Fixing import by reference

- refactored how import reference works
- refactored to-css-visitor (this is side product, it was getting
  complicated)
- fixes issues less#1851, less#1896, less#1878, less#2716, less#1968, less#2162 (same as less#1896)

lib/less/contexts.js

@@ -30,7 +30,6 @@ var parseCopyProperties = [
     // context
     'processImports',   // option & context - whether to process imports. if false then imports will not be imported.
                         // Used by the import manager to stop multiple import visitors being created.
-    'reference',        // Used to indicate that the contents are imported by reference
     'pluginManager'     // Used as the plugin manager for the session
 ];
 

lib/less/parser/parser.js

@@ -35,7 +35,7 @@ var LessError = require('../less-error'),
 //    Token matching is done with the `$` function, which either takes
 //    a terminal string or regexp, or a non-terminal function to call.
 //    It also takes care of moving all the indices forwards.
-//
+//`
 //
 var Parser = function Parser(context, imports, fileInfo) {
     var parsers,
@@ -603,7 +603,7 @@ var Parser = function Parser(context, imports, fileInfo) {
                     if (!elements) {
                         error("Missing target selector for :extend().");
                     }
-                    extend = new(tree.Extend)(new(tree.Selector)(elements), option, index);
+                    extend = new(tree.Extend)(new(tree.Selector)(elements), option, index, fileInfo);
                     if (extendList) {
                         extendList.push(extend);
                     } else {
@@ -1474,7 +1474,6 @@ var Parser = function Parser(context, imports, fileInfo) {
                     parserInput.forget();
                     return new (tree.Directive)(name, value, rules, index, fileInfo,
                         context.dumpLineNumbers ? getDebugInfo(index) : null,
-                        false,
                         isRooted
                     );
                 }

lib/less/transform-tree.js

@@ -39,6 +39,7 @@ module.exports = function(root, options) {
     var preEvalVisitors = [],
         visitors = [
             new visitor.JoinSelectorVisitor(),
+            new visitor.MarkVisibleSelectorsVisitor(true),
             new visitor.ExtendVisitor(),
             new visitor.ToCSSVisitor({compress: Boolean(options.compress)})
         ], i;

lib/less/tree/anonymous.js

@@ -1,17 +1,18 @@
 var Node = require("./node");
 
-var Anonymous = function (value, index, currentFileInfo, mapLines, rulesetLike, referenced) {
+var Anonymous = function (value, index, currentFileInfo, mapLines, rulesetLike, visibilityInfo) {
     this.value = value;
     this.index = index;
     this.mapLines = mapLines;
     this.currentFileInfo = currentFileInfo;
     this.rulesetLike = (typeof rulesetLike === 'undefined') ? false : rulesetLike;
-    this.isReferenced = referenced || false;
+
+    this.copyVisibilityInfo(visibilityInfo);
 };
 Anonymous.prototype = new Node();
 Anonymous.prototype.type = "Anonymous";
 Anonymous.prototype.eval = function () {
-    return new Anonymous(this.value, this.index, this.currentFileInfo, this.mapLines, this.rulesetLike, this.isReferenced);
+    return new Anonymous(this.value, this.index, this.currentFileInfo, this.mapLines, this.rulesetLike, this.visibilityInfo());
 };
 Anonymous.prototype.compare = function (other) {
     return other.toCSS && this.toCSS() === other.toCSS() ? 0 : undefined;
@@ -22,11 +23,4 @@ Anonymous.prototype.isRulesetLike = function() {
 Anonymous.prototype.genCSS = function (context, output) {
     output.add(this.value, this.currentFileInfo, this.index, this.mapLines);
 };
-Anonymous.prototype.markReferenced = function () {
-    this.isReferenced = true;
-};
-Anonymous.prototype.getIsReferenced = function () {
-    return !this.currentFileInfo || !this.currentFileInfo.reference || this.isReferenced;
-};
-
 module.exports = Anonymous;

lib/less/tree/comment.js

@@ -15,11 +15,7 @@ Comment.prototype.genCSS = function (context, output) {
     output.add(this.value);
 };
 Comment.prototype.isSilent = function(context) {
-    var isReference = (this.currentFileInfo && this.currentFileInfo.reference && !this.isReferenced),
-        isCompressed = context.compress && this.value[2] !== "!";
-    return this.isLineComment || isReference || isCompressed;
-};
-Comment.prototype.markReferenced = function () {
-    this.isReferenced = true;
+    var isCompressed = context.compress && this.value[2] !== "!";
+    return this.isLineComment || isCompressed;
 };
 module.exports = Comment;

lib/less/tree/directive.js

@@ -2,7 +2,7 @@ var Node = require("./node"),
     Selector = require("./selector"),
     Ruleset = require("./ruleset");
 
