feat: (and fix) Add enable_streaming_passthrough to ToolInvoker and add missing params to to_dict

[sjrl]

Related Issues

• fixes #issue-number

Proposed Changes:

Add enable_streaming_passthrough at the request of the platform team (@tstadel). This is to allow the ToolInvoker to pass the streaming_callback to the tool invocation if the tool supports it. This only occurs if this flag is set to True and if the tool has a streaming_callback parameter in its invoke method signature. This is to more easily enable Tools that contain Components or SuperComponents that support streaming (e.g. Agent) and allow them to stream in a deployment setting. @tstadel has more details on the complexity on this.

Fixed the to_dict and from_dict methods of ToolInvoker to properly serliaze it's init parameters. For example, streaming_callback serialization was missing.

How did you test it?

• Added unit tests

Notes for the reviewer

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test: and added ! in case the PR includes breaking changes.
• I documented my code
• I ran pre-commit hooks and fixed any issue

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Pull Request Test Coverage Report for Build 15486550666

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Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 66 unchanged lines in 7 files lost coverage.
• Overall coverage increased (+0.07%) to 90.463%

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Files with Coverage Reduction	New Missed Lines	%
dataclasses/init.py	1	46.15%
utils/hf.py	2	85.29%
dataclasses/streaming_chunk.py	5	90.38%
components/generators/chat/openai.py	7	95.76%
components/generators/chat/hugging_face_api.py	8	95.63%
components/generators/utils.py	9	76.0%
components/tools/tool_invoker.py	34	83.94%

Totals
Change from base Build 15468967841:	0.07%
Covered Lines:	11535
Relevant Lines:	12751

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💛 - Coveralls

[tstadel]

@sjrl thanks a lot for this. Nice & clean, looking great!
Just a bit more context on the issue:

• we must pass the streaming callback as run param to components when running the pipeline behind a concurrently working api (so each stream is bound to the right request)
• passing the streaming callback directly to a component that is part of a tool(pipeline) is not possible as the run invocation is fully controlled/owned by ToolInvoker

Looking forward to having this!

[sjrl]

@mpangrazzi just realized I should add a specific test for this since I'm unsure if inspect.signature will work well in the case for ComponentTool since it's defined as def component_invoker(**kwargs) and I don't think we update the signature of the component_invoker using the available input_sockets = component.__haystack_input__._sockets_dict .

So for this to work as expected for ComponentTool specifically it may be better to check if the tool_schema has streaming_callback present rather than relying on inspect.signature

[mpangrazzi]

Looks good! I've added two comments, one might be relevant.

[sjrl]

@mpangrazzi just realized I should add a specific test for this since I'm unsure if inspect.signature will work well in the case for ComponentTool since it's defined as def component_invoker(**kwargs) and I don't think we update the signature of the component_invoker using the available input_sockets = component.__haystack_input__._sockets_dict .

So for this to work as expected for ComponentTool specifically it may be better to check if the tool_schema has streaming_callback present rather than relying on inspect.signature

Added a test and a fix for this. New utility method called _get_func_params which reuses existing code for tackling this exact issue with ComponentTool

[mpangrazzi]

LGTM!