Update imports in files other than the source and destination when moving declarations

Change-Id: I3675bddc9479744a4642bdbb66b8de013f0f01df
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/273524
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/lib/src/services/refactoring/framework/refactoring_context.dart

@@ -5,6 +5,7 @@
 import 'package:analysis_server/src/lsp/lsp_analysis_server.dart';
 import 'package:analysis_server/src/services/correction/change_workspace.dart';
 import 'package:analysis_server/src/services/correction/util.dart';
+import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/analysis/session.dart';
 import 'package:analyzer/dart/ast/ast.dart';
@@ -53,6 +54,9 @@ class RefactoringContext {
     required this.selectionLength,
   });
 
+  /// Return the search engine used to search outside the resolved library.
+  SearchEngine get searchEngine => server.searchEngine;
+
   /// Return the analysis session in which additional resolution can occur.
   AnalysisSession get session => resolvedUnitResult.session;
 }

pkg/analysis_server/lib/src/services/refactoring/framework/refactoring_producer.dart

@@ -6,6 +6,7 @@ import 'package:analysis_server/lsp_protocol/protocol_custom_generated.dart';
 import 'package:analysis_server/lsp_protocol/protocol_generated.dart';
 import 'package:analysis_server/src/services/correction/util.dart';
 import 'package:analysis_server/src/services/refactoring/framework/refactoring_context.dart';
+import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ -34,6 +35,9 @@ abstract class RefactoringProducer {
   /// Return a list of the parameters to send to the client.
   List<CommandParameter> get parameters;
 
+  /// Return the search engine used to search outside the resolved library.
+  SearchEngine get searchEngine => _context.searchEngine;
+
   /// Return the node that was selected, or `null` if the selection is not
   /// valid.
   AstNode? get selectedNode => _context.selectedNode;

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

@@ -2,11 +2,13 @@
 // 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.
 
-import 'package:analysis_server/lsp_protocol/protocol_custom_generated.dart';
+import 'package:analysis_server/lsp_protocol/protocol_custom_generated.dart'
+    show CommandParameter, SaveUriCommandParameter;
 import 'package:analysis_server/src/services/refactoring/framework/refactoring_producer.dart';
 import 'package:analysis_server/src/utilities/extensions/ast.dart';
 import 'package:analysis_server/src/utilities/import_analyzer.dart';
 import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/element/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';
@@ -138,8 +140,47 @@ class MoveTopLevelToFile extends RefactoringProducer {
       }
       builder.addDeletion(range.deletionRange(member.node));
     });
-    // TODO(brianwilkerson) Find references to the moved declaration(s) outside
-    //  the source library and update the imports in those files.
+    // TODO(brianwilkerson) This doesn't correctly handle prefixes. In order to
+    //  use the correct prefix when adding the import we need to either
+    //  - enhance SearchMatch to know the prefix used for a reference match, or
+    //  - look at the imports for the library to find the imports that might
+    //    have been used to import the `element` and create a corresponding
+    //    import of the new library for each of them.
+    //
+    //  The latter has the disadvantage that we might end up adding more imports
+    //  than are actually required because we can't know whether they're all
+    //  needed.
+    var libraries = <LibraryElement, Set<Element>>{};
+    for (var element in analyzer.movingDeclarations) {
+      var matches = await searchEngine.searchReferences(element);
+      for (var match in matches) {
+        if (match.isResolved) {
+          libraries.putIfAbsent(match.libraryElement, () => {}).add(element);
+        }
+      }
+    }
+
+    /// Don't update the library from which the code is being moved because
+    /// that's already been done.
+    libraries.remove(libraryResult.element);
+    for (var entry in libraries.entries) {
+      var library = entry.key;
+      var prefixes = <String>{};
+      for (var element in entry.value) {
+        var prefixList =
+            await searchEngine.searchPrefixesUsedInLibrary(library, element);
+        prefixes.addAll(prefixList);
+      }
+      await builder.addDartFileEdit(library.source.fullName, (builder) {
+        for (var prefix in prefixes) {
+          if (prefix.isEmpty) {
+            builder.importLibrary(destinationImportUri);
+          } else {
+            builder.importLibrary(destinationImportUri, prefix: prefix);
+          }
+        }
+      });
+    }
   }
 
