raise exception for pin_lora

[andyxning]

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

raise exception instead of return an exception.

Test Plan

NA

Test Result

NA

(Optional) Documentation Update

[github-actions]

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[gemini-code-assist]

Summary of Changes

Hello @andyxning, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request primarily focuses on improving error handling consistency within the vllm worker base by changing a method to explicitly raise an exception instead of returning an exception object. Additionally, a minor stylistic cleanup was performed in another method to enhance code readability.

Highlights

• Error Handling Consistency: The pin_lora method in vllm/worker/worker_base.py was updated to raise ValueError directly when LoRA is not supported. This change aligns its behavior with other similar methods like remove_lora and list_loras, ensuring that an actual exception is propagated rather than an exception object being returned as a value.
• Code Style Improvement: Redundant parentheses were removed from an if condition within the execute_model method in vllm/worker/worker_base.py for improved readability and adherence to common Python style guidelines.

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[gemini-code-assist]

Code Review

This pull request correctly addresses a bug in the pin_lora method within the LoRANotSupportedWorkerBase class. By changing return ValueError(...) to raise ValueError(...), it ensures that an exception is properly raised to indicate that LoRA operations are not supported by this worker type, rather than incorrectly returning an exception object.

To improve the PR, please consider filling out the PR description checklist (Purpose, Test Plan, Test Result). This provides valuable context for reviewers and helps with future maintenance, even for small changes.

[gemini-code-assist]

This change correctly replaces return ValueError(...) with raise ValueError(...).

Previously, returning an exception object (ValueError(...)) would not interrupt the program flow as an exception. Instead, the caller would receive a ValueError instance, which is not the intended behavior for signaling an error condition. Raising the exception ensures that the error is properly propagated and can be handled by appropriate try...except blocks or will terminate the operation as expected.

This is a crucial correctness fix.

The -> bool return type annotation in the method signature is part of the interface defined by WorkerBase and implemented by other derived classes (e.g., Worker) that do support LoRA and return a boolean. For this LoRANotSupportedWorkerBase class, which explicitly does not support LoRA, raising an exception is the appropriate way to signal this. The # type: ignore comment is correctly kept to silence type checker warnings (like those from a strict mypy configuration) about this specific implementation not actually returning a bool due to the raise statement.