From 6a91dc382a554605379dd45df988922e900f409b Mon Sep 17 00:00:00 2001
From: Eunbin Son <thswlsqls@naver.com>
Date: Sun, 21 Jun 2026 18:13:02 +0900
Subject: [PATCH] Preserve OpenCensus status description when converting to
 OpenTelemetry

---
 CHANGELOG.md                                  |  4 ++
 .../opencensusshim/OpenTelemetrySpanImpl.java |  8 ++-
 .../OpenTelemetrySpanImplTest.java            | 50 +++++++++++++++++++
 3 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 opencensus-shim/src/test/java/io/opentelemetry/opencensusshim/OpenTelemetrySpanImplTest.java

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c399e74acfa..8ff72ada7ac 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Shims
+
+* OpenCensus: Preserve status description when converting a span status to OpenTelemetry
+
 ## Version 1.63.0 (2026-06-05)
 
 ### API
diff --git a/opencensus-shim/src/main/java/io/opentelemetry/opencensusshim/OpenTelemetrySpanImpl.java b/opencensus-shim/src/main/java/io/opentelemetry/opencensusshim/OpenTelemetrySpanImpl.java
index 8d25f722786..87c41b1ff07 100644
--- a/opencensus-shim/src/main/java/io/opentelemetry/opencensusshim/OpenTelemetrySpanImpl.java
+++ b/opencensus-shim/src/main/java/io/opentelemetry/opencensusshim/OpenTelemetrySpanImpl.java
@@ -123,7 +123,13 @@ public void addMessageEvent(MessageEvent messageEvent) {
   @Override
   public void setStatus(Status status) {
     Preconditions.checkNotNull(status, "status");
-    DelegatingSpan.super.setStatus(status.isOk() ? StatusCode.OK : StatusCode.ERROR);
+    StatusCode code = status.isOk() ? StatusCode.OK : StatusCode.ERROR;
+    String description = status.getDescription();
+    if (description == null) {
+      DelegatingSpan.super.setStatus(code);
+    } else {
+      DelegatingSpan.super.setStatus(code, description);
+    }
   }
 
   @Override
diff --git a/opencensus-shim/src/test/java/io/opentelemetry/opencensusshim/OpenTelemetrySpanImplTest.java b/opencensus-shim/src/test/java/io/opentelemetry/opencensusshim/OpenTelemetrySpanImplTest.java
new file mode 100644
index 00000000000..448c032a3f8
--- /dev/null
+++ b/opencensus-shim/src/test/java/io/opentelemetry/opencensusshim/OpenTelemetrySpanImplTest.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.opencensusshim;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import io.opencensus.trace.Status;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.SpanContext;
+import io.opentelemetry.api.trace.StatusCode;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.mockito.junit.jupiter.MockitoSettings;
+import org.mockito.quality.Strictness;
+
+@ExtendWith(MockitoExtension.class)
+@MockitoSettings(strictness = Strictness.LENIENT)
+class OpenTelemetrySpanImplTest {
+
+  @Mock private Span otelSpan;
+
+  private OpenTelemetrySpanImpl shimSpan() {
+    when(otelSpan.getSpanContext()).thenReturn(SpanContext.getInvalid());
+    return new OpenTelemetrySpanImpl(otelSpan);
+  }
+
+  @Test
+  void setStatus_preservesDescription() {
+    shimSpan().setStatus(Status.UNKNOWN.withDescription("connection refused"));
+
+    verify(otelSpan).setStatus(StatusCode.ERROR, "connection refused");
+  }
+
+  @Test
+  void setStatus_withoutDescription_setsCodeOnly() {
+    shimSpan().setStatus(Status.OK);
+
+    verify(otelSpan).setStatus(StatusCode.OK);
+    verify(otelSpan, never()).setStatus(any(StatusCode.class), anyString());
+  }
+}