fix(theme): Fix code block magic comments with CRLF line breaks bug

[coder-xiaomo]

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Motivation

fix: with CRLF line breaks, an extra empty line was rendered with // highlight-end at end of code blocks

Test Plan

Related issues/PRs

See: #11036

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[slorber]

LGTM thanks

Can you add a unit test for it in docusaurus/packages/docusaurus-theme-common/src/utils/__tests__/codeBlockUtils.test.ts?

(if you don't know how, tell me and I can do it for you)

[coder-xiaomo]

@slorber Okay, I've written the following test case with reference to other test cases. However, this issue requires both code block highlighting comment // highlight-end and CRLF to be satisfied simultaneously. I'm not sure if this test case can accurately describe this situation:

// add to `describe('parseLines')` part

it('handles CRLF line breaks with highlight comments correctly', () => {
    const defaultMagicComments: MagicCommentConfig[] = [
        {
            className: 'theme-code-block-highlighted-line',
            line: 'highlight-next-line',
            block: { start: 'highlight-start', end: 'highlight-end' }
        }
    ];

    expect(
        parseLines(`// highlight-start aaaaa\r\nbbbbb\r\n// highlight-end`, {
            metastring: '',
            language: 'js',
            magicComments: defaultMagicComments
        })
    ).toMatchSnapshot();
});

[slorber]

Yes it should be fine.

I've added the tests needed based on your proposal above, also adding one for the highlight metastring range {2} syntax which was impacted by your change through a different code path.

Good to merge thanks 👍