Move expression logic from RecursiveStatementVisitor to RecursiveAstV…

…isitor

lib/src/visitor/recursive_ast.dart

@@ -2,6 +2,9 @@
 // MIT-style license that can be found in the LICENSE file or at
 // https://opensource.org/licenses/MIT.
 
+import 'package:meta/meta.dart';
+
+import '../util/nullable.dart';
 import '../ast/sass.dart';
 import 'interface/expression.dart';
 import 'recursive_statement.dart';
@@ -10,13 +13,134 @@ import 'recursive_statement.dart';
 /// AST.
 ///
 /// This extends [RecursiveStatementVisitor] to traverse each expression in
-/// addition to each statement.
+/// addition to each statement. It adds even more protected methods:
+///
+/// * [visitArgumentInvocation]
+/// * [visitSupportsCondition]
+/// * [visitInterpolation]
 ///
 /// {@category Visitor}
 abstract class RecursiveAstVisitor extends RecursiveStatementVisitor
     implements ExpressionVisitor<void> {
   const RecursiveAstVisitor();
 
+  void visitAtRootRule(AtRootRule node) {
+    super.visitAtRootRule(node);
+  }
+
+  void visitAtRule(AtRule node) {
+    visitInterpolation(node.name);
+    node.value.andThen(visitInterpolation);
+    super.visitAtRule(node);
+  }
+
+  void visitContentRule(ContentRule node) {
+    visitArgumentInvocation(node.arguments);
+  }
+
+  void visitDebugRule(DebugRule node) {
+    visitExpression(node.expression);
+  }
+
+  void visitDeclaration(Declaration node) {
+    visitInterpolation(node.name);
+    node.value.andThen(visitExpression);
+    super.visitDeclaration(node);
+  }
+
+  void visitEachRule(EachRule node) {
+    visitExpression(node.list);
+    super.visitEachRule(node);
+  }
+
+  void visitErrorRule(ErrorRule node) {
+    visitExpression(node.expression);
+  }
+
+  void visitExtendRule(ExtendRule node) {
+    visitInterpolation(node.selector);
+  }
+
+  void visitForRule(ForRule node) {
+    visitExpression(node.from);
+    visitExpression(node.to);
+    super.visitForRule(node);
+  }
+
+  void visitIfRule(IfRule node) {
+    for (var clause in node.clauses) {
+      visitExpression(clause.expression);
+      for (var child in clause.children) {
+        child.accept(this);
+      }
+    }
+
+    node.lastClause.andThen((lastClause) {
+      for (var child in lastClause.children) {
+        child.accept(this);
+      }
+    });
+  }
+
+  void visitImportRule(ImportRule node) {
+    for (var import in node.imports) {
+      if (import is StaticImport) {
+        visitInterpolation(import.url);
+        import.supports.andThen(visitSupportsCondition);
+        import.media.andThen(visitInterpolation);
+      }
+    }
+  }
+
+  void visitIncludeRule(IncludeRule node) {
+    visitArgumentInvocation(node.arguments);
+    super.visitIncludeRule(node);
+  }
+
+  void visitLoudComment(LoudComment node) {
+    visitInterpolation(node.text);
+  }
+
+  void visitMediaRule(MediaRule node) {
+    visitInterpolation(node.query);
+    super.visitMediaRule(node);
+  }
+
+  void visitMixinRule(MixinRule node) => visitCallableDeclaration(node);
+
+  void visitReturnRule(ReturnRule node) {
+    visitExpression(node.expression);
+  }
+
+  void visitStyleRule(StyleRule node) {
+    visitInterpolation(node.selector);
+    super.visitStyleRule(node);
+  }
+
+  void visitSupportsRule(SupportsRule node) {
+    visitSupportsCondition(node.condition);
+    super.visitSupportsRule(node);
+  }
+
+  void visitUseRule(UseRule node) {
+    for (var variable in node.configuration) {
+      variable.expression.accept(this);
+    }
+  }
+
+  void visitVariableDeclaration(VariableDeclaration node) {
+    visitExpression(node.expression);
+  }
+
+  void visitWarnRule(WarnRule node) {
+    visitExpression(node.expression);
+  }
+
+  void visitWhileRule(WhileRule node) {
+    visitExpression(node.condition);
+    super.visitWhileRule(node);
+  }
+
   void visitExpression(Expression expression) {
     expression.accept(this);
   }
@@ -76,13 +200,61 @@ abstract class RecursiveAstVisitor extends RecursiveStatementVisitor
     node.operand.accept(this);
   }
 
-  void visitUseRule(UseRule node) {
-    for (var variable in node.configuration) {
-      variable.expression.accept(this);
+  void visitValueExpression(ValueExpression node) {}
+
+  void visitVariableExpression(VariableExpression node) {}
+
+  @protected
+  void visitCallableDeclaration(CallableDeclaration node) {
+    for (var argument in node.arguments.arguments) {
+      argument.defaultValue.andThen(visitExpression);
     }
+    super.visitCallableDeclaration(node);
   }
 
-  void visitValueExpression(ValueExpression node) {}
+  /// Visits each expression in an [invocation].
+  ///
+  /// The default implementation of the visit methods calls this to visit any
+  /// argument invocation in a statement.
+  @protected
+  void visitArgumentInvocation(ArgumentInvocation invocation) {
+    for (var expression in invocation.positional) {
+      visitExpression(expression);
+    }
+    for (var expression in invocation.named.values) {
+      visitExpression(expression);
+    }
+    invocation.rest.andThen(visitExpression);
+    invocation.keywordRest.andThen(visitExpression);
+  }
 
-  void visitVariableExpression(VariableExpression node) {}
+  /// Visits each expression in [condition].
+  ///
+  /// The default implementation of the visit methods call this to visit any
+  /// [SupportsCondition] they encounter.
+  @protected
+  void visitSupportsCondition(SupportsCondition condition) {
+    if (condition is SupportsOperation) {
+      visitSupportsCondition(condition.left);
+      visitSupportsCondition(condition.right);
+    } else if (condition is SupportsNegation) {
+      visitSupportsCondition(condition.condition);
+    } else if (condition is SupportsInterpolation) {
+      visitExpression(condition.expression);
+    } else if (condition is SupportsDeclaration) {
+      visitExpression(condition.name);
+      visitExpression(condition.value);
+    }
+  }
+
+  /// Visits each expression in an [interpolation].
+  ///
+  /// The default implementation of the visit methods call this to visit any
+  /// interpolation in a statement.
+  @protected
+  void visitInterpolation(Interpolation interpolation) {
+    for (var node in interpolation.contents) {
+      if (node is Expression) visitExpression(node);
+    }
+  }
 }