fix: make format parameter optional in os.date function

[tinyleolin]

No description provided.

[github-actions]

Code Review Summary

File: crates/emmylua_code_analysis/resources/std/os.lua

Change: Line 81 - @param format string → @param format? string

✅ Issue Identified: Incorrect Parameter Type Annotation

Problem: The original annotation @param format string incorrectly marks the format parameter as required, when in Lua's os.date() function it is actually optional.

Evidence:

• The Lua 5.1/5.2/5.3 reference manual states that os.date([format [, time]]) has both parameters as optional
• When called without arguments, os.date() returns the current date/time as a string using the default format
• The existing @overload annotations already demonstrate optional usage patterns

Recommendation: The change from @param format string to @param format? string is correct and should be approved. This fix:

• Aligns the type annotation with actual Lua language specification
• Matches the existing overload signatures that show optional usage
• Improves code analysis accuracy for downstream tools

Additional Observations

1. Consistency Check: The time parameter is already correctly annotated as @param time? number (optional), so this change makes the format parameter consistent.

2. No Other Issues Found: The change is minimal, focused, and addresses a clear documentation/annotation error without introducing any new problems.

Final Verdict

APPROVED - This is a straightforward, correct fix that improves the accuracy of the type annotations for Lua's os.date() function.

[gemini-code-assist]

Code Review

This pull request updates the Lua standard library definition for the os.date function in crates/emmylua_code_analysis/resources/std/os.lua, marking the format parameter as optional to accurately reflect its usage. No review comments were provided for this change, so I have no additional feedback to offer.