TestLabelValuesWithMatchers: Add test case

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

tsdb/block_test.go

@@ -235,6 +235,13 @@ func TestLabelValuesWithMatchers(t *testing.T) {
 	require.NoError(t, err)
 	defer func() { require.NoError(t, indexReader.Close()) }()
 
+	var uniqueWithout30s []string
+	for i := 0; i < 100; i++ {
+		if i/10 != 3 {
+			uniqueWithout30s = append(uniqueWithout30s, fmt.Sprintf("value%d", i))
+		}
+	}
+	sort.Strings(uniqueWithout30s)
 	testCases := []struct {
 		name           string
 		labelName      string
@@ -261,6 +268,14 @@ func TestLabelValuesWithMatchers(t *testing.T) {
 			labelName:      "tens",
 			matchers:       []*labels.Matcher{labels.MustNewMatcher(labels.MatchNotEqual, "unique", "")},
 			expectedValues: []string{"value0", "value1", "value2", "value3", "value4", "value5", "value6", "value7", "value8", "value9"},
+		}, {
+			name:      "get unique IDs based on tens not being equal to a certain value, while not empty",
+			labelName: "unique",
+			matchers: []*labels.Matcher{
+				labels.MustNewMatcher(labels.MatchNotEqual, "tens", "value3"),
+				labels.MustNewMatcher(labels.MatchNotEqual, "tens", ""),
+			},
+			expectedValues: uniqueWithout30s,
 		},
 	}