fix: [SVLS-8538] apply durable function tags via setTag on the active span (#762)

* fix: [SVLS-8538] apply durable function tags via setTag on the active span

Tags for aws_lambda.durable_function.* were set through options.tags in
tracer.wrap(), but that path does not reliably reach the aws.lambda span.
Apply them directly via span.setTag() in onEndingInvocation(), the same
way http.status_code is applied.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* remove logDebug from durable function tag application

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* add back logDebug for durable function tag application

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: lym953

src/trace/listener.spec.ts

@@ -544,4 +544,28 @@ describe("TraceListener", () => {
       );
     });
   });
+
+  it("sets durable function context tags directly on the aws.lambda span", async () => {
+    const mockSetTag = jest.fn();
+    const mockSpan = { setTag: mockSetTag };
+    const currentSpanSpy = jest.spyOn(TracerWrapper.prototype, "currentSpan", "get").mockReturnValue(mockSpan);
+
+    try {
+      const listener = new TraceListener(defaultConfig);
+      const durableEvent = {
+        DurableExecutionArn:
+          "arn:aws:lambda:us-east-1:123456789012:function:my-func:1/durable-execution/my-execution/550e8400-e29b-41d4-a716-446655440004",
+      };
+      await listener.onStartInvocation(durableEvent, context as any);
+      listener.onEndingInvocation(durableEvent, {}, false);
+
+      expect(mockSetTag).toHaveBeenCalledWith("aws_lambda.durable_function.execution_name", "my-execution");
+      expect(mockSetTag).toHaveBeenCalledWith(
+        "aws_lambda.durable_function.execution_id",
+        "550e8400-e29b-41d4-a716-446655440004",
+      );
+    } finally {
+      currentSpanSpy.mockRestore();
+    }
+  });
 });

src/trace/listener.ts

@@ -226,6 +226,14 @@ export class TraceListener {
         }
       }
     }
+    if (this.durableFunctionContext) {
+      logDebug("Applying durable function context to the aws.lambda span");
+      for (const [key, value] of Object.entries(this.durableFunctionContext)) {
+        if (value !== undefined) {
+          this.tracerWrapper.currentSpan.setTag(key, value);
+        }
+      }
+    }
 
     let rootSpan = this.inferredSpan;
     if (!rootSpan) {
@@ -337,13 +345,6 @@ export class TraceListener {
         ...this.stepFunctionContext,
       };
     }
-    if (this.durableFunctionContext) {
-      logDebug("Applying durable function context to the aws.lambda span");
-      options.tags = {
-        ...options.tags,
-        ...this.durableFunctionContext,
-      };
-    }
     if (this.lambdaSpanParentContext) {
       options.childOf = this.lambdaSpanParentContext;
     }