Fixes signature help active parameter highlighting ,issue num 1417

[kshitijgetsac]

Summary

Fixes signature help active parameter highlighting issue where the wrong parameter was being highlighted during function call completion.

Problem

When typing inside a function parameter (e.g., np.array([1], dtype=), the signature help incorrectly highlighted the next parameter (copy) instead of the current one being typed (dtype).

Root Cause

The bug was caused by setting the active_parameter field at both:

1. The SignatureHelp level (correct - indicates which parameter globally)
2. The individual SignatureInformation level (incorrect - should be None)

According to the LSP specification, active_parameter should only be set at the SignatureHelp level to indicate which parameter is currently active across all signature overloads.

Changes Made

• Removed the active_parameter calculation from create_signature_information function in lsp.rs
• Removed unused arg_index parameter from create_signature_information
• Updated the call site in get_signature_help_at to not pass arg_index
• Updated test expectations in signature_help.rs to check active_parameter at the correct level

Testing

• Code compiles successfully
• All existing tests pass (including 6 updated signature help tests)
• Code follows the LSP specification for signature help

Fixes #1417

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[aaron-ang]

Hi @kshitijgetsac, I don't think your patch fixes the issue. I checked out your branch and built the LSP locally. It still fails with the example provided in the issue

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[kshitijgetsac]

@aaron-ang thanks for letting me know , appreciate the help.

[kshitijgetsac]

The issue was fixed by @aaron-ang and my implementation did not work