From 8708de4a735f8ca08afebf1487924e0803906ba8 Mon Sep 17 00:00:00 2001
From: Anant Sharma <anant.sharma@grafana.com>
Date: Mon, 1 Dec 2025 16:54:19 -0500
Subject: [PATCH] feat: Report k6 timestamp on k6 execution logs

Uses the timestamp reported by k6 during the execution of scripted checks as
the Timestamp for Loki logs, rather than the current timestamp at the time
of extraction.
---
 internal/scraper/scraper.go      | 13 ++++++++
 internal/scraper/scraper_test.go | 56 ++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+)

diff --git a/internal/scraper/scraper.go b/internal/scraper/scraper.go
index 87c60d5b1..1245c7e3b 100644
--- a/internal/scraper/scraper.go
+++ b/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.
diff --git a/internal/scraper/scraper_test.go b/internal/scraper/scraper_test.go
index ec1ce2dc2..15c0babb1 100644
--- a/internal/scraper/scraper_test.go
+++ b/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)
+		})
+	}
+}