parcel-bundler / parcel-bundler/lightningcss

Nesting misses selector minification opportunity

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#464 2 comments 0 reactions 0 assignees View on GitHub

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area: minification
Dominant language
Rust
Stars
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Forks
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Description

With CSS nesting

a {
    cursor:pointer;
    + b {
        cursor:pointer;
    }
}

compiles to

a{cursor:pointer}a+b{cursor:pointer}

Without CSS nesting

a {
    cursor:pointer;
}
a + b {
    cursor:pointer;
}

compiles to

a,a+b{cursor:pointer}

Contributor guide

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First steps

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  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start from the CSS nesting and selector minification paths, using the issue's nested and non-nested examples as the expected comparison. Add a regression case for equivalent selectors and verify that the nested form is combined when safe; run the relevant minifier test suite to confirm the optimized output.

Written by the indexing model from the issue text.

Assessment

Tech stack
css, rust
Domain
tooling
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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