Fix all strong mode errors and warnings.

lib/src/tree.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of csslib.visitor;
 
 /////////////////////////////////////////////////////////////////////////
 // CSS specific types:
 /////////////////////////////////////////////////////////////////////////
 
@@ skipping 403 matching lines @@
   /** import name specified. */
   final String import;
 
   /** Any media queries for this import. */
   final List<MediaQuery> mediaQueries;
 
   ImportDirective(this.import, this.mediaQueries, SourceSpan span)
       : super(span);
 
   ImportDirective clone() {
-    var cloneMediaQueries = [];
+    var cloneMediaQueries = <MediaQuery>[];
     for (var mediaQuery in mediaQueries) {
       cloneMediaQueries.add(mediaQuery.clone());
     }
     return new ImportDirective(import, cloneMediaQueries, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitImportDirective(this);
 }
 
 /**
@@ skipping 41 matching lines @@
       : super(span);
 
   bool get hasMediaType => _mediaType != null;
   String get mediaType => _mediaType.name;
 
   bool get hasUnary => _mediaUnary != -1;
   String get unary =>
       TokenKind.idToValue(TokenKind.MEDIA_OPERATORS, _mediaUnary).toUpperCase();
 
   MediaQuery clone() {
-    var cloneExpressions = [];
+    var cloneExpressions = <MediaExpression>[];
     for (var expr in expressions) {
       cloneExpressions.add(expr.clone());
     }
     return new MediaQuery(_mediaUnary, _mediaType, cloneExpressions, span);
   }
   visit(VisitorBase visitor) => visitor.visitMediaQuery(this);
 }
 
 class MediaDirective extends Directive {
   final List<MediaQuery> mediaQueries;
   final List<RuleSet> rulesets;
 
   MediaDirective(this.mediaQueries, this.rulesets, SourceSpan span)
       : super(span);
 
   MediaDirective clone() {
-    var cloneQueries = [];
+    var cloneQueries = <MediaQuery>[];
     for (var mediaQuery in mediaQueries) {
       cloneQueries.add(mediaQuery.clone());
     }
-    var cloneRulesets = [];
+    var cloneRulesets = <RuleSet>[];
     for (var ruleset in rulesets) {
       cloneRulesets.add(ruleset.clone());
     }
     return new MediaDirective(cloneQueries, cloneRulesets, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitMediaDirective(this);
 }
 
 class HostDirective extends Directive {
   final List<RuleSet> rulesets;
 
   HostDirective(this.rulesets, SourceSpan span) : super(span);
 
   HostDirective clone() {
-    var cloneRulesets = [];
+    var cloneRulesets = <RuleSet>[];
     for (var ruleset in rulesets) {
       cloneRulesets.add(ruleset.clone());
     }
     return new HostDirective(cloneRulesets, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitHostDirective(this);
 }
 
 class PageDirective extends Directive {
   final String _ident;
   final String _pseudoPage;
   final List<DeclarationGroup> _declsMargin;
 
   PageDirective(
       this._ident, this._pseudoPage, this._declsMargin, SourceSpan span)
       : super(span);
 
   PageDirective clone() {
-    var cloneDeclsMargin = [];
+    var cloneDeclsMargin = <DeclarationGroup>[];
     for (var declMargin in _declsMargin) {
       cloneDeclsMargin.add(declMargin.clone());
     }
     return new PageDirective(_ident, _pseudoPage, cloneDeclsMargin, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitPageDirective(this);
 
   bool get hasIdent => _ident != null && _ident.length > 0;
   bool get hasPseudoPage => _pseudoPage != null && _pseudoPage.length > 0;
@@ skipping 74 matching lines @@
   final String dartClassName;
   final List<RuleSet> rulesets;
 
   StyletDirective(this.dartClassName, this.rulesets, SourceSpan span)
       : super(span);
 
   bool get isBuiltIn => false;
   bool get isExtension => true;
 
   StyletDirective clone() {
-    var cloneRulesets = [];
+    var cloneRulesets = <RuleSet>[];
     for (var ruleset in rulesets) {
       cloneRulesets.add(ruleset.clone());
     }
     return new StyletDirective(dartClassName, cloneRulesets, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitStyletDirective(this);
 }
 
 class NamespaceDirective extends Directive {
@@ skipping 19 matching lines @@
   VarDefinitionDirective(this.def, SourceSpan span) : super(span);
 
   VarDefinitionDirective clone() =>
       new VarDefinitionDirective(def.clone(), span);
 
   visit(VisitorBase visitor) => visitor.visitVarDefinitionDirective(this);
 }
 
 class MixinDefinition extends Directive {
   final String name;
-  final List definedArgs;
+  final List<TreeNode> definedArgs;
   final bool varArgs;
 
   MixinDefinition(this.name, this.definedArgs, this.varArgs, SourceSpan span)
       : super(span);
 
   MixinDefinition clone() {
-    var cloneDefinedArgs = [];
+    var cloneDefinedArgs = <TreeNode>[];
     for (var definedArg in definedArgs) {
       cloneDefinedArgs.add(definedArg.clone());
     }
     return new MixinDefinition(name, cloneDefinedArgs, varArgs, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitMixinDefinition(this);
 }
 
