Issue 24487. Annotations with constructor resolution should produce navigation reginos to construct…

pkg/analysis_server/lib/src/domains/analysis/navigation_dart.dart

Index: pkg/analysis_server/lib/src/domains/analysis/navigation_dart.dart
diff --git a/pkg/analysis_server/lib/src/domains/analysis/navigation_dart.dart b/pkg/analysis_server/lib/src/domains/analysis/navigation_dart.dart
index 8b87629949fc819391227faa702bb83315cd2440..f1b9100628e1ab0a4d52f49639a718c8f8bf63c4 100644
--- a/pkg/analysis_server/lib/src/domains/analysis/navigation_dart.dart
+++ b/pkg/analysis_server/lib/src/domains/analysis/navigation_dart.dart
@@ -74,6 +74,9 @@ class _DartNavigationCollector {
   }
 
   void _addRegionForNode(AstNode node, Element element) {
+    if (node == null) {
+      return;
+    }
     int offset = node.offset;
     int length = node.length;
     _addRegion(offset, length, element);
@@ -92,6 +95,30 @@ class _DartNavigationComputerVisitor extends RecursiveAstVisitor {
   _DartNavigationComputerVisitor(this.computer);
 
   @override
+  visitAnnotation(Annotation node) {
+    Element element = node.element;
+    if (element is ConstructorElement && element.isSynthetic) {
+      element = element.enclosingElement;
+    }
+    Identifier name = node.name;
+    if (name is PrefixedIdentifier) {
+      // use constructor in: @PrefixClass.constructorName
+      Element prefixElement = name.prefix.staticElement;
+      if (prefixElement is ClassElement) {
+        prefixElement = element;
+      }
+      computer._addRegionForNode(name.prefix, prefixElement);
+      // always constructor
+      computer._addRegionForNode(name.identifier, element);
+    } else {
+      computer._addRegionForNode(name, element);
+    }
+    computer._addRegionForNode(node.constructorName, element);
+    // arguments
+    _safelyVisit(node.arguments);
+  }
+
+  @override
   visitAssignmentExpression(AssignmentExpression node) {
     _safelyVisit(node.leftHandSide);
     computer._addRegionForToken(node.operator, node.bestElement);