fix no-duplicate-selectors

[vankop]

Which issue, if any, is this issue related to?

Fixes #4113

Is there anything in the PR that needs further explanation?

current test cases can not find this problem, to reproduce in current master branch commit ->1178f2d2d4c7d83d12ad4ec55b686a7bf7e28995 add:
expect(output.results[0].warnings).toHaveLength(1);
here https://github.com/stylelint/stylelint/blob/master/jest-setup.js#L92

run node node_modules/jest/bin/jest.js lib/rules/no-duplicate-selectors/__tests__/index.js

[hudochenkov]

Please, don't force push if someone left review to your PR. This way we could see what have changed since last review.

Don't worry about clean Git history. We always use “squash and merge” so all commit gets squashed into one on PR merge.

[hudochenkov]

One more thing. Since you're member of stylelint team you can now use main repository to work on your PRs. This way it's simpler for you, because you don't need to keep your fork updated :)

[vankop]

One more thing. Since you're member of stylelint team you can now use main repository to work on your PRs. This way it's simpler for you, because you don't need to keep your fork updated :)

But then I need to delete branches to keep repo clean =)

Please, don't force push if someone left review to your PR. This way we could see what have changed since last review.

I have forgotten about it sorry =(

[hudochenkov]

But then I need to delete branches to keep repo clean =)

After merge new button “Delete branch” appears in the PR :)

[hudochenkov]

Good job!

[vankop]

@hudochenkov Did not found out why tests failed

[alexander-akait]

Maybe conditional race on windows, we need search place who do this 😕

[hudochenkov]

I happens sometimes for unknown reason.

[hudochenkov]

• Fixed: no-duplicate-selectors false positives for selectors in the same selector list (#4173).