failure")
+	}, comdef.ErrConvType.Error())
 }
 
 func TestToString(t *testing.T) {
diff --git a/testutil/envmock.go b/testutil/envmock.go
index ecff8ce24..4604b2dfb 100644
--- a/testutil/envmock.go
+++ b/testutil/envmock.go
@@ -77,13 +77,32 @@ func MockOsEnv(mp map[string]string, fn func()) {
 	MockCleanOsEnv(mp, fn)
 }
 
+// backup os ENV
+var envBak = os.Environ()
+
+// ClearOSEnv info.
+//
+// Usage:
+//
+//	testutil.ClearOSEnv()
+//	defer testutil.RevertOSEnv()
+//	// do something ...
+func ClearOSEnv() { os.Clearenv() }
+
+// RevertOSEnv info
+func RevertOSEnv() {
+	os.Clearenv()
+	for _, str := range envBak {
+		nodes := strings.SplitN(str, "=", 2)
+		_ = os.Setenv(nodes[0], nodes[1])
+	}
+}
+
 // MockCleanOsEnv by env map data.
 //
 // will clear all old ENV data, use given data map.
 // will recover old ENV after fn run.
 func MockCleanOsEnv(mp map[string]string, fn func()) {
-	envBak := os.Environ()
-
 	os.Clearenv()
 	for key, val := range mp {
 		_ = os.Setenv(key, val)