   @override

pkg/analysis_server/lib/src/services/search/search_engine.dart

@@ -92,6 +92,12 @@ abstract class SearchEngine {
   /// [name] - the name being referenced by the found matches.
   Future<List<SearchMatch>> searchMemberReferences(String name);
 
+  /// Return the prefixes used to reference the [element] in any of the
+  /// compilation units in the [library]. The returned set will include an empty
+  /// string if the element is referenced without a prefix.
+  Future<Set<String>> searchPrefixesUsedInLibrary(
+      LibraryElement library, Element element);
+
   /// Returns references to the given [Element].
   ///
   /// [element] - the [Element] being referenced by the found matches.

pkg/analysis_server/lib/src/services/search/search_engine_internal.dart

@@ -5,7 +5,9 @@
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
+import 'package:analyzer/src/dart/analysis/driver_based_analysis_context.dart';
 import 'package:analyzer/src/dart/analysis/search.dart';
+import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/generated/source.dart' show Source, SourceRange;
 import 'package:analyzer/src/util/performance/operation_performance.dart';
 
@@ -103,6 +105,14 @@ class SearchEngineImpl implements SearchEngine {
     return allResults.map(SearchMatchImpl.forSearchResult).toList();
   }
 
+  @override
+  Future<Set<String>> searchPrefixesUsedInLibrary(
+      covariant LibraryElementImpl library, Element element) async {
+    var driver =
+        (library.session.analysisContext as DriverBasedAnalysisContext).driver;
+    return await driver.search.prefixesUsedInLibrary(library, element);
+  }
+
   @override
   Future<List<SearchMatch>> searchReferences(Element element) async {
     var allResults = <SearchResult>[];

pkg/analysis_server/test/src/services/refactoring/move_top_level_to_file_test.dart

