[BugFix] Accept hyphenated FunctionGemma tool names in non-streaming parse by cs-fisha · Pull Request #57989 · vllm-project/vllm

cs-fisha · 2026-09-21T17:49:09Z

Summary

Non-streaming FunctionGemmaToolParser.tool_call_regex used \w+ for the function name, so names like get-weather failed to match and the raw control frame was returned as content. Streaming already accepted hyphens via func_part.split("{")[0].

Widen the name group to [\w-]+ in both alternations so non-streaming matches streaming and OpenAI-legal hyphenated tool names.

Test plan

pytest tests/tool_parsers/test_functiongemma_tool_parser.py --noconftest (17 passed)
ruff check / ruff format --check on the touched files
Added non-streaming and streaming regression tests for get-weather

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Open (2)

If the intent is to match OpenAI-style tool name constraints, \\w in Python is Unicode-aware by… · New
This assertion is brittle because it depends on exact JSON formatting/whitespace and how arguments… · New

What changed in this PR

Fixes non-streaming FunctionGemmaToolParser parsing to accept hyphenated tool/function names (e.g., get-weather), aligning behavior with the streaming parser and preventing raw control frames from leaking into content.

Changes:

Widened the non-streaming tool-call regex name group from \w+ to [\w-]+ in both alternations.
Added regression tests for hyphenated tool names in both non-streaming and streaming extraction paths.

File	Description
vllm/tool_parsers/functiongemma_tool_parser.py	Updates tool-call regex to accept hyphenated tool names in non-streaming parsing.
tests/tool_parsers/test_functiongemma_tool_parser.py	Adds regression tests for hyphenated tool names in non-streaming and streaming modes.

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+        r"<start_function_call>call:([\w-]+)\{(.*?)\}<end_function_call>"
+        r"|<start_function_call>call:([\w-]+)\{(.*)",


+        assert name == "get-weather"
+        assert "".join(args_parts) == '{"city": "Paris"}'


github-actions · 2026-09-21T18:29:49Z

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cs-fisha · 2026-09-24T17:04:08Z

Addressed Copilot feedback on the streaming test: compare reconstructed tool arguments with json.loads instead of exact string equality. Left the [\w-]+ name class unchanged so non-streaming stays aligned with the streaming path (func_part.split("{")[0]), which already accepts hyphenated names like get-weather.

cs-fisha · 2026-10-05T05:04:54Z

pre-run-check is waiting on the ready label. Could a reviewer with write access add ready, or comment /ci run? I will keep this branch up to date.

smiyamoto3

The name fix looks right, and test_hyphenated_tool_name fails without it.

One question about arg_regex: it has the same \w+, and it silently cuts hyphenated keys in both modes:

<start_function_call>call:search{city:<escape>Paris<escape>,max-results:<escape>5<escape>}<end_function_call>
-> {"city": "Paris", "results": 5}

Would you fold [\w-]+ in there too, or should that be a separate PR?

nit: you kept [\w-]+ to match streaming, but names like get.weather still differ. Streaming emits the call, while non-streaming returns the raw text as content.

cs-fisha · 2026-10-28T20:04:51Z

Folded [\w-]+ into arg_regex on this branch. \w+ can match after the hyphen, so max-results was parsed as results in both modes. Non-streaming extract_tool_calls, _parse_arguments, and the streaming argument scan now keep the full key. Head is 616953b6d6.

I left the function-name class as [\w-]+. That matches OpenAI tool names. Streaming still takes the raw text before {, so a name like get.weather is emitted there and stays content in non-streaming. I did not widen the name class to . here.

mergify · 2026-11-02T12:21:55Z

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @cs-fisha.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

…parse Non-streaming tool_call_regex used \w+ and dropped names like get-weather, while streaming already accepted hyphens via split. Widen the name group to [\w-]+ and add regression coverage for both paths. Fixes vllm-project#57950 Signed-off-by: sinksilk <785976238@qq.com>

Avoid brittle exact-string equality on streamed argument chunks. Signed-off-by: sinksilk <785976238@qq.com>

Main replaced arg_regex with a scanner that already keeps hyphenated keys such as max-results. Add regression coverage for non-streaming and streaming so those keys cannot regress. Signed-off-by: sinksilk <785976238@qq.com> Co-authored-by: Si Chen <cs-fisha@users.noreply.github.com>

smiyamoto3

LGTM.

