feat: Report k6 timestamp on k6 execution logs

internal/scraper/scraper.go

@@ -806,6 +806,10 @@ RECORD:
 
 			switch key := dec.Key(); string(key) {
 			case "ts":
+				if !t.IsZero() {
+					continue // already set by the 'time' field
+				}
+
 				var err error
 				t, err = time.Parse(time.RFC3339Nano, string(value))
 				if err != nil {
@@ -816,6 +820,15 @@ RECORD:
 					continue RECORD
 				}
 
+			// k6 sets a 'time' field on its logs using RFC3339; if present, report it instead of the default timestamp
+			case "time":
+				var err error
+				t, err = time.Parse(time.RFC3339, string(value))
+				if err != nil {
+					s.logger.Warn().Err(err).Bytes("value", value).Msg("invalid timestamp scanning logs")
+					continue RECORD
+				}
+
 			default:
 				if err := enc.EncodeKeyval(key, value); err != nil {
 					// We should never hit this because all the entries are valid.

internal/scraper/scraper_test.go

@@ -2035,3 +2035,59 @@ func TestTickWithOffset(t *testing.T) {
 		})
 	}
 }
+
+func TestExtractLogsK6TimeOverridesDefaultTimestamp(t *testing.T) {
+	// Test that k6's "time" field overrides the default "ts" timestamp from the logger
+	testCases := []struct {
+		name         string
+		logs         string
+		sharedLabels []labelPair
+		expected     func(t *testing.T, streams Streams)
+	}{
+		{
+			name: "k6 time field overrides default ts",
+			logs: `ts=2023-06-01T20:00:00Z time="2023-06-01T13:40:26-06:00" level=info msg="k6 message"`,
+			sharedLabels: []labelPair{
+				{name: "probe", value: "test-probe"},
+			},
+			expected: func(t *testing.T, streams Streams) {
+				require.Len(t, streams, 1)
+				require.Len(t, streams[0].Entries, 1)
+				entry := streams[0].Entries[0]
+
+				expectedTime, _ := time.Parse(time.RFC3339, "2023-06-01T13:40:26-06:00")
+				require.Equal(t, expectedTime, entry.Timestamp, "should use k6 time field, not default ts")
+				require.Equal(t, entry.Line, "level=info msg=\"k6 message\"\n")
+			},
+		},
+		{
+			name: "ts field only (no k6 time)",
+			logs: `ts=2023-06-01T20:00:00Z level=info msg="normal message"`,
+			sharedLabels: []labelPair{
+				{name: "probe", value: "test-probe"},
+			},
+			expected: func(t *testing.T, streams Streams) {
+				require.Len(t, streams, 1)
+				require.Len(t, streams[0].Entries, 1)
+				entry := streams[0].Entries[0]
+
+				expectedTime, _ := time.Parse(time.RFC3339Nano, "2023-06-01T20:00:00Z")
+				require.Equal(t, expectedTime, entry.Timestamp)
+				require.Equal(t, entry.Line, "level=info msg=\"normal message\"\n")
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			s := Scraper{
+				logger: testhelper.Logger(t),
+			}
+
+			streams := s.extractLogs(time.Now(), []byte(tc.logs), tc.sharedLabels)
+			tc.expected(t, streams)
+		})
+	}
+}