Seal tracer-provider spans ended before the first end() call

Author: andreiborza

packages/core/src/tracing/sentrySpan.ts

@@ -248,8 +248,12 @@ export class SentrySpan implements Span {
 
   /** @inheritdoc */
   public end(endTimestamp?: SpanTimeInput): void {
-    // If already ended, skip
+    // If already ended, skip the end-of-span processing, but still seal a tracer-provider span. The
+    // seal at the bottom of this method is skipped on this early return, and `_endTime` may have been
+    // set before this first `end()` call (e.g. via the constructor's `endTimestamp`), which would
+    // otherwise leave the span mutable after `end()`. End-of-span processing already ran in that case.
     if (this._endTime) {
+      this._frozen = spanIsTracerProviderSpan(this);
       return;
     }
 

packages/core/test/lib/tracing/sentrySpan.test.ts

@@ -193,6 +193,23 @@ describe('SentrySpan', () => {
       expect(json.start_timestamp).toBe(999);
       expect(json.links).toHaveLength(1);
     });
+
+    it('seals a tracer-provider span that ended via the constructor endTimestamp', () => {
+      // `_endTime` is set in the constructor, so `end()` early-returns before reaching the seal at the
+      // bottom of its body. The span must still be sealed once `end()` is invoked.
+      const span = new SentrySpan({
+        name: 'original',
+        startTimestamp: 1,
+        endTimestamp: 2,
+        attributes: { key: 'before' },
+      });
+      markSpanAsTracerProviderSpan(span);
+
+      span.end();
+
+      span.setAttribute('key', 'after');
+      expect(spanToJSON(span).data?.['key']).toBe('before');
+    });
   });
 
   describe('end', () => {