refactor: enhance tool creation logic and add FeatureFlags (#3662)

* Add `required_inputs` field to `Output` model in `base.py`

* Refactor ComponentTool to ComponentToolkit and enhance tool creation logic

- Replaced `ComponentTool` with `ComponentToolkit` to better encapsulate component-related tools.
- Introduced `build_description` and `_build_output_function` helper functions for dynamic tool creation.
- Updated tool initialization to handle multiple outputs and required inputs using `StructuredTool`.
- Improved schema creation for tool arguments based on component inputs.

* Refactor `to_tool` method to `to_toolkit` to use `ComponentToolkit` instead of `ComponentTool`

* Refactor `ComponentTool` to `ComponentToolkit` in unit tests

- Updated import statements to reflect the new `ComponentToolkit` class.
- Modified test logic to use `ComponentToolkit` for retrieving tools.
- Adjusted assertions to match the new structure and output format.
- Ensured compatibility with `Message` schema for output validation.

* Refactor `test_component_to_tool` to validate `ComponentToolkit` and tool properties

* Refactor `build_description` to include input types in the output format

* Add method to set required inputs for outputs based on method analysis

- Introduced `_set_output_required_inputs` method to determine and set required inputs for each output by analyzing the method's source code.
- Added necessary imports (`ast` and `dedent`) to support the new functionality.

* Update test to assert full tool description in test_component_to_tool.py

* Add unit tests for verifying required inputs of various components

- Added tests to ensure that required inputs for outputs are present in the inputs of `ChatInput`, `ChatOutput`, `SequentialTaskComponent`, `ToolCallingAgentComponent`, and `OpenAIModelComponent`.
- Included helper functions to check if required inputs are in inputs and to assert that all outputs have different required inputs.

* Add RequiredInputsVisitor to identify required inputs in AST nodes

- Introduced RequiredInputsVisitor class to traverse AST nodes and collect required inputs.
- The visitor checks for 'self' attributes matching the provided inputs and adds them to the required_inputs set.

* Refactor required inputs extraction using `RequiredInputsVisitor`

* Add feature flags configuration for toolkit output in settings

* Add toolkit output handling based on feature flag in custom component utils

* Add method to append 'component_as_tool' output in custom component

* Add unit test for toolkit output feature flag in custom component

* Add utility functions for lazy loading and instantiating input types in langflow

- Introduced `get_InputTypesMap` for lazy loading of `InputTypesMap`.
- Added `instantiate_input` function to create instances of input types dynamically.
- Included type checking and error handling for invalid input types.

* Refactor input instantiation logic and update imports

- Removed `instantiate_input` function from `inputs.py` and moved it to `utils.py`.
- Updated imports in `base.py` to reflect the new location of `instantiate_input`.
- Added missing import for `Callable` in `base.py`.

* Refactor import statement to use `instantiate_input` from `langflow.inputs.utils` in test_inputs.py

* Add TOOL_OUTPUT_NAME constant to tools module

* Add type checking and TOOL_OUTPUT_NAME filter in ComponentToolkit

- Introduced `TYPE_CHECKING` for type hints to avoid circular imports.
- Added `TOOL_OUTPUT_NAME` constant to filter specific outputs in `ComponentToolkit`.
- Updated type annotations to use forward references.

* Refactor component toolkit import to avoid circular dependency and use constant for tool output name

* Refactor `ComponentToolkit` class to remove inheritance from `BaseToolkit` and add an initializer for `component`

* Add unit test for ComponentToolkit in test_component_to_tool

- Added `test_component_to_tool_has_no_component_as_tool` to verify that `ComponentToolkit` correctly initializes with a `ChatInput` component and returns the expected tools.

* Refactor toolkit output handling to `custom_component` module

* fix: mypy errors union-attr and arg-type

* Add 'OTHER' field type to schema in langflow/io/schema.py

* Add tool name formatting to ComponentToolkit to ensure valid characters

* Refactor toolkit output handling and add type hint for `to_toolkit` method

* Add `is_interface_component` attribute to vertex types and update import order

* Add tests for ToolCallingAgentComponent and ChatOutput with API key handling

- Updated `test_component_tool` to reflect new description format.
- Added `test_component_tool_with_api_key` to test `ToolCallingAgentComponent` with `ChatOutput` and OpenAI API key.
- Enabled `add_toolkit_output` feature flag for testing.

* Refactor `_find_matching_output_method` to accept `input_name` parameter for more precise input-output matching

* Replace ValueError with warning in build_description function

* use chat_output component directly in set

* [autofix.ci] apply automated fixes

* [autofix.ci] apply automated fixes

* [autofix.ci] apply automated fixes (attempt 3/3)

* Refactor: Reorder method calls in `__init__` for logical consistency

Moved `set_class_code` method call to ensure output types and required inputs are set before class code initialization.

* Update _format_tool_name to allow '.' in tool names

* Refactor `_format_tool_name` to remove non-alphanumeric characters

* Update test assertions for component tool name and output mapping

* Handle case where 'required_inputs' is empty in 'component_tool.py'

* Refactor import statements for better readability in `base.py`

* [autofix.ci] apply automated fixes

* Add noqa comment to suppress import warning and re-add Any import in base.py

---------

Co-authored-by: italojohnny <italojohnnydosanjos@gmail.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

src/backend/tests/unit/test_custom_component.py

@@ -11,6 +11,7 @@ from langflow.custom.code_parser.code_parser import CodeParser, CodeSyntaxError
 from langflow.custom.custom_component.base_component import BaseComponent, ComponentCodeNullError
 from langflow.custom.utils import build_custom_component_template
 from langflow.services.database.models.flow import FlowCreate
+from langflow.services.settings.feature_flags import FEATURE_FLAGS
 
 
 @pytest.fixture
@@ -543,6 +544,14 @@ def test_custom_component_multiple_outputs(code_component_with_multiple_outputs,
     assert frontnd_node_dict["outputs"][0]["types"] == ["Text"]
 
 
+def test_feature_flags_add_toolkit_output(active_user, code_component_with_multiple_outputs):
+    frontnd_node_dict, _ = build_custom_component_template(code_component_with_multiple_outputs, active_user.id)
+    len_outputs = len(frontnd_node_dict["outputs"])
+    FEATURE_FLAGS.add_toolkit_output = True
+    frontnd_node_dict, _ = build_custom_component_template(code_component_with_multiple_outputs, active_user.id)
+    assert len(frontnd_node_dict["outputs"]) == len_outputs + 1
+
+
 def test_custom_component_subclass_from_lctoolcomponent():
     # Import LCToolComponent and create a subclass
     code = dedent("""