epiphany/node_modules/csso/lib/clean/Rule.js
2023-12-09 22:48:07 -08:00

100 lines
4 KiB
JavaScript

import { walk, keyword } from 'css-tree';
import { hasNoChildren } from './utils.js';
const { hasOwnProperty } = Object.prototype;
const skipUsageFilteringAtrule = new Set(['keyframes']);
function cleanUnused(selectorList, usageData) {
selectorList.children.forEach((selector, item, list) => {
let shouldRemove = false;
walk(selector, function(node) {
// ignore nodes in nested selectors
if (this.selector === null || this.selector === selectorList) {
switch (node.type) {
case 'SelectorList':
// TODO: remove toLowerCase when pseudo selectors will be normalized
// ignore selectors inside :not()
if (this.function === null || this.function.name.toLowerCase() !== 'not') {
if (cleanUnused(node, usageData)) {
shouldRemove = true;
}
}
break;
case 'ClassSelector':
if (usageData.whitelist !== null &&
usageData.whitelist.classes !== null &&
!hasOwnProperty.call(usageData.whitelist.classes, node.name)) {
shouldRemove = true;
}
if (usageData.blacklist !== null &&
usageData.blacklist.classes !== null &&
hasOwnProperty.call(usageData.blacklist.classes, node.name)) {
shouldRemove = true;
}
break;
case 'IdSelector':
if (usageData.whitelist !== null &&
usageData.whitelist.ids !== null &&
!hasOwnProperty.call(usageData.whitelist.ids, node.name)) {
shouldRemove = true;
}
if (usageData.blacklist !== null &&
usageData.blacklist.ids !== null &&
hasOwnProperty.call(usageData.blacklist.ids, node.name)) {
shouldRemove = true;
}
break;
case 'TypeSelector':
// TODO: remove toLowerCase when type selectors will be normalized
// ignore universal selectors
if (node.name.charAt(node.name.length - 1) !== '*') {
if (usageData.whitelist !== null &&
usageData.whitelist.tags !== null &&
!hasOwnProperty.call(usageData.whitelist.tags, node.name.toLowerCase())) {
shouldRemove = true;
}
if (usageData.blacklist !== null &&
usageData.blacklist.tags !== null &&
hasOwnProperty.call(usageData.blacklist.tags, node.name.toLowerCase())) {
shouldRemove = true;
}
}
break;
}
}
});
if (shouldRemove) {
list.remove(item);
}
});
return selectorList.children.isEmpty;
}
export default function cleanRule(node, item, list, options) {
if (hasNoChildren(node.prelude) || hasNoChildren(node.block)) {
list.remove(item);
return;
}
// avoid usage filtering for some at-rules
if (this.atrule && skipUsageFilteringAtrule.has(keyword(this.atrule.name).basename)) {
return;
}
const { usage } = options;
if (usage && (usage.whitelist !== null || usage.blacklist !== null)) {
cleanUnused(node.prelude, usage);
if (hasNoChildren(node.prelude)) {
list.remove(item);
return;
}
}
};