test(object/mergeWith): add test cases for array merge with 'undefined' targetValue and skip overwrite when sourceValue is 'undefined' with 'merge' function returning 'undefined'

[sukvvon]

AS-IS

TO-BE

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Preview	Comments	Updated (UTC)
es-toolkit	Ready	Preview	Comment	Oct 9, 2025 5:48am

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.90%. Comparing base (21bd853) to head (02abeb4).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1447   +/-   ##
=======================================
  Coverage   99.90%   99.90%           
=======================================
  Files         468      468           
  Lines        4439     4439           
  Branches     1309     1309           
=======================================
  Hits         4435     4435           
  Misses          4        4           

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.