cs-fisha · 2026-11-03T08:38:01Z

/ci run

github-actions · 2026-11-03T08:38:21Z

❌ @cs-fisha, A reviewer with write access must run /ci run, approve the PR, or add the ready label first.

cs-fisha · 2026-11-03T09:51:55Z

Hi @bbrowning @chaunceyjiang @aarnphm @sfeng33 — this PR already has an approval from @smiyamoto3, but I don't have write access so /ci run was rejected. Could someone with write access please add the ready label or run /ci run? Thanks!

Copilot AI lite review requested due to automatic review settings September 21, 2026 17:49

cs-fisha requested review from aarnphm, bbrowning, chaunceyjiang and sfeng33 as code owners September 21, 2026 17:49

claude Bot reviewed Sep 21, 2026

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mergify Bot added tool-calling bug Something isn't working labels Sep 21, 2026

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cs-fisha force-pushed the fix-functiongemma-hyphenated-tool-names-57950 branch from 2c6bc44 to d2b80dd Compare September 21, 2026 18:04

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cs-fisha force-pushed the fix-functiongemma-hyphenated-tool-names-57950 branch 2 times, most recently from be5a9a6 to 97fd1fd Compare September 24, 2026 17:04

cs-fisha force-pushed the fix-functiongemma-hyphenated-tool-names-57950 branch from 97fd1fd to 3e85fd5 Compare October 1, 2026 08:36

stanleys12 mentioned this pull request Oct 2, 2026

[Bugfix][Tool Parser] Emit FunctionGemma tool calls that arrive in a single streaming delta #59754

Open

arpera moved this to Unsorted queue in Tool Calling (arpera) Oct 15, 2026

arpera added this to Tool Calling (arpera) Oct 15, 2026

arpera removed this from Tool Calling (arpera) Oct 15, 2026

arpera moved this to Unsorted issues in Tool Calling (arpera) Oct 15, 2026

arpera added this to Tool Calling (arpera) Oct 15, 2026

smiyamoto3 reviewed Oct 17, 2026

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arpera moved this from Unsorted PRs to not interested in Tool Calling (arpera) Oct 19, 2026

arpera removed this from Tool Calling Oct 21, 2026

This was referenced Oct 27, 2026

[Bug]: FunctionGemma converts escape-delimited string literals into numbers, booleans and null #63906

Open

[Bugfix] Preserve FunctionGemma escape-delimited string arguments #63947

Open

tdakhran mentioned this pull request Oct 30, 2026

[Bugfix][Tool Parser] LFM2: constrain forced tool_choice to the native format and parse hyphenated tool names #64750

Open

6 tasks done

mergify Bot added the needs-rebase label Nov 2, 2026

github-project-automation Bot added this to Tool Calling Nov 2, 2026

github-project-automation Bot moved this to Unsorted queue in Tool Calling Nov 2, 2026

cs-fisha and others added 3 commits November 2, 2026 13:35

[BugFix] Compare FunctionGemma streaming args via json.loads

114898d

Avoid brittle exact-string equality on streamed argument chunks. Signed-off-by: sinksilk <785976238@qq.com>

cursor Bot force-pushed the fix-functiongemma-hyphenated-tool-names-57950 branch from 616953b to e6a1620 Compare November 2, 2026 13:35

mergify Bot removed the needs-rebase label Nov 2, 2026

smiyamoto3 approved these changes Nov 2, 2026

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Merge branch 'main' into fix-functiongemma-hyphenated-tool-names-57950

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[BugFix] Accept hyphenated FunctionGemma tool names in non-streaming parse - #57989

[BugFix] Accept hyphenated FunctionGemma tool names in non-streaming parse#57989
cs-fisha wants to merge 4 commits into
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cs-fisha:fix-functiongemma-hyphenated-tool-names-57950

cs-fisha commented Sep 21, 2026 •

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		r"<start_function_call>call:([\w-]+)\{(.*?)\}<end_function_call>"
		r"\|<start_function_call>call:([\w-]+)\{(.*)",

		assert name == "get-weather"
		assert "".join(args_parts) == '{"city": "Paris"}'

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