From 640e2d41059346c0ae40205cb6ece878f74ff2e7 Mon Sep 17 00:00:00 2001
From: Alexander Dinauer <alexander.dinauer@sentry.io>
Date: Fri, 19 Dec 2025 13:26:00 +0100
Subject: [PATCH] Record client report for discarded metrics envelope item

---
 .../clientreport/ClientReportRecorder.java    | 15 +++++++++
 .../sentry/clientreport/ClientReportTest.kt   | 32 +++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/sentry/src/main/java/io/sentry/clientreport/ClientReportRecorder.java b/sentry/src/main/java/io/sentry/clientreport/ClientReportRecorder.java
index eccf311cf83..0180b16977d 100644
--- a/sentry/src/main/java/io/sentry/clientreport/ClientReportRecorder.java
+++ b/sentry/src/main/java/io/sentry/clientreport/ClientReportRecorder.java
@@ -8,6 +8,8 @@
 import io.sentry.SentryLevel;
 import io.sentry.SentryLogEvent;
 import io.sentry.SentryLogEvents;
+import io.sentry.SentryMetricsEvent;
+import io.sentry.SentryMetricsEvents;
 import io.sentry.SentryOptions;
 import io.sentry.protocol.SentrySpan;
 import io.sentry.protocol.SentryTransaction;
@@ -115,6 +117,19 @@ public void recordLostEnvelopeItem(
           } else {
             options.getLogger().log(SentryLevel.ERROR, "Unable to parse lost logs envelope item.");
           }
+        } else if (itemCategory.equals(DataCategory.TraceMetric)) {
+          final @Nullable SentryMetricsEvents metrics =
+              envelopeItem.getMetrics(options.getSerializer());
+          if (metrics != null) {
+            final @NotNull List<SentryMetricsEvent> items = metrics.getItems();
+            final long count = items.size();
+            recordLostEventInternal(reason.getReason(), itemCategory.getCategory(), count);
+            executeOnDiscard(reason, itemCategory, count);
+          } else {
+            options
+                .getLogger()
+                .log(SentryLevel.ERROR, "Unable to parse lost metrics envelope item.");
+          }
         } else {
           recordLostEventInternal(reason.getReason(), itemCategory.getCategory(), 1L);
           executeOnDiscard(reason, itemCategory, 1L);
diff --git a/sentry/src/test/java/io/sentry/clientreport/ClientReportTest.kt b/sentry/src/test/java/io/sentry/clientreport/ClientReportTest.kt
index ae4a5f35362..95639d8c581 100644
--- a/sentry/src/test/java/io/sentry/clientreport/ClientReportTest.kt
+++ b/sentry/src/test/java/io/sentry/clientreport/ClientReportTest.kt
@@ -20,6 +20,8 @@ import io.sentry.SentryLogEvent
 import io.sentry.SentryLogEvents
 import io.sentry.SentryLogLevel
 import io.sentry.SentryLongDate
+import io.sentry.SentryMetricsEvent
+import io.sentry.SentryMetricsEvents
 import io.sentry.SentryOptions
 import io.sentry.SentryReplayEvent
 import io.sentry.SentryTracer
@@ -382,6 +384,36 @@ class ClientReportTest {
     assertEquals(226, logByte.quantity)
   }
 
+  @Test
+  fun `recording lost client report counts metric entries`() {
+    val onDiscardMock = mock<SentryOptions.OnDiscardCallback>()
+    givenClientReportRecorder { options -> options.onDiscard = onDiscardMock }
+
+    val envelope =
+      testHelper.newEnvelope(
+        SentryEnvelopeItem.fromMetrics(
+          opts.serializer,
+          SentryMetricsEvents(
+            listOf(
+              SentryMetricsEvent(SentryId(), SentryLongDate(1), "metric1", "counter", 1.0),
+              SentryMetricsEvent(SentryId(), SentryLongDate(2), "metric2", "gauge", 2.0),
+              SentryMetricsEvent(SentryId(), SentryLongDate(3), "metric3", "distribution", 3.0),
+            )
+          ),
+        )
+      )
+
+    clientReportRecorder.recordLostEnvelopeItem(DiscardReason.NETWORK_ERROR, envelope.items.first())
+
+    verify(onDiscardMock, times(1))
+      .execute(DiscardReason.NETWORK_ERROR, DataCategory.TraceMetric, 3)
+
+    val clientReport = clientReportRecorder.resetCountsAndGenerateClientReport()
+    val metricItem =
+      clientReport!!.discardedEvents!!.first { it.category == DataCategory.TraceMetric.category }
+    assertEquals(3, metricItem.quantity)
+  }
+
   private fun givenClientReportRecorder(
     callback: Sentry.OptionsConfiguration<SentryOptions>? = null
   ) {