shift73k/assets_old/node_modules/csso/lib/clean/Atrule.js

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var resolveKeyword = require('css-tree').keyword;
var { hasNoChildren } = require('./utils');
module.exports = function cleanAtrule(node, item, list) {
if (node.block) {
// otherwise removed at-rule don't prevent @import for removal
if (this.stylesheet !== null) {
this.stylesheet.firstAtrulesAllowed = false;
}
if (hasNoChildren(node.block)) {
list.remove(item);
return;
}
}
switch (node.name) {
case 'charset':
if (hasNoChildren(node.prelude)) {
list.remove(item);
return;
}
// if there is any rule before @charset -> remove it
if (item.prev) {
list.remove(item);
return;
}
break;
case 'import':
if (this.stylesheet === null || !this.stylesheet.firstAtrulesAllowed) {
list.remove(item);
return;
}
// if there are some rules that not an @import or @charset before @import
// remove it
list.prevUntil(item.prev, function(rule) {
if (rule.type === 'Atrule') {
if (rule.name === 'import' || rule.name === 'charset') {
return;
}
}
this.root.firstAtrulesAllowed = false;
list.remove(item);
return true;
}, this);
break;
default:
var name = resolveKeyword(node.name).basename;
if (name === 'keyframes' ||
name === 'media' ||
name === 'supports') {
// drop at-rule with no prelude
if (hasNoChildren(node.prelude) || hasNoChildren(node.block)) {
list.remove(item);
}
}
}
};