Add tests for errors in Celery tasks

I noticed there were no tests for the error scenario in the Celery
package. This commit adds a basic test, based on the previous test and
how I see other packages test the error status on the span.

Part of open-telemetry#987

Author: tombruijn

instrumentation/opentelemetry-instrumentation-celery/tests/celery_test_tasks.py

@@ -27,3 +27,7 @@ class Config:
 @app.task
 def task_add(num_a, num_b):
     return num_a + num_b
+
+@app.task
+def task_error():
+    raise Exception("Test exception")

instrumentation/opentelemetry-instrumentation-celery/tests/test_tasks.py

@@ -18,9 +18,9 @@
 from opentelemetry.instrumentation.celery import CeleryInstrumentor
 from opentelemetry.semconv.trace import SpanAttributes
 from opentelemetry.test.test_base import TestBase
-from opentelemetry.trace import SpanKind
+from opentelemetry.trace import SpanKind, StatusCode
 
-from .celery_test_tasks import app, task_add
+from .celery_test_tasks import app, task_add, task_error
 
 
 class TestCeleryInstrumentation(TestBase):
@@ -83,6 +83,54 @@ def test_task(self):
         self.assertEqual(consumer.parent.span_id, producer.context.span_id)
         self.assertEqual(consumer.context.trace_id, producer.context.trace_id)
 
+    def test_task_with_error(self):
+        CeleryInstrumentor().instrument()
+
+        result = task_error.delay()
+
+        timeout = time.time() + 60 * 1  # 1 minutes from now
+        while not result.ready():
+            if time.time() > timeout:
+                break
+            time.sleep(0.05)
+
+        spans = self.sorted_spans(self.memory_exporter.get_finished_spans())
+        self.assertEqual(len(spans), 2)
+
+        consumer, producer = spans
+
+        self.assertEqual(consumer.name, "run/tests.celery_test_tasks.task_error")
+        self.assertEqual(consumer.kind, SpanKind.CONSUMER)
+        self.assertSpanHasAttributes(
+            consumer,
+            {
+                "celery.action": "run",
+                "celery.state": "FAILURE",
+                SpanAttributes.MESSAGING_DESTINATION: "celery",
+                "celery.task_name": "tests.celery_test_tasks.task_error",
+            },
+        )
+        self.assertEqual(consumer.status.status_code, StatusCode.ERROR)
+
+        self.assertEqual(
+            producer.name, "apply_async/tests.celery_test_tasks.task_error"
+        )
+        self.assertEqual(producer.kind, SpanKind.PRODUCER)
+        self.assertSpanHasAttributes(
+            producer,
+            {
+                "celery.action": "apply_async",
+                "celery.task_name": "tests.celery_test_tasks.task_error",
+                SpanAttributes.MESSAGING_DESTINATION_KIND: "queue",
+                SpanAttributes.MESSAGING_DESTINATION: "celery",
+            },
+        )
+        self.assertEqual(producer.status.status_code, StatusCode.UNSET)
+
+        self.assertNotEqual(consumer.parent, producer.context)
+        self.assertEqual(consumer.parent.span_id, producer.context.span_id)
+        self.assertEqual(consumer.context.trace_id, producer.context.trace_id)
+
     def test_uninstrument(self):
         CeleryInstrumentor().instrument()
         CeleryInstrumentor().uninstrument()