tailwindcss/src/jit/lib/resolveDefaultsAtRules.js
2021-07-01 05:18:37 -04:00

69 lines
1.6 KiB
JavaScript

import postcss from 'postcss'
import selectorParser from 'postcss-selector-parser'
let elementSelectorParser = selectorParser((selectors) => {
return selectors.map((s) => {
return s
.split((n) => n.type === 'combinator')
.pop()
.filter((n) => n.type !== 'pseudo' || n.value.startsWith('::'))
.join('')
.trim()
})
})
let cache = new Map()
function extractElementSelector(selector) {
if (!cache.has(selector)) {
cache.set(selector, elementSelectorParser.transformSync(selector))
}
return cache.get(selector)
}
export default function resolveDefaultsAtRules() {
return (root) => {
let variableNodeMap = new Map()
let universals = new Set()
root.walkAtRules('defaults', (rule) => {
if (rule.nodes.length > 0) {
universals.add(rule)
return
}
let variable = rule.params
if (!variableNodeMap.has(variable)) {
variableNodeMap.set(variable, new Set())
}
variableNodeMap.get(variable).add(rule.parent)
rule.remove()
})
for (let universal of universals) {
let selectors = new Set()
let rules = variableNodeMap.get(universal.params) ?? []
for (let rule of rules) {
for (let selector of extractElementSelector(rule.selector)) {
selectors.add(selector)
}
}
if (selectors.size === 0) {
universal.remove()
continue
}
let universalRule = postcss.rule()
universalRule.selectors = [...selectors]
universalRule.append(universal.nodes)
universal.before(universalRule)
universal.remove()
}
}
}