Migrate a utility class used by several other libraries

Change-Id: I7f3b67624633fda4e188b30e5b44c304256378ee
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/391204
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>

Author: bwilkerson

pkg/analysis_server/lib/src/services/refactoring/legacy/visible_ranges_computer.dart

@@ -5,17 +5,22 @@
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/dart/element/element2.dart';
 import 'package:analyzer/source/source_range.dart';
 import 'package:analyzer_plugin/utilities/range_factory.dart';
 
 /// Computer of local elements and source ranges in which they are visible.
 class VisibleRangesComputer extends GeneralizingAstVisitor<void> {
   final Map<LocalElement, SourceRange> _map = {};
 
+  final Map<PromotableElement2, SourceRange> _map2 = {};
+
   @override
   void visitCatchClause(CatchClause node) {
-    _addLocalVariable(node, node.exceptionParameter?.declaredElement);
-    _addLocalVariable(node, node.stackTraceParameter?.declaredElement);
+    _addLocalVariable(node, node.exceptionParameter?.declaredElement,
+        node.exceptionParameter?.declaredElement2);
+    _addLocalVariable(node, node.stackTraceParameter?.declaredElement,
+        node.stackTraceParameter?.declaredElement2);
     node.body.accept(this);
   }
 
@@ -30,14 +35,25 @@ class VisibleRangesComputer extends GeneralizingAstVisitor<void> {
         _map[element] = range.node(body);
       }
     }
+
+    var element2 = node.declaredFragment?.element;
+    if (element2 is FormalParameterElement) {
+      var body = _getFunctionBody(node);
+      if (body is BlockFunctionBody) {
+        _map2[element2] = range.node(body);
+      } else if (body is ExpressionFunctionBody) {
+        _map2[element2] = range.node(body);
+      }
+    }
   }
 
   @override
   void visitForPartsWithDeclarations(ForPartsWithDeclarations node) {
     var loop = node.parent;
     if (loop != null) {
       for (var variable in node.variables.variables) {
-        _addLocalVariable(loop, variable.declaredElement);
+        _addLocalVariable(
+            loop, variable.declaredElement, variable.declaredElement2);
         variable.initializer?.accept(this);
       }
     }
@@ -54,21 +70,41 @@ class VisibleRangesComputer extends GeneralizingAstVisitor<void> {
     super.visitFunctionDeclaration(node);
   }
 
+  @override
+  void visitPatternVariableDeclaration(PatternVariableDeclaration node) {
+    // TODO(brianwilkerson): Figure out why this isn't handled.
+    super.visitPatternVariableDeclaration(node);
+  }
+
+  @override
+  void visitPatternVariableDeclarationStatement(
+      PatternVariableDeclarationStatement node) {
+    // TODO(brianwilkerson): Figure out why this isn't handled.
+    super.visitPatternVariableDeclarationStatement(node);
+  }
+
   @override
   void visitVariableDeclarationStatement(VariableDeclarationStatement node) {
     var block = node.parent;
     if (block != null) {
       for (var variable in node.variables.variables) {
-        _addLocalVariable(block, variable.declaredElement);
+        _addLocalVariable(
+            block, variable.declaredElement, variable.declaredElement2);
         variable.initializer?.accept(this);
       }
     }
   }
 
-  void _addLocalVariable(AstNode scopeNode, Element? element) {
+  void _addLocalVariable(
+      AstNode scopeNode, Element? element, Element2? element2) {
     if (element is LocalVariableElement) {
+      // TODO(brianwilkerson): Figure out why this isn't `PromotableElement`. It
+      //  appears to be missing parameter elements.
       _map[element] = range.node(scopeNode);
     }
+    if (element2 is PromotableElement2) {
+      _map2[element2] = range.node(scopeNode);
+    }
   }
 
   static Map<LocalElement, SourceRange> forNode(AstNode unit) {
@@ -77,6 +113,12 @@ class VisibleRangesComputer extends GeneralizingAstVisitor<void> {
     return computer._map;
   }
 
+  static Map<PromotableElement2, SourceRange> forNode2(AstNode unit) {
+    var computer = VisibleRangesComputer();
+    unit.accept(computer);
+    return computer._map2;
+  }
+
   /// Return the body of the function that contains the given [parameter], or
   /// `null` if no function body could be found.
   static FunctionBody? _getFunctionBody(FormalParameter parameter) {