1 files changed, 44 insertions, 0 deletions
diff --git a/node_modules/csso/lib/compressor/restructure/prepare/index.js b/node_modules/csso/lib/compressor/restructure/prepare/index.js
new file mode 100644
index 00000000..075dc5f1
--- /dev/null
+++ b/node_modules/csso/lib/compressor/restructure/prepare/index.js
@@ -0,0 +1,44 @@
+var resolveKeyword = require('../../../utils/names.js').keyword;
+var walkRules = require('../../../utils/walk.js').rules;
+var translate = require('../../../utils/translate.js');
+var createDeclarationIndexer = require('./createDeclarationIndexer.js');
+var processSelector = require('./processSelector.js');
+
+function walk(node, markDeclaration, usageData) {
+    switch (node.type) {
+        case 'Ruleset':
+            node.block.declarations.each(markDeclaration);
+            processSelector(node, usageData);
+            break;
+
+        case 'Atrule':
+            if (node.expression) {
+                node.expression.id = translate(node.expression);
+            }
+
+            // compare keyframe selectors by its values
+            // NOTE: still no clarification about problems with keyframes selector grouping (issue #197)
+            if (resolveKeyword(node.name).name === 'keyframes') {
+                node.block.avoidRulesMerge = true;  /* probably we don't need to prevent those merges for @keyframes
+                                                       TODO: need to be checked */
+                node.block.rules.each(function(ruleset) {
+                    ruleset.selector.selectors.each(function(simpleselector) {
+                        simpleselector.compareMarker = simpleselector.id;
+                    });
+                });
+            }
+            break;
+    }
+};
+
+module.exports = function prepare(ast, usageData) {
+    var markDeclaration = createDeclarationIndexer();
+
+    walkRules(ast, function(node) {
+        walk(node, markDeclaration, usageData);
+    });
+
+    return {
+        declaration: markDeclaration
+    };
+};