-var Directive = function (name, value, rules, index, currentFileInfo, debugInfo, isReferenced, isRooted) {
+var Directive = function (name, value, rules, index, currentFileInfo, debugInfo, isRooted, visibilityInfo) {
     var i;
 
     this.name  = name;
@@ -21,8 +21,8 @@ var Directive = function (name, value, rules, index, currentFileInfo, debugInfo,
     this.index = index;
     this.currentFileInfo = currentFileInfo;
     this.debugInfo = debugInfo;
-    this.isReferenced = isReferenced;
     this.isRooted = isRooted || false;
+    this.copyVisibilityInfo(visibilityInfo);
 };
 
 Directive.prototype = new Node();
@@ -79,7 +79,7 @@ Directive.prototype.eval = function (context) {
     context.mediaBlocks = mediaBlocksBackup;
 
     return new Directive(this.name, value, rules,
-        this.index, this.currentFileInfo, this.debugInfo, this.isReferenced, this.isRooted);
+        this.index, this.currentFileInfo, this.debugInfo, this.isRooted, this.visibilityInfo());
 };
 Directive.prototype.variable = function (name) {
     if (this.rules) {
@@ -99,21 +99,6 @@ Directive.prototype.rulesets = function () {
         return Ruleset.prototype.rulesets.apply(this.rules[0]);
     }
 };
-Directive.prototype.markReferenced = function () {
-    var i, rules;
-    this.isReferenced = true;
-    if (this.rules) {
-        rules = this.rules;
-        for (i = 0; i < rules.length; i++) {
-            if (rules[i].markReferenced) {
-                rules[i].markReferenced();
-            }
-        }
-    }
-};
-Directive.prototype.getIsReferenced = function () {
-    return !this.currentFileInfo || !this.currentFileInfo.reference || this.isReferenced;
-};
 Directive.prototype.outputRuleset = function (context, output, rules) {
     var ruleCnt = rules.length, i;
     context.tabLevel = (context.tabLevel | 0) + 1;

lib/less/tree/element.js

@@ -2,7 +2,7 @@ var Node = require("./node"),
     Paren = require("./paren"),
     Combinator = require("./combinator");
 
-var Element = function (combinator, value, index, currentFileInfo) {
+var Element = function (combinator, value, index, currentFileInfo, info) {
     this.combinator = combinator instanceof Combinator ?
                       combinator : new Combinator(combinator);
 
@@ -15,6 +15,7 @@ var Element = function (combinator, value, index, currentFileInfo) {
     }
     this.index = index;
     this.currentFileInfo = currentFileInfo;
+    this.copyVisibilityInfo(info);
 };
 Element.prototype = new Node();
 Element.prototype.type = "Element";
@@ -29,7 +30,13 @@ Element.prototype.eval = function (context) {
     return new Element(this.combinator,
                              this.value.eval ? this.value.eval(context) : this.value,
                              this.index,
-                             this.currentFileInfo);
+                             this.currentFileInfo, this.visibilityInfo());
+};
+Element.prototype.clone = function () {
+    return new Element(this.combinator,
+        this.value,
+        this.index,
+        this.currentFileInfo, this.visibilityInfo());
 };
 Element.prototype.genCSS = function (context, output) {
     output.add(this.toCSS(context), this.currentFileInfo, this.index);

lib/less/tree/expression.js

@@ -53,9 +53,4 @@ Expression.prototype.throwAwayComments = function () {
         return !(v instanceof Comment);
     });
 };
-Expression.prototype.markReferenced = function () {
-    this.value.forEach(function (value) {
-        if (value.markReferenced) { value.markReferenced(); }
-    });
-};
 module.exports = Expression;

lib/less/tree/extend.js

@@ -1,11 +1,14 @@
-var Node = require("./node");
+var Node = require("./node"),
+    Selector = require("./selector");
 
