Elements. Migrate BestPracticesVerifier.

Change-Id: Ib2ac5ed4cd5a82fc2b880a5a56465d04ebbbbf43
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/409383
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Reviewed-by: Phil Quitslund <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/dart/element/extensions.dart

@@ -22,6 +22,32 @@ extension DartTypeExtension on DartType {
 }
 
 extension Element2Extension on Element2 {
+  /// Return `true` if this element, the enclosing class (if there is one), or
+  /// the enclosing library, has been annotated with the `@doNotStore`
+  /// annotation.
+  bool get hasOrInheritsDoNotStore {
+    if (this case Annotatable annotatable) {
+      if (annotatable.metadata2.hasDoNotStore) {
+        return true;
+      }
+    }
+
+    var ancestor = enclosingElement2;
+    if (ancestor is InterfaceElement2) {
+      if (ancestor.metadata2.hasDoNotStore) {
+        return true;
+      }
+      ancestor = ancestor.enclosingElement2;
+    } else if (ancestor is ExtensionElement2) {
+      if (ancestor.metadata2.hasDoNotStore) {
+        return true;
+      }
+      ancestor = ancestor.enclosingElement2;
+    }
+
+    return ancestor is LibraryElement2 && ancestor.metadata2.hasDoNotStore;
+  }
+
   /// Return `true` if this element is an instance member of a class or mixin.
   ///
   /// Only [MethodElement2]s, [GetterElement]s, and  [SetterElement]s are

pkg/analyzer/lib/src/dart/resolver/scope.dart

@@ -180,6 +180,23 @@ class NamespaceBuilder {
     return Namespace(exportedNames);
   }
 
+  /// Create a namespace representing the export namespace of the given
+  /// [export].
+  Namespace createExportNamespaceForDirective2(LibraryExport export) {
+    var exportedLibrary = export.exportedLibrary2;
+    if (exportedLibrary == null) {
+      //
+      // The exported library will be null if the URI does not reference a valid
+      // library.
+      //
+      return Namespace.EMPTY;
+    }
+    Map<String, Element> exportedNames =
+        _getExportMapping(exportedLibrary.asElement);
+    exportedNames = _applyCombinators(exportedNames, export.combinators);
+    return Namespace(exportedNames);
+  }
+
   /// Create a namespace representing the export namespace of the given
   /// [library].
   Namespace createExportNamespaceForLibrary(LibraryElement2 library) {