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; } } };