Fixes response json encoding and add regression test. (#1488)

Also align stream labels alphabetical order with querier.

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

pkg/querier/queryrange/codec.go

@@ -160,7 +160,10 @@ func (codec) EncodeResponse(ctx context.Context, res queryrange.Response) (*http
 	streams := make([]*logproto.Stream, len(proto.Data.Result))
 
 	for i, stream := range proto.Data.Result {
-		streams[i] = &stream
+		streams[i] = &logproto.Stream{
+			Labels:  stream.Labels,
+			Entries: stream.Entries,
+		}
 	}
 	var buf bytes.Buffer
 	if loghttp.Version(proto.Version) == loghttp.VersionLegacy {
@@ -248,7 +251,11 @@ func mergeOrderedNonOverlappingStreams(resps []*LokiResponse, limit uint32, dire
 	for key := range groups {
 		keys = append(keys, key)
 	}
-	sort.Strings(keys)
+	if direction == logproto.BACKWARD {
+		sort.Sort(sort.Reverse(sort.StringSlice(keys)))
+	} else {
+		sort.Strings(keys)
+	}
 
 	// escape hatch, can just return all the streams
 	if total <= int(limit) {

pkg/querier/queryrange/codec_test.go

@@ -307,15 +307,6 @@ func Test_codec_MergeResponse(t *testing.T) {
 				Data: LokiData{
 					ResultType: loghttp.ResultTypeStream,
 					Result: []logproto.Stream{
-						{
-							Labels: `{foo="bar", level="debug"}`,
-							Entries: []logproto.Entry{
-								{Timestamp: time.Unix(0, 16), Line: "16"},
-								{Timestamp: time.Unix(0, 15), Line: "15"},
-								{Timestamp: time.Unix(0, 6), Line: "6"},
-								{Timestamp: time.Unix(0, 5), Line: "5"},
-							},
-						},
 						{
 							Labels: `{foo="bar", level="error"}`,
 							Entries: []logproto.Entry{
@@ -326,6 +317,15 @@ func Test_codec_MergeResponse(t *testing.T) {
 								{Timestamp: time.Unix(0, 1), Line: "1"},
 							},
 						},
+						{
+							Labels: `{foo="bar", level="debug"}`,
+							Entries: []logproto.Entry{
+								{Timestamp: time.Unix(0, 16), Line: "16"},
+								{Timestamp: time.Unix(0, 15), Line: "15"},
+								{Timestamp: time.Unix(0, 6), Line: "6"},
+								{Timestamp: time.Unix(0, 5), Line: "5"},
+							},
+						},
 					},
 				},
 			},
@@ -395,17 +395,17 @@ func Test_codec_MergeResponse(t *testing.T) {
 					ResultType: loghttp.ResultTypeStream,
 					Result: []logproto.Stream{
 						{
-							Labels: `{foo="bar", level="debug"}`,
+							Labels: `{foo="bar", level="error"}`,
 							Entries: []logproto.Entry{
-								{Timestamp: time.Unix(0, 16), Line: "16"},
-								{Timestamp: time.Unix(0, 15), Line: "15"},
+								{Timestamp: time.Unix(0, 10), Line: "10"},
+								{Timestamp: time.Unix(0, 9), Line: "9"},
 							},
 						},
 						{
-							Labels: `{foo="bar", level="error"}`,
+							Labels: `{foo="bar", level="debug"}`,
 							Entries: []logproto.Entry{
-								{Timestamp: time.Unix(0, 10), Line: "10"},
-								{Timestamp: time.Unix(0, 9), Line: "9"},
+								{Timestamp: time.Unix(0, 16), Line: "16"},
+								{Timestamp: time.Unix(0, 15), Line: "15"},
 							},
 						},
 					},
@@ -669,11 +669,19 @@ var (
 					"values":[
 						[ "123456789012345", "super line" ]
 					]
+				},
+				{
+					"stream": {
+						"test": "test2"
+					},
+					"values":[
+						[ "123456789012346", "super line2" ]
+					]
 				}
 			]
 		}
 	}`
-	streamsStringLegacy = `{"streams":[{"labels":"{test=\"test\"}","entries":[{"ts":"1970-01-02T10:17:36.789012345Z","line":"super line"}]}]}`
+	streamsStringLegacy = `{"streams":[{"labels":"{test=\"test\"}","entries":[{"ts":"1970-01-02T10:17:36.789012345Z","line":"super line"}]},{"labels":"{test=\"test2\"}","entries":[{"ts":"1970-01-02T10:17:36.789012346Z","line":"super line2"}]}]}`
 	logStreams          = []logproto.Stream{
 		{
 			Labels: `{test="test"}`,
@@ -684,6 +692,15 @@ var (
 				},
 			},
 		},
+		{
+			Labels: `{test="test2"}`,
+			Entries: []logproto.Entry{
+				{
+					Line:      "super line2",
+					Timestamp: time.Unix(0, 123456789012346).UTC(),
+				},
+			},
+		},
 	}
 )