move the property check out of the ruleset and fix an issue in the visitor

lib/less/to-css-visitor.js

@@ -17,6 +17,10 @@
             return ruleNode;
         },
 
+        visitMixinDefinition: function (mixinNode, visitArgs) {
+            return [];
+        },
+
         visitComment: function (commentNode, visitArgs) {
             if (commentNode.isSilent(this._env)) {
                 return [];
@@ -42,21 +46,56 @@
             return directiveNode;
         },
 
+        checkPropertiesInRoot: function(rules) {
+            var ruleNode;
+            for(var i = 0; i < rules.length; i++) {
+                ruleNode = rules[i];
+                if (ruleNode instanceof tree.Rule && !ruleNode.variable) {
+                    throw { message: "properties must be inside selector blocks, they cannot be in the root.",
+                        index: ruleNode.index, filename: ruleNode.currentFileInfo ? ruleNode.currentFileInfo.filename : null};
+                }
+            }
+        },
+
         visitRuleset: function (rulesetNode, visitArgs) {
             var rule, rulesets = [];
+            if (rulesetNode.firstRoot) {
+                this.checkPropertiesInRoot(rulesetNode.rules);
+            }
             if (! rulesetNode.root) {
+
+                rulesetNode.paths = rulesetNode.paths
+                    .filter(function(p) {
+                        var i;
+                        for(i = 0; i < p.length; i++) {
+                            if (p[i].getIsReferenced() && p[i].getIsOutput()) {
+                                return true;
+                            }
+                            return false;
+                        }
+                    });
+
                 // Compile rules and rulesets
                 for (var i = 0; i < rulesetNode.rules.length; i++) {
                     rule = rulesetNode.rules[i];
 
                     if (rule.rules) {
+                        // visit because we are moving them out from being a child
                         rulesets.push(this._visitor.visit(rule));
                         rulesetNode.rules.splice(i, 1);
                         i--;
                         continue;
                     }
                 }
-                if (rulesets.length > 0 && rulesetNode.rules.length > 0) {
+                // accept the visitor to remove rules and refactor itself
+                // then we can decide now whether we want it or not
+                if (rulesetNode.rules.length > 0 && rulesetNode.paths.length > 0) {
+                    rulesetNode.accept(this._visitor);
+                }
+                visitArgs.visitDeeper = false;
+
+                // now decide whether we keep the ruleset
+                if (rulesets.length > 0 && rulesetNode.rules.length > 0 && rulesetNode.paths.length > 0) {
                     rulesets.splice(0, 0, rulesetNode);
                 }
             }

lib/less/tree/ruleset.js

@@ -204,10 +204,6 @@ tree.Ruleset.prototype = {
                 }
             } else {
                 if (rule.toCSS) {
-                    if (this.firstRoot && rule instanceof tree.Rule) {
-                        throw { message: "properties must be inside selector blocks, they cannot be in the root.",
-                            index: rule.index, filename: rule.currentFileInfo ? rule.currentFileInfo.filename : null};
-                    }
                     rules.push(rule.toCSS(env));
                 } else if (rule.value) {
                     rules.push(rule.value.toString());
@@ -234,15 +230,6 @@ tree.Ruleset.prototype = {
             if (rules.length > 0) {
                 debugInfo = tree.debugInfo(env, this);
                 selector = this.paths
-                    .filter(function(p) {
-                        var i;
-                        for(i = 0; i < p.length; i++) {
-                            if (p[i].getIsReferenced() && p[i].getIsOutput()) {
-                                return true;
-                            }
-                            return false;
-                        }
-                    })
                     .map(function (p) {
                         return p.map(function (s) {
                             return s.toCSS(env);
@@ -270,6 +257,9 @@ tree.Ruleset.prototype = {
         return css.join('')  + (env.compress ? '\n' : '');
     },
 
+    toCSSRoot: function (env) {
+    },
+
     markReferenced: function () {
         for (var s = 0; s < this.selectors.length; s++) {
             this.selectors[s].markReferenced();

lib/less/visitor.js

@@ -40,7 +40,7 @@
                 var evald = this.visit(nodes[i]);
                 if (evald instanceof Array) {
                     evald = this.flatten(evald);
-                    evald.forEach(this.doAccept, this);
+                    //evald.forEach(this.doAccept, this);
                     newNodes = newNodes.concat(evald);
                 } else {
                     newNodes.push(evald);