Strenghtened scope protection for detached rulesets. #186

src/main/java/com/github/sommeri/less4j/core/compiler/expressions/ExpressionFilter.java

@@ -5,5 +5,7 @@
 public interface ExpressionFilter {
 
   Expression apply(Expression input);
+
+  boolean accepts(String name, Expression value);
 
 }

src/main/java/com/github/sommeri/less4j/core/compiler/expressions/ExpressionsEvaluator.java

@@ -117,6 +117,11 @@ private ExpressionFilter toEvaluationFilter() {
       public Expression apply(Expression input) {
         return evaluate(input);
       }
+
+      @Override
+      public boolean accepts(String name, Expression value) {
+        return true;
+      }
     };
   }
 

src/main/java/com/github/sommeri/less4j/core/compiler/scopes/local/KeyValueStorage.java

@@ -50,6 +50,15 @@ public T getValue(M key) {
     return null;
   }
 
+  public void remove(M key) {
+    Iterator<Level<M, T>> di = levels.descendingIterator();
+    while (di.hasNext()) {
+      Level<M, T> level = di.next();
+      if (level.contains(key))
+        level.remove(key);
+    }
+  }
+
   public Set<Entry<M, T>> getAllEntries() {
     Set<Entry<M, T>> result = new HashSet<Entry<M,T>>();
     Iterator<Level<M, T>> iterator = levels.descendingIterator();
@@ -151,6 +160,10 @@ public T getValue(M key) {
       return storage.get(key);
     }
 
+    public void remove(M key) {
+      storage.remove(key);
+    }
+
     public boolean contains(M key) {
       return storage.containsKey(key);
     }

src/main/java/com/github/sommeri/less4j/core/compiler/scopes/local/VariablesDeclarationsStorage.java

@@ -19,6 +19,10 @@ public Expression getValue(String name) {
     return coolStorage.getValue(name);
   }
 
+  public void remove(String name) {
+    coolStorage.remove(name);
+  }
+
   public void store(AbstractVariableDeclaration node) {
     store(node.getVariable().getName(), node.getValue());
   }
@@ -48,7 +52,8 @@ public void addFilteredVariables(ExpressionFilter filter, VariablesDeclarationsS
     for (Entry<String, Expression> entry : variablesSource.coolStorage.getAllEntries()) {
       String name = entry.getKey();
       Expression value = entry.getValue();
-      store(name, filter.apply(value));
+      if (filter.accepts(name, value))
+        store(name, filter.apply(value));
     }
   }
 

src/main/java/com/github/sommeri/less4j/core/compiler/stages/MixinsSolver.java → src/main/java/com/github/sommeri/less4j/core/compiler/stages/MixinsRulesetsSolver.java

@@ -26,7 +26,7 @@
 import com.github.sommeri.less4j.core.compiler.scopes.ScopeFactory;
 import com.github.sommeri.less4j.core.problems.ProblemsHandler;
 
-class MixinsSolver {
+class MixinsRulesetsSolver {
 
   private final ProblemsHandler problemsHandler;
   private final ReferencesSolver parentSolver;
@@ -35,15 +35,15 @@ class MixinsSolver {
   private final DefaultGuardHelper defaultGuardHelper;
   private final CallerCalleeScopeJoiner scopeManipulation = new CallerCalleeScopeJoiner();
 
-  public MixinsSolver(ReferencesSolver parentSolver, AstNodesStack semiCompiledNodes, ProblemsHandler problemsHandler, Configuration configuration) {
+  public MixinsRulesetsSolver(ReferencesSolver parentSolver, AstNodesStack semiCompiledNodes, ProblemsHandler problemsHandler, Configuration configuration) {
     this.parentSolver = parentSolver;
     this.semiCompiledNodes = semiCompiledNodes;
     this.problemsHandler = problemsHandler;
     this.configuration = configuration;
     this.defaultGuardHelper = new DefaultGuardHelper(problemsHandler);
   }
 
-  private BodyCompilationResult resolveCalledBody(final IScope callerScope, final BodyOwner<?> bodyOwner, final IScope bodyWorkingScope) {
+  private BodyCompilationResult resolveCalledBody(final IScope callerScope, final BodyOwner<?> bodyOwner, final IScope bodyWorkingScope, final ScopeProtection protectionLevel) {
     final ExpressionsEvaluator expressionEvaluator = new ExpressionsEvaluator(bodyWorkingScope, problemsHandler, configuration);
 
     final IScope referencedMixinScope = bodyWorkingScope;
@@ -57,7 +57,7 @@ public BodyCompilationResult run() {
 
         // collect variables and mixins to be imported
         IScope returnValues = ScopeFactory.createDummyScope();
-        returnValues.addFilteredVariables(new ImportedScopeFilter(expressionEvaluator, callerScope), referencedMixinScope);
+        returnValues.addFilteredVariables(new ImportedScopeFilter(expressionEvaluator, callerScope, protectionLevel), referencedMixinScope);
         List<FullMixinDefinition> unmodifiedMixinsToImport = referencedMixinScope.getAllMixins();
 
