fix(router.py): enable fallbacks for sync completions

litellm/tests/test_router_fallbacks.py

@@ -0,0 +1,76 @@
+#### What this tests ####
+#    This tests calling router with fallback models 
+
+import sys, os, time
+import traceback, asyncio
+import pytest
+sys.path.insert(
+    0, os.path.abspath("../..")
+)  # Adds the parent directory to the system path
+
+import litellm
+from litellm import Router
+
+model_list = [
+    { # list of model deployments 
+		"model_name": "azure/gpt-3.5-turbo", # openai model name 
+		"litellm_params": { # params for litellm completion/embedding call 
+			"model": "azure/chatgpt-v-2", 
+			"api_key": "bad-key",
+			"api_version": os.getenv("AZURE_API_VERSION"),
+			"api_base": os.getenv("AZURE_API_BASE")
+		},
+		"tpm": 240000,
+		"rpm": 1800
+	}, 
+	{
+		"model_name": "azure/gpt-3.5-turbo", # openai model name 
+		"litellm_params": { # params for litellm completion/embedding call 
+			"model": "azure/chatgpt-functioncalling", 
+			"api_key": "bad-key",
+			"api_version": os.getenv("AZURE_API_VERSION"),
+			"api_base": os.getenv("AZURE_API_BASE")
+		},
+		"tpm": 240000,
+		"rpm": 1800
+	}, 
+	{
+		"model_name": "gpt-3.5-turbo", # openai model name 
+		"litellm_params": { # params for litellm completion/embedding call 
+			"model": "gpt-3.5-turbo", 
+			"api_key": os.getenv("OPENAI_API_KEY"),
+		},
+		"tpm": 1000000,
+		"rpm": 9000
+	}
+]
+
+
+
+router = Router(model_list=model_list, fallbacks=[{"azure/gpt-3.5-turbo": ["gpt-3.5-turbo"]}])
+
+kwargs = {"model": "azure/gpt-3.5-turbo", "messages": [{"role": "user", "content":"Hey, how's it going?"}]}
+
+def test_sync_fallbacks():        
+    try:
+        response = router.completion(**kwargs)
+        print(f"response: {response}")
+    except Exception as e:
+        print(e)
+
+def test_async_fallbacks(): 
+    async def test_get_response():
+        user_message = "Hello, how are you?"
+        messages = [{"content": user_message, "role": "user"}]
+        try:
+            response = await router.acompletion(**kwargs)
+            # response = await response
+            print(f"response: {response}")
+        except litellm.Timeout as e: 
+            pass
+        except Exception as e:
+            pytest.fail(f"An exception occurred: {e}")
+
+    asyncio.run(test_get_response())
+
+test_async_fallbacks()