classes() function does not resolve Tailwind class conflicts when element has existing classes

[mamadshni]

Please provide the environment you discovered this bug in.

Node: v24.6.0
Angular: v20.0.6

Which area/package is the issue in?

accordion

Description

@spartan-ng/helm/utils

Other information

Expected behavior: When calling classes(() => ['bg-red-500', 'text-white']) on an element with existing class bg-blue-500 p-2, the result should be p-2 text-white bg-red-500 (new bg-* replaces old).

The existing test in the codebase documents this bug - the comment says one thing but the expectation tests for the opposite:

it('should handle class merging and deduplication', async () => {
  ....
  // twMerge should resolve bg conflict, keeping the last one (bg-red-500)
  expect(element.className).toBe('text-white bg-blue-500 p-2'); // ← keeps bg-blue-500, not bg-red-500
  ....
}

I would be willing to submit a PR to fix this issue

• Yes
• No

[marcjulian]

@ashley-hunter could you take a look at this one?

[ashley-hunter]

Hi, I believe this is working as expected. If a component defines bg-red-500 as its style, but a user has explicitly defined bg-blue-500 on it, bg-blue-500 should take precedence.

[mamadshni]

I understand the point you're talking about, in this case then in my opinion the tests should be updated, since the test description and result of it are not inline