         List<FullMixinDefinition> allMixinsToImport = scopeManipulation.mixinsToImport(callerScope, referencedMixinScope, unmodifiedMixinsToImport);
@@ -121,7 +121,7 @@ public void run() {
           if (guardValue != GuardValue.DO_NOT_USE) {
             //OPTIMIZATION POSSIBLE: there is no need to compile mixins at this point, some of them are not going to be 
             //used and create snapshot operation is cheap now. It should be done later on.
-            BodyCompilationResult compiled = resolveCalledBody(callerScope, fullMixin.getMixin(), mixinWorkingScope);
+            BodyCompilationResult compiled = resolveCalledBody(callerScope, fullMixin.getMixin(), mixinWorkingScope, ScopeProtection.LOCAL_ONLY);
             //mark the mixin according to its default() function use 
             compiled.setGuardValue(guardValue);
             //store the mixin as candidate
@@ -149,7 +149,7 @@ public void run() {
 
   public GeneralBody buildDetachedRulesetReplacement(DetachedRulesetReference reference, IScope callerScope, DetachedRuleset detachedRuleset, IScope detachedRulesetScope) {
     IScope mixinWorkingScope = scopeManipulation.joinIfIndependent(callerScope, detachedRulesetScope);
-    BodyCompilationResult compiled = resolveCalledBody(callerScope, detachedRuleset, mixinWorkingScope);
+    BodyCompilationResult compiled = resolveCalledBody(callerScope, detachedRuleset, mixinWorkingScope, ScopeProtection.FULL);
     GeneralBody result = new GeneralBody(reference.getUnderlyingStructure());
 
     result.addMembers(compiled.getReplacement());
@@ -186,11 +186,13 @@ class ImportedScopeFilter implements ExpressionFilter {
     private final ExpressionsEvaluator expressionEvaluator;
     private final IScope importTargetScope;
     private final CallerCalleeScopeJoiner scopeManipulation = new CallerCalleeScopeJoiner();
+    private final ScopeProtection protectionLevel;
 
-    public ImportedScopeFilter(ExpressionsEvaluator expressionEvaluator, IScope importTargetScope) {
+    public ImportedScopeFilter(ExpressionsEvaluator expressionEvaluator, IScope importTargetScope, ScopeProtection protectionLevel) {
       super();
       this.expressionEvaluator = expressionEvaluator;
       this.importTargetScope = importTargetScope;
+      this.protectionLevel = protectionLevel;
     }
 
     public Expression apply(Expression input) {
@@ -207,6 +209,14 @@ private IScope apply(IScope input) {
       return scopeManipulation.joinIfIndependentAndPreserveContent(importTargetScope, input);
     }
 
+    @Override
+    public boolean accepts(String name, Expression value) {
+      if (protectionLevel==ScopeProtection.LOCAL_ONLY)
+        return true;
+
+      return importTargetScope.getValue(name)==null;
+    }
+
   }
 
 }

src/main/java/com/github/sommeri/less4j/core/compiler/stages/ReferencesSolver.java

@@ -42,7 +42,7 @@ public class ReferencesSolver {
 
   public static final String ALL_ARGUMENTS = "@arguments";
   private ASTManipulator manipulator = new ASTManipulator();
-  private final MixinsSolver mixinsSolver;
+  private final MixinsRulesetsSolver mixinsSolver;
   private final ProblemsHandler problemsHandler;
   private final Configuration configuration;
   private final AstNodesStack semiCompiledNodes = new AstNodesStack();
@@ -52,7 +52,7 @@ public ReferencesSolver(ProblemsHandler problemsHandler, Configuration configura
     this.problemsHandler = problemsHandler;
     this.configuration = configuration;
     this.stringInterpolator = new StringInterpolator(problemsHandler);
-    this.mixinsSolver = new MixinsSolver(this, semiCompiledNodes, problemsHandler, configuration);
+    this.mixinsSolver = new MixinsRulesetsSolver(this, semiCompiledNodes, problemsHandler, configuration);
   }
 
   public void solveReferences(final ASTCssNode node, final IScope scope) {

src/main/java/com/github/sommeri/less4j/core/compiler/stages/ScopeProtection.java

@@ -0,0 +1,5 @@
+package com.github.sommeri.less4j.core.compiler.stages;
+
+public enum ScopeProtection {
+   LOCAL_ONLY, FULL
+}

src/test/resources/compile-basic-features/detached-rulesets/detached-rulesets-lessjs.css

@@ -2,7 +2,7 @@
   color: black;
   one: 1px;
   four: magic-frame;
-  visible-one: hidden and if you see this in the output its a bug;
+  visible-one: visible;
   visible-two: visible;
 }
 .wrap-selector {