cssnano/cssnano

Can't discard duplicate rules

Open

#86 opened on Nov 2, 2015

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 (4 comments) (2 reactions) (0 assignees)CSS (4,909 stars) (324 forks)batch import
enhancementhelp wanted

Description

code: body { padding: 50px; }

body { padding: 0; }

results: body{padding:50px;padding:0}

What can I do to get the results as: body {padding:0}

Contributor guide

Tech stack
javascript
Domain
frontendbuild system
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
PostCSS plugin developmentCSS minification concepts
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
The issue requests that duplicate CSS rules be discarded during minification. Check existing cssnano plugins (e.g., related to merging or discarding) to see if similar functionality exists or how to implement a new one. Review the PostCSS plugin API and look at the parsed AST structure for rules. The implementation would likely involve traversing the CSS AST and removing duplicate rule blocks.