monitoring: some bug fix

Signed-off-by: huanggze <loganhuang@yunify.com>

pkg/models/monitoring/expressions/prometheus_test.go

@@ -0,0 +1,51 @@
+package expressions
+
+import (
+	"fmt"
+	"github.com/google/go-cmp/cmp"
+	"testing"
+)
+
+func TestLabelReplace(t *testing.T) {
+	tests := []struct {
+		expr        string
+		expected    string
+		expectedErr bool
+	}{
+		{
+			expr:        "up",
+			expected:    `up{namespace="default"}`,
+			expectedErr: false,
+		},
+		{
+			expr:        `up{namespace="random"}`,
+			expected:    `up{namespace="default"}`,
+			expectedErr: false,
+		},
+		{
+			expr:        `up{namespace="random"} + up{job="test"}`,
+			expected:    `up{namespace="default"} + up{job="test",namespace="default"}`,
+			expectedErr: false,
+		},
+		{
+			expr:        `@@@@`,
+			expectedErr: true,
+		},
+	}
+
+	for i, tt := range tests {
+		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+			result, err := labelReplace(tt.expr, "default")
+			if err != nil {
+				if !tt.expectedErr {
+					t.Fatal(err)
+				}
+				return
+			}
+
+			if diff := cmp.Diff(result, tt.expected); diff != "" {
+				t.Fatalf("%T differ (-got, +want): %s", tt.expected, diff)
+			}
+		})
+	}
+}