 /** Support a Sass @mixin. See http://sass-lang.com for description. */
 class MixinRulesetDirective extends MixinDefinition {
-  final List rulesets;
+  final List<TreeNode> rulesets;
 
-  MixinRulesetDirective(String name, List<VarDefinitionDirective> args,
+  MixinRulesetDirective(String name, List<VarDefinition> args,
       bool varArgs, this.rulesets, SourceSpan span)
       : super(name, args, varArgs, span);
 
   MixinRulesetDirective clone() {
-    var clonedArgs = [];
+    var clonedArgs = <VarDefinition>[];
     for (var arg in definedArgs) {
       clonedArgs.add(arg.clone());
     }
-    var clonedRulesets = [];
+    var clonedRulesets = <TreeNode>[];
     for (var ruleset in rulesets) {
       clonedRulesets.add(ruleset.clone());
     }
     return new MixinRulesetDirective(
         name, clonedArgs, varArgs, clonedRulesets, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitMixinRulesetDirective(this);
 }
 
 class MixinDeclarationDirective extends MixinDefinition {
   final DeclarationGroup declarations;
 
-  MixinDeclarationDirective(String name, List<VarDefinitionDirective> args,
+  MixinDeclarationDirective(String name, List<TreeNode> args,
       bool varArgs, this.declarations, SourceSpan span)
       : super(name, args, varArgs, span);
 
   MixinDeclarationDirective clone() {
-    var clonedArgs = [];
+    var clonedArgs = <TreeNode>[];
     for (var arg in definedArgs) {
       clonedArgs.add(arg.clone());
     }
     return new MixinDeclarationDirective(
         name, clonedArgs, varArgs, declarations.clone(), span);
   }
 
   visit(VisitorBase visitor) => visitor.visitMixinDeclarationDirective(this);
 }
 
 /** To support consuming a SASS mixin @include. */
 class IncludeDirective extends Directive {
   final String name;
-  final List<List<TreeNode>> args;
+  final List<List<Expression>> args;
 
   IncludeDirective(this.name, this.args, SourceSpan span) : super(span);
 
   IncludeDirective clone() {
-    var cloneArgs = [];
+    var cloneArgs = <List<Expression>>[];
     for (var arg in args) {
-      for (var term in arg) {
-        cloneArgs.add(term.clone());
-      }
+      cloneArgs.add(arg.map((term) => term.clone()).toList());

[Bob Nystrom, 2016/03/25 03:11:27]

I believe the previous code was wrong here.

     }
     return new IncludeDirective(name, cloneArgs, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitIncludeDirective(this);
 }
 
 /** To support SASS @content. */
 class ContentDirective extends Directive {
   ContentDirective(SourceSpan span) : super(span);
@@ skipping 84 matching lines @@
   ExtendDeclaration clone() {
     var newSelector = selectors.map((s) => s.clone()).toList();
     return new ExtendDeclaration(newSelector, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitExtendDeclaration(this);
 }
 
 class DeclarationGroup extends TreeNode {
   /** Can be either Declaration or RuleSet (if nested selector). */
-  final List declarations;
+  final List<TreeNode> declarations;
 
   DeclarationGroup(this.declarations, SourceSpan span) : super(span);
 
   DeclarationGroup clone() {
     var clonedDecls = declarations.map((d) => d.clone()).toList();
     return new DeclarationGroup(clonedDecls, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitDeclarationGroup(this);
 }
 
 class MarginGroup extends DeclarationGroup {
   final int margin_sym; // TokenType for for @margin sym.
 
-  MarginGroup(this.margin_sym, List<Declaration> decls, SourceSpan span)
+  MarginGroup(this.margin_sym, List<TreeNode> decls, SourceSpan span)
       : super(decls, span);
   MarginGroup clone() =>
-      new MarginGroup(margin_sym, super.clone() as dynamic, span);
+      new MarginGroup(margin_sym, super.clone().declarations, span);
   visit(VisitorBase visitor) => visitor.visitMarginGroup(this);
 }
 
 class VarUsage extends Expression {
   final String name;
   final List<Expression> defaultValues;
 
   VarUsage(this.name, this.defaultValues, SourceSpan span) : super(span);
 
   VarUsage clone() {
-    var clonedValues = [];
+    var clonedValues = <Expression>[];
     for (var expr in defaultValues) {
       clonedValues.add(expr.clone());
     }
     return new VarUsage(name, clonedValues, span);
   }
 
   visit(VisitorBase visitor) => visitor.visitVarUsage(this);
 }
 
 class OperatorSlash extends Expression {
@@ skipping 539 matching lines @@
 
   PaddingExpression._merge(
       PaddingExpression x, PaddingExpression y, SourceSpan span)
       : super(DartStyleExpression.paddingStyle, span,
           new BoxEdge.merge(x.box, y.box));
 
   PaddingExpression clone() => new PaddingExpression(span,
       top: box.top, right: box.right, bottom: box.bottom, left: box.left);
   visit(VisitorBase visitor) => visitor.visitPaddingExpression(this);
 }