Elements. Migrate ImportAnalyzer and its tests.

Change-Id: Ief9f299769000f4fb6b23354e58c68b2579b0518
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/391302
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Phil Quitslund <[email protected]>

Author: scheglov

pkg/analysis_server/analyzer_use_new_elements.txt

@@ -574,6 +574,7 @@ lib/src/utilities/extensions/range_factory.dart
 lib/src/utilities/extensions/string.dart
 lib/src/utilities/extensions/yaml.dart
 lib/src/utilities/file_string_sink.dart
+lib/src/utilities/import_analyzer.dart
 lib/src/utilities/index_range.dart
 lib/src/utilities/mocks.dart
 lib/src/utilities/null_string_sink.dart
@@ -1454,6 +1455,7 @@ test/src/utilities/extensions/ast_test.dart
 test/src/utilities/extensions/range_factory_test.dart
 test/src/utilities/extensions/string_test.dart
 test/src/utilities/extensions/test_all.dart
+test/src/utilities/import_analyzer_test.dart
 test/src/utilities/json_test.dart
 test/src/utilities/profiling_test.dart
 test/src/utilities/selection_test.dart

pkg/analysis_server/lib/src/services/refactoring/move_top_level_to_file.dart

@@ -12,6 +12,7 @@ import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/source/line_info.dart';
 import 'package:analyzer/source/source_range.dart';
+import 'package:analyzer/src/utilities/extensions/element.dart';
 import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
 import 'package:analyzer_plugin/utilities/change_builder/change_builder_dart.dart';
 import 'package:analyzer_plugin/utilities/range_factory.dart';
@@ -139,7 +140,8 @@ class MoveTopLevelToFile extends RefactoringProducer {
       }
     });
     var libraries = <LibraryElement, Set<Element>>{};
-    for (var element in analyzer.movingDeclarations) {
+    for (var element2 in analyzer.movingDeclarations) {
+      var element = element2.asElement!;
       var matches = await searchEngine.searchReferences(element);
       for (var match in matches) {
         if (match.isResolved) {
@@ -190,15 +192,15 @@ class MoveTopLevelToFile extends RefactoringProducer {
       var element = entry.key;
       var imports = entry.value;
       for (var import in imports) {
-        var library = import.importedLibrary;
+        var library = import.importedLibrary2;
         if (library == null || library.isDartCore) {
           continue;
         }
         var hasShowCombinator =
             import.combinators.whereType<ShowElementCombinator>().isNotEmpty;
         builder.importLibrary(
-          library.source.uri,
-          prefix: import.prefix?.element.name,
+          library.firstFragment.source.uri,
+          prefix: import.prefix2?.element.name,
           showName: element.name,
           useShow: hasShowCombinator,
         );