-var Extend = function Extend(selector, option, index) {
+var Extend = function Extend(selector, option, index, currentFileInfo, visibilityInfo) {
     this.selector = selector;
     this.option = option;
     this.index = index;
     this.object_id = Extend.next_id++;
     this.parent_ids = [this.object_id];
+    this.currentFileInfo = currentFileInfo || {};
+    this.copyVisibilityInfo(visibilityInfo);
 
     switch(option) {
         case "all":
@@ -26,11 +29,12 @@ Extend.prototype.accept = function (visitor) {
     this.selector = visitor.visit(this.selector);
 };
 Extend.prototype.eval = function (context) {
-    return new Extend(this.selector.eval(context), this.option, this.index);
+    return new Extend(this.selector.eval(context), this.option, this.index, this.currentFileInfo, this.visibilityInfo());
 };
 Extend.prototype.clone = function (context) {
-    return new Extend(this.selector, this.option, this.index);
+    return new Extend(this.selector, this.option, this.index, this.currentFileInfo, this.visibilityInfo());
 };
+//it concatenates (joins) all selectors in selector array
 Extend.prototype.findSelfSelectors = function (selectors) {
     var selfElements = [],
         i,
@@ -46,6 +50,7 @@ Extend.prototype.findSelfSelectors = function (selectors) {
         selfElements = selfElements.concat(selectors[i].elements);
     }
 
-    this.selfSelectors = [{ elements: selfElements }];
+    this.selfSelectors = [new Selector(selfElements)];
+    this.selfSelectors[0].copyVisibilityInfo(this.visibilityInfo());
 };
 module.exports = Extend;

lib/less/tree/import.js

@@ -17,7 +17,7 @@ var Node = require("./node"),
 // `import,push`, we also pass it a callback, which it'll call once
 // the file has been fetched, and parsed.
 //
-var Import = function (path, features, options, index, currentFileInfo) {
+var Import = function (path, features, options, index, currentFileInfo, visibilityInfo) {
     this.options = options;
     this.index = index;
     this.path = path;
@@ -32,6 +32,7 @@ var Import = function (path, features, options, index, currentFileInfo) {
             this.css = true;
         }
     }
+    this.copyVisibilityInfo(visibilityInfo);
 };
 
 //
@@ -87,7 +88,7 @@ Import.prototype.evalForImport = function (context) {
         path = path.value;
     }
 
-    return new Import(path.eval(context), this.features, this.options, this.index, this.currentFileInfo);
+    return new Import(path.eval(context), this.features, this.options, this.index, this.currentFileInfo, this.visibilityInfo());
 };
 Import.prototype.evalPath = function (context) {
     var path = this.path.eval(context);
@@ -107,6 +108,20 @@ Import.prototype.evalPath = function (context) {
     return path;
 };
 Import.prototype.eval = function (context) {
+    var result = this.doEval(context);
+    if (this.options.reference || this.blocksVisibility()) {
+        if (result.length || result.length === 0) {
+            result.forEach(function (node) {
+                    node.addVisibilityBlock();
+                }
+            );
+        } else {
+            result.addVisibilityBlock();
+        }
+    }
+    return result;
+};
+Import.prototype.doEval = function (context) {
     var ruleset, registry,
         features = this.features && this.features.eval(context);
 
@@ -126,13 +141,12 @@ Import.prototype.eval = function (context) {
             return [];
         }
     }
-
     if (this.options.inline) {
         var contents = new Anonymous(this.root, 0,
           {
               filename: this.importedFilename,
               reference: this.path.currentFileInfo && this.path.currentFileInfo.reference
-          }, true, true, false);
+          }, true, true);
 
         return this.features ? new Media([contents], this.features.value) : [contents];
     } else if (this.css) {
@@ -143,7 +157,6 @@ Import.prototype.eval = function (context) {
         return newImport;
     } else {
         ruleset = new Ruleset(null, this.root.rules.slice(0));
-
         ruleset.evalImports(context);
 
         return this.features ? new Media(ruleset.rules, this.features.value) : ruleset.rules;

lib/less/tree/media.js

@@ -5,7 +5,7 @@ var Ruleset = require("./ruleset"),
     Expression = require("./expression"),
     Directive = require("./directive");
 
