first commit

app_vue/node_modules/csso/lib/restructure/8-restructRuleset.js

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+var List = require('css-tree').List;
+var walk = require('css-tree').walk;
+var utils = require('./utils');
+
+function calcSelectorLength(list) {
+    var length = 0;
+
+    list.each(function(data) {
+        length += data.id.length + 1;
+    });
+
+    return length - 1;
+}
+
+function calcDeclarationsLength(tokens) {
+    var length = 0;
+
+    for (var i = 0; i < tokens.length; i++) {
+        length += tokens[i].length;
+    }
+
+    return (
+        length +          // declarations
+        tokens.length - 1 // delimeters
+    );
+}
+
+function processRule(node, item, list) {
+    var avoidRulesMerge = this.block !== null ? this.block.avoidRulesMerge : false;
+    var selectors = node.prelude.children;
+    var block = node.block;
+    var disallowDownMarkers = Object.create(null);
+    var allowMergeUp = true;
+    var allowMergeDown = true;
+
+    list.prevUntil(item.prev, function(prev, prevItem) {
+        var prevBlock = prev.block;
+        var prevType = prev.type;
+
+        if (prevType !== 'Rule') {
+            var unsafe = utils.unsafeToSkipNode.call(selectors, prev);
+
+            if (!unsafe && prevType === 'Atrule' && prevBlock) {
+                walk(prevBlock, {
+                    visit: 'Rule',
+                    enter: function(node) {
+                        node.prelude.children.each(function(data) {
+                            disallowDownMarkers[data.compareMarker] = true;
+                        });
+                    }
+                });
+            }
+
+            return unsafe;
+        }
+
+        var prevSelectors = prev.prelude.children;
+
+        if (node.pseudoSignature !== prev.pseudoSignature) {
+            return true;
+        }
+
+        allowMergeDown = !prevSelectors.some(function(selector) {
+            return selector.compareMarker in disallowDownMarkers;
+        });
+
+        // try prev ruleset if simpleselectors has no equal specifity and element selector
+        if (!allowMergeDown && !allowMergeUp) {
+            return true;
+        }
+
+        // try to join by selectors
+        if (allowMergeUp && utils.isEqualSelectors(prevSelectors, selectors)) {
+            prevBlock.children.appendList(block.children);
+            list.remove(item);
+            return true;
+        }
+
+        // try to join by properties
+        var diff = utils.compareDeclarations(block.children, prevBlock.children);
+
+        // console.log(diff.eq, diff.ne1, diff.ne2);
+
+        if (diff.eq.length) {
+            if (!diff.ne1.length && !diff.ne2.length) {
+                // equal blocks
+                if (allowMergeDown) {
+                    utils.addSelectors(selectors, prevSelectors);
+                    list.remove(prevItem);
+                }
+
+                return true;
+            } else if (!avoidRulesMerge) { /* probably we don't need to prevent those merges for @keyframes
+                                              TODO: need to be checked */
+
+                if (diff.ne1.length && !diff.ne2.length) {
+                    // prevBlock is subset block
+                    var selectorLength = calcSelectorLength(selectors);
+                    var blockLength = calcDeclarationsLength(diff.eq); // declarations length
+
+                    if (allowMergeUp && selectorLength < blockLength) {
+                        utils.addSelectors(prevSelectors, selectors);
+                        block.children = new List().fromArray(diff.ne1);
+                    }
+                } else if (!diff.ne1.length && diff.ne2.length) {
+                    // node is subset of prevBlock
+                    var selectorLength = calcSelectorLength(prevSelectors);
+                    var blockLength = calcDeclarationsLength(diff.eq); // declarations length
+
+                    if (allowMergeDown && selectorLength < blockLength) {
+                        utils.addSelectors(selectors, prevSelectors);
+                        prevBlock.children = new List().fromArray(diff.ne2);
+                    }
+                } else {
+                    // diff.ne1.length && diff.ne2.length
+                    // extract equal block
+                    var newSelector = {
+                        type: 'SelectorList',
+                        loc: null,
+                        children: utils.addSelectors(prevSelectors.copy(), selectors)
+                    };
+                    var newBlockLength = calcSelectorLength(newSelector.children) + 2; // selectors length + curly braces length
+                    var blockLength = calcDeclarationsLength(diff.eq); // declarations length
+
+                    // create new ruleset if declarations length greater than
+                    // ruleset description overhead
+                    if (blockLength >= newBlockLength) {
+                        var newItem = list.createItem({
+                            type: 'Rule',
+                            loc: null,
+                            prelude: newSelector,
+                            block: {
+                                type: 'Block',
+                                loc: null,
+                                children: new List().fromArray(diff.eq)
+                            },
+                            pseudoSignature: node.pseudoSignature
+                        });
+
+                        block.children = new List().fromArray(diff.ne1);
+                        prevBlock.children = new List().fromArray(diff.ne2overrided);
+
+                        if (allowMergeUp) {
+                            list.insert(newItem, prevItem);
+                        } else {
+                            list.insert(newItem, item);
+                        }
+
+                        return true;
+                    }
+                }
+            }
+        }
+
+        if (allowMergeUp) {
+            // TODO: disallow up merge only if any property interception only (i.e. diff.ne2overrided.length > 0);
+            // await property families to find property interception correctly
+            allowMergeUp = !prevSelectors.some(function(prevSelector) {
+                return selectors.some(function(selector) {
+                    return selector.compareMarker === prevSelector.compareMarker;
+                });
+            });
+        }
+
+        prevSelectors.each(function(data) {
+            disallowDownMarkers[data.compareMarker] = true;
+        });
+    });
+}
+
+module.exports = function restructRule(ast) {
+    walk(ast, {
+        visit: 'Rule',
+        reverse: true,
+        enter: processRule
+    });
+};