add TestDeleteOrder to check that the order of keys is correct after deletion

container/mts/meta/meta_test.go

@@ -251,3 +251,45 @@ func TestEncodeAsString(t *testing.T) {
 		t.Errorf("Did not get expected out. \nGot : %v, \nWant: %v or %v\n", got, want1, want2)
 	}
 }
+
+// TestDeleteOrder checks that the order of keys is correct after a deletion.
+func TestDeleteOrder(t *testing.T) {
+	tests := []struct {
+		delKey string
+		want   []string
+	}{
+		{
+			"key1",
+			[]string{"key2", "key3", "key4"},
+		},
+		{
+			"key2",
+			[]string{"key1", "key3", "key4"},
+		},
+		{
+			"key3",
+			[]string{"key1", "key2", "key4"},
+		},
+		{
+			"key4",
+			[]string{"key1", "key2", "key3"},
+		},
+	}
+
+	for _, test := range tests {
+		t.Logf("deleting %s", test.delKey)
+		meta := NewWith([][2]string{
+			{"key1", "val1"},
+			{"key2", "val2"},
+			{"key3", "val3"},
+			{"key4", "val4"},
+		})
+		meta.Delete(test.delKey)
+
+		got := meta.order
+		want := test.want
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("Did not get expected out. \nGot:  %v, \nWant: %v\n", got, want)
+		}
+	}
+}