UNPKG

@cowprotocol/cow-sdk

Version:

<p align="center"> <img width="400" src="https://github.com/cowprotocol/cow-sdk/raw/main/docs/images/CoW.png" /> </p>

58 lines (39 loc) 2.11 kB
# Selector Specificity [<img alt="npm version" src="https://img.shields.io/npm/v/@csstools/selector-specificity.svg" height="20">][npm-url] [<img alt="Build Status" src="https://github.com/csstools/postcss-plugins/workflows/test/badge.svg" height="20">][cli-url] [<img alt="Discord" src="https://shields.io/badge/Discord-5865F2?logo=discord&logoColor=white">][discord] ## Usage Add [Selector Specificity] to your project: ```bash npm install postcss @csstools/selector-specificity --save-dev ``` ```js import parser from 'postcss-selector-parser'; import { selectorSpecificity } from '@csstools/selector-specificity'; const selectorAST = parser().astSync('#foo:has(> .foo)'); const specificity = selectorSpecificity(selectorAST); console.log(specificity.a); // 1 console.log(specificity.b); // 1 console.log(specificity.c); // 0 ``` _`selectorSpecificity` takes a single selector, not a list of selectors (not : `a, b, c`). To compare or otherwise manipulate lists of selectors you need to call `selectorSpecificity` on each part._ ### Comparing The package exports a utility function to compare two specificities. ```js import { selectorSpecificity, compare } from '@csstools/selector-specificity'; const s1 = selectorSpecificity(ast1); const s2 = selectorSpecificity(ast2); compare(s1, s2); // -1 | 0 | 1 ``` - if `s1 < s2` then `compare(s1, s2)` returns a negative number (`< 0`) - if `s1 > s2` then `compare(s1, s2)` returns a positive number (`> 0`) - if `s1 === s2` then `compare(s1, s2)` returns zero (`=== 0`) ## Prior Art - [keeganstreet/specificity](https://github.com/keeganstreet/specificity) - [bramus/specificity](https://github.com/bramus/specificity) For CSSTools we always use `postcss-selector-parser` and want to calculate specificity from this AST. [cli-url]: https://github.com/csstools/postcss-plugins/actions/workflows/test.yml?query=workflow/test [discord]: https://discord.gg/bUadyRwkJS [npm-url]: https://www.npmjs.com/package/@csstools/selector-specificity [Selector Specificity]: https://github.com/csstools/postcss-plugins/tree/main/packages/selector-specificity