52 lines
1.6 KiB
JavaScript
52 lines
1.6 KiB
JavaScript
'use strict';
|
|
|
|
const cssTree = require('css-tree');
|
|
const utils = require('./utils.cjs');
|
|
|
|
function processRule(node, item, list) {
|
|
const selectors = node.prelude.children;
|
|
const declarations = node.block.children;
|
|
|
|
list.prevUntil(item.prev, function(prev) {
|
|
// skip non-ruleset node if safe
|
|
if (prev.type !== 'Rule') {
|
|
return utils.unsafeToSkipNode.call(selectors, prev);
|
|
}
|
|
|
|
const prevSelectors = prev.prelude.children;
|
|
const prevDeclarations = prev.block.children;
|
|
|
|
// try to join rulesets with equal pseudo signature
|
|
if (node.pseudoSignature === prev.pseudoSignature) {
|
|
// try to join by selectors
|
|
if (utils.isEqualSelectors(prevSelectors, selectors)) {
|
|
prevDeclarations.appendList(declarations);
|
|
list.remove(item);
|
|
return true;
|
|
}
|
|
|
|
// try to join by declarations
|
|
if (utils.isEqualDeclarations(declarations, prevDeclarations)) {
|
|
utils.addSelectors(prevSelectors, selectors);
|
|
list.remove(item);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// go to prev ruleset if has no selector similarities
|
|
return utils.hasSimilarSelectors(selectors, prevSelectors);
|
|
});
|
|
}
|
|
|
|
// NOTE: direction should be left to right, since rulesets merge to left
|
|
// ruleset. When direction right to left unmerged rulesets may prevent lookup
|
|
// TODO: remove initial merge
|
|
function initialMergeRule(ast) {
|
|
cssTree.walk(ast, {
|
|
visit: 'Rule',
|
|
enter: processRule
|
|
});
|
|
}
|
|
|
|
module.exports = initialMergeRule;
|