fix(fastapi-instrumentation): fix tests and finalize memory leak fix

Author: artemziborev

instrumentation/opentelemetry-instrumentation-fastapi/src/opentelemetry/instrumentation/fastapi/__init__.py

@@ -392,7 +392,11 @@ def _instrument(self, **kwargs):
         fastapi.FastAPI = _InstrumentedFastAPI
 
     def _uninstrument(self, **kwargs):
-        for instance in _InstrumentedFastAPI._instrumented_fastapi_apps:
+        # Create a copy of the set to avoid RuntimeError during iteration
+        instances_to_uninstrument = list(
+            _InstrumentedFastAPI._instrumented_fastapi_apps
+        )
+        for instance in instances_to_uninstrument:
             self.uninstrument_app(instance)
         _InstrumentedFastAPI._instrumented_fastapi_apps.clear()
         fastapi.FastAPI = self._original_fastapi

instrumentation/opentelemetry-instrumentation-fastapi/tests/test_fastapi_memory_leak.py

@@ -19,12 +19,20 @@
 
 from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor
 
+# Check if sys.getrefcount is available (not available in PyPy)
+HAS_GETREFCOUNT = hasattr(sys, "getrefcount")
+
 
 class TestFastAPIMemoryLeak(unittest.TestCase):
     """Test for memory leak in FastAPIInstrumentor.uninstrument_app()"""
 
     def test_refcount_after_uninstrument(self):
         """Test that refcount is restored after uninstrument_app()"""
+        if not HAS_GETREFCOUNT:
+            self.skipTest(
+                "sys.getrefcount not available in this Python implementation"
+            )
+
         app = fastapi.FastAPI()
 
         # Instrument the app
@@ -53,6 +61,11 @@ def test_refcount_after_uninstrument(self):
 
     def test_multiple_instrument_uninstrument_cycles(self):
         """Test that multiple instrument/uninstrument cycles don't leak memory"""
+        if not HAS_GETREFCOUNT:
+            self.skipTest(
+                "sys.getrefcount not available in this Python implementation"
+            )
+
         app = fastapi.FastAPI()
 
         initial_refcount = sys.getrefcount(app)
@@ -84,6 +97,11 @@ def test_multiple_instrument_uninstrument_cycles(self):
 
     def test_multiple_apps_instrument_uninstrument(self):
         """Test that multiple apps can be instrumented and uninstrumented without leaks"""
+        if not HAS_GETREFCOUNT:
+            self.skipTest(
+                "sys.getrefcount not available in this Python implementation"
+            )
+
         apps = [fastapi.FastAPI() for _ in range(3)]
         initial_refcounts = [sys.getrefcount(app) for app in apps]