Create test_set_api_key_fix.py

Author: DanielHashmi

tests/tracing/test_set_api_key_fix.py

@@ -0,0 +1,32 @@
+import os
+
+from agents.tracing.processors import BackendSpanExporter
+
+
+def test_set_api_key_preserves_env_fallback():
+    """Test that set_api_key doesn't break environment variable fallback."""
+    # Set up environment
+    original_key = os.environ.get("OPENAI_API_KEY")
+    os.environ["OPENAI_API_KEY"] = "env-key"
+
+    try:
+        exporter = BackendSpanExporter()
+
+        # Initially should use env var
+        assert exporter.api_key == "env-key"
+
+        # Set explicit key
+        exporter.set_api_key("explicit-key")
+        assert exporter.api_key == "explicit-key"
+
+        # Clear explicit key and verify env fallback works
+        exporter._api_key = None
+        if "api_key" in exporter.__dict__:
+            del exporter.__dict__["api_key"]
+        assert exporter.api_key == "env-key"
+
+    finally:
+        if original_key is None:
+            os.environ.pop("OPENAI_API_KEY", None)
+        else:
+            os.environ["OPENAI_API_KEY"] = original_key