[Misc] Add tensor schema test coverage for multimodal models

[Isotr0py]

Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.

Purpose

• Since some large LMMs aren't run on CI due to memory limitation, we should make sure newly added tensor schema won't break anything.
• Add test to cover tensor schema validation for each multimodal model.

Test Plan

pytest -s -v tests/models/multimodal/test_tensor_schema.py

Test Result

• Test should pass without any error.

(Optional) Documentation Update

[github-actions]

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[gemini-code-assist]

Code Review

This pull request adds a new test to validate tensor schemas for multimodal models, which is a valuable addition for ensuring model input correctness. The overall approach is sound, but I've identified a few areas for improvement. The test currently only covers a single model architecture, uses internal APIs, and is specific to the V0 engine. My feedback focuses on expanding test coverage, improving maintainability by using public APIs, and, most importantly, updating the test to be compatible with the V1 engine to ensure its long-term value.

[Isotr0py]

Refer to https://buildkite.com/vllm/fastcheck/builds/33014#01985c44-e73a-4cb8-8fd4-68684f687912

  | [2025-07-30T19:34:16Z] FAILED models/multimodal/test_tensor_schema.py::test_model_tensor_schema[DeepseekVLV2ForCausalLM] - ValueError: data has rank 5 but expected 4
  | [2025-07-30T19:34:16Z] FAILED models/multimodal/test_tensor_schema.py::test_model_tensor_schema[H2OVLChatModel] - pydantic_core._pydantic_core.ValidationError: 1 validation error for ModelConfig
  | [2025-07-30T19:34:16Z]   Value error, The repository h2oai/h2ovl-mississippi-800m contains custom code which must be executed to correctly load the model. You can inspect the repository content at https://hf.co/h2oai/h2ovl-mississippi-800m .
  | [2025-07-30T19:34:16Z]  You can inspect the repository content at https://hf.co/h2oai/h2ovl-mississippi-800m.
  | [2025-07-30T19:34:16Z] Please pass the argument `trust_remote_code=True` to allow custom code to be run. [type=value_error, input_value=ArgsKwargs(('h2oai/h2ovl-...se, 'hf_overrides': {}}), input_type=ArgsKwargs]
  | [2025-07-30T19:34:16Z]     For further information visit https://errors.pydantic.dev/2.11/v/value_error
  | [2025-07-30T19:34:16Z] FAILED models/multimodal/test_tensor_schema.py::test_model_tensor_schema[KeyeForConditionalGeneration] - ValueError: pixel_values has rank 5 but expected 2
  | [2025-07-30T19:34:16Z] FAILED models/multimodal/test_tensor_schema.py::test_model_tensor_schema[MiniMaxVL01ForConditionalGeneration] - ValueError: The expected shape of pixel values is ('batch_size', '3', '336', '336'). You supplied (3, 19, 3, 336, 336).
  | [2025-07-30T19:34:16Z] = 4 failed, 131 passed, 31 skipped, 923 deselected, 104 warnings in 4275.53s (1:11:15) =

Broken models due to TensorSchema:

• DeepseekVLV2ForCausalLM
• KeyeForConditionalGeneration

Possible broken models unrelated to TensorSchema:

• MiniMaxVL01ForConditionalGeneration!?

[DarkLight1337]

@bbeckca please hold off on additional PRs until this is merged, otherwise you will have to merge these changes into many PRs.

[bbeckca]

Thanks @Isotr0py for improving model coverage and fixes! Please feel free to share any feedback to help make these changes safer in the future.

[DarkLight1337]

PTAL at the failing tests

[DarkLight1337]

Sorry I missed that models/multimodal/test_tensor_schema.py::test_model_tensor_schema[Glm4MoeForCausalLM] is failing, can you fix it?