-var Media = function (value, features, index, currentFileInfo) {
+var Media = function (value, features, index, currentFileInfo, visibilityInfo) {
     this.index = index;
     this.currentFileInfo = currentFileInfo;
 
@@ -14,6 +14,7 @@ var Media = function (value, features, index, currentFileInfo) {
     this.features = new Value(features);
     this.rules = [new Ruleset(selectors, value)];
     this.rules[0].allowImports = true;
+    this.copyVisibilityInfo(visibilityInfo);
 };
 Media.prototype = new Directive();
 Media.prototype.type = "Media";
@@ -37,7 +38,7 @@ Media.prototype.eval = function (context) {
         context.mediaPath = [];
     }
 
-    var media = new Media(null, [], this.index, this.currentFileInfo);
+    var media = new Media(null, [], this.index, this.currentFileInfo, this.visibilityInfo());
     if (this.debugInfo) {
         this.rules[0].debugInfo = this.debugInfo;
         media.debugInfo = this.debugInfo;
@@ -77,6 +78,7 @@ Media.prototype.evalTop = function (context) {
         var selectors = (new Selector([], null, null, this.index, this.currentFileInfo)).createEmptySelectors();
         result = new Ruleset(selectors, context.mediaBlocks);
         result.multiMedia = true;
+        result.copyVisibilityInfo(this.visibilityInfo());
     }
 
     delete context.mediaBlocks;

lib/less/tree/mixin-call.js

@@ -22,7 +22,7 @@ MixinCall.prototype.accept = function (visitor) {
 };
 MixinCall.prototype.eval = function (context) {
     var mixins, mixin, mixinPath, args = [], arg, argValue,
-        rules = [], rule, match = false, i, m, f, isRecursive, isOneFound,
+        rules = [], match = false, i, m, f, isRecursive, isOneFound,
         candidates = [], candidate, conditionResult = [], defaultResult, defFalseEitherCase = -1,
         defNone = 0, defTrue = 1, defFalse = 2, count, originalRuleset, noArgumentsFilter;
 
@@ -127,26 +127,19 @@ MixinCall.prototype.eval = function (context) {
                         mixin = candidates[m].mixin;
                         if (!(mixin instanceof MixinDefinition)) {
                             originalRuleset = mixin.originalRuleset || mixin;
-                            mixin = new MixinDefinition("", [], mixin.rules, null, false);
+                            mixin = new MixinDefinition("", [], mixin.rules, null, false, null, originalRuleset.visibilityInfo());
                             mixin.originalRuleset = originalRuleset;
                         }
-                        Array.prototype.push.apply(
-                            rules, mixin.evalCall(context, args, this.important).rules);
+                        var newRules = mixin.evalCall(context, args, this.important).rules;
+                        this._setVisibilityToReplacement(newRules);
+                        Array.prototype.push.apply(rules, newRules);
                     } catch (e) {
                         throw { message: e.message, index: this.index, filename: this.currentFileInfo.filename, stack: e.stack };
                     }
                 }
             }
 
             if (match) {
-                if (!this.currentFileInfo || !this.currentFileInfo.reference) {
-                    for (i = 0; i < rules.length; i++) {
-                        rule = rules[i];
-                        if (rule.markReferenced) {
-                            rule.markReferenced();
-                        }
-                    }
-                }
                 return rules;
             }
         }
@@ -161,6 +154,16 @@ MixinCall.prototype.eval = function (context) {
             index:   this.index, filename: this.currentFileInfo.filename };
     }
 };
+
+MixinCall.prototype._setVisibilityToReplacement = function (replacement) {
+    var i, rule;
+    if (this.blocksVisibility()) {
+        for (i = 0; i < replacement.length; i++) {
+            rule = replacement[i];
+            rule.addVisibilityBlock();
+        }
+    }
+};
 MixinCall.prototype.format = function (args) {
     return this.selector.toCSS().trim() + '(' +
         (args ? args.map(function (a) {