[DAS] Fix auto-complete update combinators

We already have a quick-fix that allows us to use the same existing import by editing the combinators. The auto-completer now should do the same.

Bug: Dart-Code/Dart-Code#5238
Change-Id: I0f3a50299abb9890370a6c8934b49036f7e03196
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/404525
Auto-Submit: Felipe Morschel <[email protected]>
Commit-Queue: Phil Quitslund <[email protected]>
Reviewed-by: Phil Quitslund <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: FMorschel

pkg/analysis_server/lib/src/lsp/handlers/handler_completion_resolve.dart

@@ -86,10 +86,17 @@ class CompletionResolveHandler
           return cancelled(token);
         }
 
+        var element =
+            elementReference != null
+                ? await ElementLocation2.decode(
+                  elementReference,
+                ).locateIn(session)
+                : null;
+
         var builder = ChangeBuilder(session: session);
         await builder.addDartFileEdit(file, (builder) {
           for (var uri in importUris) {
-            builder.importLibraryElement(uri);
+            builder.importLibraryElement(uri, showName: element?.name3);
           }
         });
 
@@ -123,12 +130,6 @@ class CompletionResolveHandler
 
         // Look up documentation if we can get an element for this item.
         Either2<MarkupContent, String>? documentation;
-        var element =
-            elementReference != null
-                ? await ElementLocation2.decode(
-                  elementReference,
-                ).locateIn(session)
-                : null;
         if (element != null) {
           var formats = clientCapabilities.completionDocumentationFormats;
           var dartDocInfo = server.getDartdocDirectiveInfoForSession(session);

pkg/analysis_server/lib/src/services/correction/dart/import_library.dart

@@ -96,6 +96,8 @@ class ImportLibrary extends MultiCorrectionProducer {
       for (var instantiatedExtension in instantiatedExtensions) {
         // If the import has a combinator that needs to be updated, then offer
         // to update it.
+        // TODO(FMorschel): We should fix all combinators for the import, if
+        // we don't, we may not import at all.
         var combinators = import.combinators;
         if (combinators.length == 1) {
           var combinator = combinators[0];
@@ -624,7 +626,7 @@ class _ImportAbsoluteLibrary extends ResolvedCorrectionProducer {
         _uriText = builder.importLibraryWithAbsoluteUri(
           _library,
           prefix: _prefix,
-          shownName: _show,
+          showName: _show,
           useShow: _show != null,
         );
       }
@@ -873,7 +875,7 @@ class _ImportRelativeLibrary extends ResolvedCorrectionProducer {
         _uriText = builder.importLibraryWithRelativeUri(
           _library,
           prefix: _prefix,
-          shownName: _show,
+          showName: _show,
           useShow: _show != null,
         );
       }

pkg/analysis_server/test/lsp/completion_dart_test.dart

@@ -3663,6 +3663,131 @@ void f() {
     expect(res.isIncomplete, isTrue);
   }
 
+  Future<void> test_unimportedSymbols_libraryImported_hidingMultiple() async {
+    newFile(join(projectFolderPath, 'lib', 'my_classes.dart'), '''
+class MyClass1 {}
+class MyClass2 {}
+class MyClass3 {}
+''');
+
+    var content = '''
+import 'package:test/my_classes.dart' hide MyClass1, MyClass2;
+void f() {
+  MyClas^
+}
+''';
+
+    var expectedContent = '''
+import 'package:test/my_classes.dart' hide MyClass2;
+void f() {
+  MyClass1
+}
+''';
+
+    var completionLabel = 'MyClass1';
+
+    await _checkCompletionEdits(
+      mainFileUri,
+      content,
+      completionLabel,
+      expectedContent,
+    );
+  }
+
+  Future<void> test_unimportedSymbols_libraryImported_hidingOne() async {
+    newFile(join(projectFolderPath, 'lib', 'my_classes.dart'), '''
+class MyClass1 {}
+class MyClass2 {}
+''');
+
+    var content = '''
+import 'package:test/my_classes.dart' hide MyClass1;
+void f() {
+  MyClas^
+}
+''';
+
+    var expectedContent = '''
+import 'package:test/my_classes.dart';
+void f() {
+  MyClass1
+}
+''';
+
+    var completionLabel = 'MyClass1';
+
+    await _checkCompletionEdits(
+      mainFileUri,
+      content,
+      completionLabel,
+      expectedContent,
+    );
+  }
+
+  Future<void> test_unimportedSymbols_libraryImported_showingOther() async {
+    newFile(join(projectFolderPath, 'lib', 'my_classes.dart'), '''
+class MyClass1 {}
+class MyClass2 {}
+''');
+
+    var content = '''
+import 'package:test/my_classes.dart' show MyClass2;
+void f() {
+  MyClas^
+}
+''';
+
+    var expectedContent = '''
+import 'package:test/my_classes.dart' show MyClass1, MyClass2;
+void f() {
+  MyClass1
+}
+''';
+
+    var completionLabel = 'MyClass1';
+
+    await _checkCompletionEdits(
+      mainFileUri,
+      content,
+      completionLabel,
+      expectedContent,
+    );
+  }
+
+  // Code completion doesn't include prefixes for auto-imports so when an
+  // auto-import is added it must be unprefixed even if the library exists with
+  // a prefix (we cannot modify the inserted text during resolve).
+  Future<void> test_unimportedSymbols_libraryImported_withPrefix() async {
+    newFile(join(projectFolderPath, 'lib', 'my_classes.dart'), '''
+class MyClass1 {}
+class MyClass2 {}
+''');
+
+    var content = '''
+import 'package:test/my_classes.dart' as p1 show MyClass2;
+void f() {
+  MyClas^
+}
+''';
+
+    var expectedContent = '''
+import 'package:test/my_classes.dart' as p1 show MyClass2;
+import 'package:test/my_classes.dart';
+void f() {
+  MyClass1
+}
+''';
+
+    var completionLabel = 'MyClass1';
+
+    await _checkCompletionEdits(
+      mainFileUri,
+      content,
+      completionLabel,
+      expectedContent,
+    );
+  }
+
   /// This test reproduces a bug where the pathKey hash used in
   /// available_declarations.dart would not change with the contents of the file
   /// (as it always used 0 as the modification stamp) which would prevent