feat(envelope-item): Support metric type (#4956)

* add trace metric envelope type

* changelog id

* fix lint

* lint

* update test with incorrect key

* update api

---------

Co-authored-by: Lucas <luca-zimerman1@hotmail.com>

Author: lucas-zimerman

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Internal
+
+- Support `metric` envelope item type ([#4956](https://github.com/getsentry/sentry-java/pull/4956))
+
 ## 8.28.0
 
 ### Features

sentry/api/sentry.api

@@ -362,6 +362,7 @@ public final class io/sentry/DataCategory : java/lang/Enum {
 	public static final field Security Lio/sentry/DataCategory;
 	public static final field Session Lio/sentry/DataCategory;
 	public static final field Span Lio/sentry/DataCategory;
+	public static final field TraceMetric Lio/sentry/DataCategory;
 	public static final field Transaction Lio/sentry/DataCategory;
 	public static final field Unknown Lio/sentry/DataCategory;
 	public static final field UserReport Lio/sentry/DataCategory;
@@ -3138,6 +3139,7 @@ public final class io/sentry/SentryItemType : java/lang/Enum, io/sentry/JsonSeri
 	public static final field ReplayVideo Lio/sentry/SentryItemType;
 	public static final field Session Lio/sentry/SentryItemType;
 	public static final field Span Lio/sentry/SentryItemType;
+	public static final field TraceMetric Lio/sentry/SentryItemType;
 	public static final field Transaction Lio/sentry/SentryItemType;
 	public static final field Unknown Lio/sentry/SentryItemType;
 	public static final field UserFeedback Lio/sentry/SentryItemType;

sentry/src/main/java/io/sentry/DataCategory.java

@@ -11,6 +11,7 @@ public enum DataCategory {
   Attachment("attachment"),
   LogItem("log_item"),
   LogByte("log_byte"),
+  TraceMetric("trace_metric"),
   Monitor("monitor"),
   Profile("profile"),
   ProfileChunkUi("profile_chunk_ui"),

sentry/src/main/java/io/sentry/SentryItemType.java

@@ -23,6 +23,7 @@ public enum SentryItemType implements JsonSerializable {
   CheckIn("check_in"),
   Feedback("feedback"),
   Log("log"),
+  TraceMetric("trace_metric"),
   Span("span"),
   Unknown("__unknown__"); // DataCategory.Unknown
 

sentry/src/main/java/io/sentry/clientreport/ClientReportRecorder.java

@@ -218,6 +218,9 @@ private DataCategory categoryFromItemType(SentryItemType itemType) {
     if (SentryItemType.Span.equals(itemType)) {
       return DataCategory.Span;
     }
+    if (SentryItemType.TraceMetric.equals(itemType)) {
+      return DataCategory.TraceMetric;
+    }
 
     return DataCategory.Default;
   }

sentry/src/main/java/io/sentry/transport/RateLimiter.java

@@ -215,6 +215,8 @@ private boolean isRetryAfter(final @NotNull String itemType) {
         return Collections.singletonList(DataCategory.LogItem);
       case "span":
         return Collections.singletonList(DataCategory.Span);
+      case "trace_metric":
+        return Collections.singletonList(DataCategory.TraceMetric);
       default:
         return Collections.singletonList(DataCategory.Unknown);
     }

sentry/src/test/java/io/sentry/protocol/SentryItemTypeSerializationTest.kt

@@ -33,6 +33,7 @@ class SentryItemTypeSerializationTest {
     assertEquals(serialize(SentryItemType.CheckIn), json("check_in"))
     assertEquals(serialize(SentryItemType.Feedback), json("feedback"))
     assertEquals(serialize(SentryItemType.Span), json("span"))
+    assertEquals(serialize(SentryItemType.TraceMetric), json("trace_metric"))
   }
 
   @Test
@@ -51,6 +52,7 @@ class SentryItemTypeSerializationTest {
     assertEquals(deserialize(json("check_in")), SentryItemType.CheckIn)
     assertEquals(deserialize(json("feedback")), SentryItemType.Feedback)
     assertEquals(deserialize(json("span")), SentryItemType.Span)
+    assertEquals(deserialize(json("trace_metric")), SentryItemType.TraceMetric)
   }
 
   private fun json(type: String): String = "{\"type\":\"${type}\"}"

sentry/src/test/java/io/sentry/transport/RateLimiterTest.kt

@@ -563,6 +563,33 @@ class RateLimiterTest {
     verifyNoMoreInteractions(fixture.clientReportRecorder)
   }
 
+  @Test
+  fun `drop trace metric items as lost`() {
+    val rateLimiter = fixture.getSUT()
+
+    // There is no span API yet so we'll create the envelope manually using EnvelopeReader
+    // This mimics how hybrid SDKs would send trace_metric envelope items
+    val spanPayload = """{"items":[]}"""
+    val metricItemHeader =
+      """{"type":"trace_metric","length":${spanPayload.length},"content_type":"application/vnd.sentry.items.trace-metric+json","item_count":1}"""
+    val envelopeHeader = """{}"""
+    val rawEnvelope = "$envelopeHeader\n$metricItemHeader\n$spanPayload"
+
+    val options = SentryOptions()
+    val envelopeReader = EnvelopeReader(JsonSerializer(options))
+    val metricEnvelope = envelopeReader.read(rawEnvelope.byteInputStream())!!
+    val metricItem = metricEnvelope.items.first()
+
+    rateLimiter.updateRetryAfterLimits("60:trace_metric:key", null, 1)
+    val result = rateLimiter.filter(metricEnvelope, Hint())
+
+    assertNull(result)
+
+    verify(fixture.clientReportRecorder, times(1))
+      .recordLostEnvelopeItem(eq(DiscardReason.RATELIMIT_BACKOFF), same(metricItem))
+    verifyNoMoreInteractions(fixture.clientReportRecorder)
+  }
+
   @Test
   fun `apply rate limits notifies observers`() {
     val rateLimiter = fixture.getSUT()