@@ -299,6 +299,129 @@ class B {}
         newFileContent: newFileContent);
   }
 
+  Future<void> test_imports_referenceInThirdFile_noPrefix() async {
+    var originalSource = '''
+class A {}
+
+class B^ {}
+''';
+    var modifiedSource = '''
+class A {}
+''';
+    var declarationName = 'B';
+    var newFileName = 'b.dart';
+    var newFileContent = '''
+class B {}
+''';
+    var otherFilePath = '$projectFolderPath/lib/c.dart';
+    var otherFileContent = '''
+import 'package:test/main.dart';
+
+B? b;
+''';
+    var modifiedOtherFileContent = '''
+import 'package:test/b.dart';
+import 'package:test/main.dart';
+
+B? b;
+''';
+    await _singleDeclaration(
+        originalSource: originalSource,
+        modifiedSource: modifiedSource,
+        declarationName: declarationName,
+        newFileName: newFileName,
+        newFileContent: newFileContent,
+        otherFilePath: otherFilePath,
+        otherFileContent: otherFileContent,
+        modifiedOtherFileContent: modifiedOtherFileContent);
+  }
+
+  @failingTest
+  Future<void> test_imports_referenceInThirdFile_withMultiplePrefixes() async {
+    // This fails for two reasons:
+    // 1. The indexer isn't recording when a top-level element is referenced
+    //    without a prefix.
+    // 2. The method `DartFileEditBuilderImpl._importLibrary` doesn't support
+    //    importing the same URI with multiple prefixes.
+    var originalSource = '''
+class A {}
+
+class B^ {}
+''';
+    var modifiedSource = '''
+class A {}
+''';
+    var declarationName = 'B';
+    var newFileName = 'b.dart';
+    var newFileContent = '''
+class B {}
+''';
+    var otherFilePath = '$projectFolderPath/lib/c.dart';
+    var otherFileContent = '''
+import 'package:test/main.dart';
+import 'package:test/main.dart' as p;
+import 'package:test/main.dart' as q;
+
+void f(p.B b, q.B b, B b) {}
+''';
+    var modifiedOtherFileContent = '''
+import 'package:test/b.dart';
+import 'package:test/b.dart' as p;
+import 'package:test/b.dart' as q;
+import 'package:test/main.dart';
+import 'package:test/main.dart' as p;
+import 'package:test/main.dart' as q;
+
+void f(p.B b, q.B b, B b) {}
+''';
+    await _singleDeclaration(
+        originalSource: originalSource,
+        modifiedSource: modifiedSource,
+        declarationName: declarationName,
+        newFileName: newFileName,
+        newFileContent: newFileContent,
+        otherFilePath: otherFilePath,
+        otherFileContent: otherFileContent,
+        modifiedOtherFileContent: modifiedOtherFileContent);
+  }
+
+  Future<void> test_imports_referenceInThirdFile_withSinglePrefix() async {
+    var originalSource = '''
+class A {}
+
+class B^ {}
+''';
+    var modifiedSource = '''
+class A {}
+''';
+    var declarationName = 'B';
+    var newFileName = 'b.dart';
+    var newFileContent = '''
+class B {}
+''';
+    var otherFilePath = '$projectFolderPath/lib/c.dart';
+    var otherFileContent = '''
+import 'package:test/main.dart' as p;
+
+p.B? b;
+''';
+    var modifiedOtherFileContent = '''
+import 'package:test/b.dart' as p;
+import 'package:test/main.dart' as p;
+
+p.B? b;
+''';
+    await _singleDeclaration(
+        originalSource: originalSource,
+        modifiedSource: modifiedSource,
+        declarationName: declarationName,
+        newFileName: newFileName,
+        newFileContent: newFileContent,
+        otherFilePath: otherFilePath,
+        otherFileContent: otherFileContent,
+        modifiedOtherFileContent: modifiedOtherFileContent);
+  }
+
   Future<void> test_mixin() async {
     var originalSource = '''
 class A {}
@@ -394,8 +517,14 @@ int variableToMove = 3;
       required String modifiedSource,
       required String declarationName,
       required String newFileName,
-      required String newFileContent}) async {
+      required String newFileContent,
+      String? otherFilePath,
+      String? otherFileContent,
+      String? modifiedOtherFileContent}) async {
     addTestSource(originalSource);
+    if (otherFilePath != null) {
+      addSource(otherFilePath, otherFileContent!);
+    }
 
     /// Expected new file path/content.
     final expectedNewFilePath = join(projectFolderPath, 'lib', newFileName);
@@ -409,5 +538,8 @@ int variableToMove = 3;
     // was sent, the executeRefactor helper would've thrown when trying to
     // apply the changes.
     expect(content[expectedNewFilePath], newFileContent);
+    if (modifiedOtherFileContent != null) {
+      expect(content[otherFilePath!], modifiedOtherFileContent);
+    }
   }
 }

pkg/analyzer/lib/src/dart/analysis/search.dart

@@ -264,6 +264,24 @@ class Search {
     return elements;
   }
 
+  /// Return the prefixes used to reference the [element] in any of the
+  /// compilation units in the [library]. The returned set will include an empty
+  /// string if the element is referenced without a prefix.
+  Future<Set<String>> prefixesUsedInLibrary(
+      LibraryElementImpl library, Element element) async {
+    var prefixes = <String>{};
+    for (var unit in library.units) {
+      var index = await _driver.getIndex(unit.source.fullName);
+      if (index != null) {
+        _IndexRequest request = _IndexRequest(index);
+        int elementId = request.findElementId(element);
+        var prefixList = index.elementImportPrefixes[elementId].split(',');
+        prefixes.addAll(prefixList);
+      }
+    }
+    return prefixes;
+  }
+
   /// Returns references to the [element].
   Future<List<SearchResult>> references(
       Element? element, SearchedFiles searchedFiles) async {