feat: allow passing a Component to the set method (#3597)

* refactor: Add _find_matching_output_method to Component class

* feat: allow components to be passed in set method

* fix: Add test for graph set method with valid component

* set value variable to the output callable

* refactor: Update test_component.py to use set_component method

This commit refactors the test_component.py file in the custom_component directory. The test_set_invalid_input() function has been renamed to test_set_component() to better reflect its purpose. Additionally, the test_set_component() function now sets the agent parameter using the set_component() method instead of raising a ValueError. This change improves the readability and maintainability of the code.

* refactor: Fix formatting issue in _build_error_string_from_matching_pairs

The _build_error_string_from_matching_pairs method in the Component class had a formatting issue when input types were empty. This commit fixes the issue by adding a check for empty input types and providing an empty list as a fallback. This improves the accuracy and readability of the error string generated by the method.

* fix(component.py): add validation to ensure output method is a string to prevent potential runtime errors

src/backend/tests/unit/custom/custom_component/test_component.py

@@ -18,11 +18,9 @@ def test_set_invalid_output():
         chatoutput.set(input_value=chatinput.build_config)
 
 
-def test_set_invalid_input():
+def test_set_component():
     crewai_agent = CrewAIAgentComponent()
     task = SequentialTaskComponent()
-    with pytest.raises(
-        ValueError,
-        match="You set CrewAI Agent as value for `agent`. You should pass one of the following: 'build_output'",
-    ):
-        task.set(agent=crewai_agent)
+    task.set(agent=crewai_agent)
+    assert task._edges[0]["source"] == crewai_agent._id
+    assert crewai_agent in task._components

src/backend/tests/unit/graph/graph/test_base.py

@@ -2,9 +2,11 @@ from collections import deque
 
 import pytest
 
+from langflow.components.agents.ToolCallingAgent import ToolCallingAgentComponent
 from langflow.components.inputs.ChatInput import ChatInput
 from langflow.components.outputs.ChatOutput import ChatOutput
 from langflow.components.outputs.TextOutput import TextOutputComponent
+from langflow.components.tools.YfinanceTool import YfinanceToolComponent
 from langflow.graph.graph.base import Graph
 from langflow.graph.graph.constants import Finish
 
@@ -139,3 +141,16 @@ def test_graph_functional_start_end():
     assert len(results) == len(ids) + 1
     assert all(result.vertex.id in ids for result in results if hasattr(result, "vertex"))
     assert results[-1] == Finish()
+
+
+def test_graph_set_with_invalid_component():
+    chat_input = ChatInput(_id="chat_input")
+    chat_output = ChatOutput(input_value="test", _id="chat_output")
+    with pytest.raises(ValueError, match="There are multiple outputs"):
+        chat_output.set(sender_name=chat_input)
+
+
+def test_graph_set_with_valid_component():
+    tool = YfinanceToolComponent()
+    tool_calling_agent = ToolCallingAgentComponent()
+    tool_calling_agent.set(tools=[tool])