var generate = require('css-tree').generate; var specificity = require('./specificity'); var nonFreezePseudoElements = { 'first-letter': true, 'first-line': true, 'after': true, 'before': true }; var nonFreezePseudoClasses = { 'link': true, 'visited': true, 'hover': true, 'active': true, 'first-letter': true, 'first-line': true, 'after': true, 'before': true }; module.exports = function freeze(node, usageData) { var pseudos = Object.create(null); var hasPseudo = false; node.prelude.children.each(function(simpleSelector) { var tagName = '*'; var scope = 0; simpleSelector.children.each(function(node) { switch (node.type) { case 'ClassSelector': if (usageData && usageData.scopes) { var classScope = usageData.scopes[node.name] || 0; if (scope !== 0 && classScope !== scope) { throw new Error('Selector can\'t has classes from different scopes: ' + generate(simpleSelector)); } scope = classScope; } break; case 'PseudoClassSelector': var name = node.name.toLowerCase(); if (!nonFreezePseudoClasses.hasOwnProperty(name)) { pseudos[':' + name] = true; hasPseudo = true; } break; case 'PseudoElementSelector': var name = node.name.toLowerCase(); if (!nonFreezePseudoElements.hasOwnProperty(name)) { pseudos['::' + name] = true; hasPseudo = true; } break; case 'TypeSelector': tagName = node.name.toLowerCase(); break; case 'AttributeSelector': if (node.flags) { pseudos['[' + node.flags.toLowerCase() + ']'] = true; hasPseudo = true; } break; case 'WhiteSpace': case 'Combinator': tagName = '*'; break; } }); simpleSelector.compareMarker = specificity(simpleSelector).toString(); simpleSelector.id = null; // pre-init property to avoid multiple hidden class simpleSelector.id = generate(simpleSelector); if (scope) { simpleSelector.compareMarker += ':' + scope; } if (tagName !== '*') { simpleSelector.compareMarker += ',' + tagName; } }); // add property to all rule nodes to avoid multiple hidden class node.pseudoSignature = hasPseudo && Object.keys(pseudos).sort().join(','); };