Added func ValidateZone

pkg/volume/util.go

@@ -424,3 +424,13 @@ func ZonesToSet(zonesString string) (sets.String, error) {
 	}
 	return zonesSet, nil
 }
+
+// ValidateZone returns:
+// - an error in case zone is an empty string or contains only any combination of spaces and tab characters
+// - nil otherwise
+func ValidateZone(zone string) error {
+	if strings.TrimSpace(zone) == "" {
+		return fmt.Errorf("the provided %q zone is not valid, it's an empty string or contains only spaces and tab characters", zone)
+	}
+	return nil
+}

pkg/volume/util_test.go

@@ -557,3 +557,23 @@ func TestZonesToSet(t *testing.T) {
 		}
 	}
 }
+
+func TestValidateZone(t *testing.T) {
+	functionUnderTest := "ValidateZone"
+
+	// First part: want an error
+	errCases := []string{"", " 	 	 "}
+	for _, errCase := range errCases {
+		if got := ValidateZone(errCase); got == nil {
+			t.Errorf("%v(%v) returned (%v), want (%v)", functionUnderTest, errCase, got, "an error")
+		}
+	}
+
+	// Second part: want no error
+	succCases := []string{" us-east-1a	"}
+	for _, succCase := range succCases {
+		if got := ValidateZone(succCase); got != nil {
+			t.Errorf("%v(%v) returned (%v), want (%v)", functionUnderTest, succCase, got, nil)
+		}
+	}
+}