Fix #2698: Implement MCP SSE server connection for tools

Co-Authored-By: Joe Moura <joao@crewai.com>

tests/utilities/test_sse_client.py

@@ -0,0 +1,100 @@
+import json
+import unittest
+from unittest.mock import MagicMock, patch
+
+import pytest
+import requests
+import sseclient
+
+from crewai.utilities.sse_client import (
+    SSEClient,
+    SSEConnectionErrorEvent,
+    SSEConnectionStartedEvent,
+    SSEMessageReceivedEvent,
+)
+
+
+class TestSSEClient(unittest.TestCase):
+    def setUp(self):
+        self.base_url = "https://test.example.com"
+        self.endpoint = "/events"
+        self.headers = {"Authorization": "Bearer test-token"}
+        self.sse_client = SSEClient(
+            base_url=self.base_url,
+            endpoint=self.endpoint,
+            headers=self.headers
+        )
+
+    @patch("crewai.utilities.events.crewai_event_bus.emit")
+    @patch("requests.get")
+    @patch("sseclient.SSEClient")
+    def test_connect_success(self, mock_sse_client, mock_get, mock_emit):
+        mock_response = MagicMock()
+        mock_get.return_value = mock_response
+        
+        self.sse_client.connect()
+        
+        mock_get.assert_called_once_with(
+            "https://test.example.com/events",
+            headers=self.headers,
+            stream=True,
+            timeout=30
+        )
+        mock_response.raise_for_status.assert_called_once()
+        mock_sse_client.assert_called_once_with(mock_response)
+        mock_emit.assert_called_once()
+        event = mock_emit.call_args[1]["event"]
+        assert isinstance(event, SSEConnectionStartedEvent)
+        assert event.endpoint == "https://test.example.com/events"
+        assert event.headers == self.headers
+
+    @patch("crewai.utilities.events.crewai_event_bus.emit")
+    @patch("requests.get")
+    def test_connect_error(self, mock_get, mock_emit):
+        mock_get.side_effect = requests.exceptions.RequestException("Connection error")
+        
+        with pytest.raises(requests.exceptions.RequestException):
+            self.sse_client.connect()
+        
+        mock_emit.assert_called_once()
+        event = mock_emit.call_args[1]["event"]
+        assert isinstance(event, SSEConnectionErrorEvent)
+        assert event.endpoint == "https://test.example.com/events"
+        assert "Connection error" in event.error
+
+    @patch("crewai.utilities.events.crewai_event_bus.emit")
+    @patch("requests.get")
+    def test_listen_with_handlers(self, mock_get, mock_emit):
+        mock_response = MagicMock()
+        mock_get.return_value = mock_response
+        
+        mock_sse_client = MagicMock()
+        mock_event1 = MagicMock(event="test_event", data='{"key": "value"}')
+        mock_event2 = MagicMock(event="message", data="plain text")
+        mock_sse_client.__iter__.return_value = [mock_event1, mock_event2]
+        
+        self.sse_client._client = mock_sse_client
+        
+        test_event_handler = MagicMock()
+        message_handler = MagicMock()
+        
+        event_handlers = {
+            "test_event": test_event_handler,
+            "message": message_handler
+        }
+        self.sse_client.listen(event_handlers)
+        
+        test_event_handler.assert_called_once_with({"key": "value"})
+        message_handler.assert_called_once_with("plain text")
+        
+        assert mock_emit.call_count == 2
+        event1 = mock_emit.call_args_list[0][1]["event"]
+        event2 = mock_emit.call_args_list[1][1]["event"]
+        
+        assert isinstance(event1, SSEMessageReceivedEvent)
+        assert event1.event == "test_event"
+        assert event1.data == {"key": "value"}
+        
+        assert isinstance(event2, SSEMessageReceivedEvent)
+        assert event2.event == "message"
+        assert event2.data == "plain text"