Issue 29288. Resynthesize Import/Export/PartElement for every directive.

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

 // Copyright (c) 2014, 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.
 
 library analyzer.src.dart.element.element;
 
 import 'dart:collection';
 import 'dart:math' show min;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 5862 matching lines @@
       List<UnlinkedExportPublic> unlinkedPublicExports =
           _unlinkedDefiningUnit.publicNamespace.exports;
       assert(
           _unlinkedDefiningUnit.exports.length == unlinkedPublicExports.length);
       int length = unlinkedNonPublicExports.length;
       if (length != 0) {
         List<ExportElement> exports = new List<ExportElement>();
         for (int i = 0; i < length; i++) {
           UnlinkedExportPublic serializedExportPublic =
               unlinkedPublicExports[i];
-          LibraryElement exportedLibrary = resynthesizerContext
-              .buildExportedLibrary(serializedExportPublic.uri);
-          if (exportedLibrary != null) {
-            UnlinkedExportNonPublic serializedExportNonPublic =
-                unlinkedNonPublicExports[i];
-            ExportElementImpl exportElement =
-                new ExportElementImpl.forSerialized(
-                    serializedExportPublic, serializedExportNonPublic, library);
-            exports.add(exportElement);
-          }
+          UnlinkedExportNonPublic serializedExportNonPublic =
+              unlinkedNonPublicExports[i];
+          ExportElementImpl exportElement = new ExportElementImpl.forSerialized(
+              serializedExportPublic, serializedExportNonPublic, library);
+          exports.add(exportElement);
         }
         _exports = exports;
       } else {
         _exports = const <ExportElement>[];
       }
     }
     return _exports ?? const <ExportElement>[];
   }
 
   /**
@@ skipping 60 matching lines @@
   @override
   List<ImportElement> get imports {
     if (_unlinkedDefiningUnit != null && _imports == null) {
       List<UnlinkedImport> unlinkedImports = _unlinkedDefiningUnit.imports;
       int length = unlinkedImports.length;
       if (length != 0) {
         List<ImportElement> imports = new List<ImportElement>();
         LinkedLibrary linkedLibrary = resynthesizerContext.linkedLibrary;
         for (int i = 0; i < length; i++) {
           int dependency = linkedLibrary.importDependencies[i];
-          LibraryElement importedLibrary =
-              resynthesizerContext.buildImportedLibrary(dependency);
-          if (importedLibrary != null) {
-            ImportElementImpl importElement =
-                new ImportElementImpl.forSerialized(
-                    unlinkedImports[i], dependency, library);
-            imports.add(importElement);
-          }
+          ImportElementImpl importElement = new ImportElementImpl.forSerialized(
+              unlinkedImports[i], dependency, library);
+          imports.add(importElement);
         }
         _imports = imports;
       } else {
         _imports = const <ImportElement>[];
       }
     }
     return _imports ?? ImportElement.EMPTY_LIST;
   }
 
   /**
@@ skipping 3103 matching lines @@
 
   @override
   void visitElement(Element element) {
     int offset = element.nameOffset;
     if (offset != -1) {
       map[offset] = element;
     }
     super.visitElement(element);
   }
 }