add streaming test

tests/test_salesgpt.py

@@ -39,4 +39,37 @@ def test_valid_inference(self, load_env):
 
 
     def test_valid_inference_stream(self, load_env):
-        pass
+        """Test that the agent will start and generate the first utterance when streaming."""
+
+        llm = ChatOpenAI(temperature=0.9)
+        model_name = 'gpt-3.5-turbo'
+
+        sales_agent = SalesGPT.from_llm(
+            llm,
+            verbose=False,
+            salesperson_name="Ted Lasso",
+            salesperson_role="Sales Representative",
+            company_name="Sleep Haven",
+            company_business="""Sleep Haven 
+                                    is a premium mattress company that provides
+                                    customers with the most comfortable and
+                                    supportive sleeping experience possible. 
+                                    We offer a range of high-quality mattresses,
+                                    pillows, and bedding accessories 
+                                    that are designed to meet the unique 
+                                    needs of our customers.""",
+        )
+
+        sales_agent.seed_agent()
+        sales_agent.determine_conversation_stage()  # optional for demonstration, built into the prompt
+
+        # agent output sample
+        stream_generator = sales_agent.step(return_streaming_generator=True, model_name=model_name)
+        agent_output=''
+        for chunk in stream_generator:
+            token = chunk["choices"][0]["delta"].get("content", "")
+            agent_output += token
+
+        assert agent_output is not None, "Agent output cannot be None."
+        assert isinstance(agent_output, str), "Agent output needs to be of type str"
+        assert len(agent_output) > 0, "Length of output needs to be greater than 0."