Cherry Pick: [SuperEditor] - Fix: Paste command remembers the nodes it inserted to play nice with undo/redo (Resolves #2173) (#2234)

Author: github-actions[bot]

super_editor/example/lib/main_super_editor.dart

@@ -18,6 +18,7 @@ void main() {
     // editorImeDeltasLog,
     // editorIosFloatingCursorLog,
     // editorKeyLog,
+    // editorEditsLog,
     // editorOpsLog,
     // editorLayoutLog,
     // editorDocLog,
@@ -178,7 +179,9 @@ class _EditorHistoryPanelState extends State<_EditorHistoryPanel> {
                     titleTextStyle: TextStyle(
                       fontSize: 16,
                     ),
-                    subtitle: Text("${history.changes.map((event) => event.describe()).join("\n")}"),
+                    subtitle: Text(
+                      "${history.commands.map((command) => command.describe()).join("\n\n")}\n-------------\n${history.changes.map((event) => event.describe()).join("\n\n")}",
+                    ),
                     subtitleTextStyle: TextStyle(
                       color: Colors.white.withOpacity(0.5),
                       fontSize: 10,

super_editor/lib/src/core/document_composer.dart

@@ -367,6 +367,10 @@ class ChangeSelectionCommand extends EditCommand {
   void execute(EditContext context, CommandExecutor executor) {
     final composer = context.find<MutableDocumentComposer>(Editor.composerKey);
     final initialSelection = composer.selection;
+    if (initialSelection == newSelection) {
+      // Selection is already where it should be.
+      return;
+    }
 
     composer.setSelectionWithReason(newSelection, reason);
 
@@ -397,7 +401,24 @@ class SelectionChangeEvent extends EditEvent {
   final String reason;
 
   @override
-  String describe() => "Selection - ${changeType.name}, $reason";
+  String describe() {
+    final buffer = StringBuffer("Selection - ${changeType.name}, $reason");
+    if (newSelection == null) {
+      buffer.write(" (SELECTION REMOVED)");
+      return buffer.toString();
+    }
+
+    if (newSelection!.isCollapsed) {
+      buffer.write(" (at ${newSelection!.extent.nodeId} - ${newSelection!.extent.nodePosition}");
+      return buffer.toString();
+    }
+
+    buffer
+      ..writeln("")
+      ..writeln(" - from: ${newSelection!.base.nodeId} - ${newSelection!.base.nodePosition}")
+      ..write(" - to: ${newSelection!.extent.nodeId} - ${newSelection!.extent.nodePosition}");
+    return buffer.toString();
+  }
 
   @override
   String toString() => "[SelectionChangeEvent] - New selection: $newSelection, change type: $changeType";

super_editor/lib/src/core/editor.dart

@@ -410,7 +410,6 @@ class Editor implements RequestDispatcher {
     final changeEvents = <EditEvent>[];
     for (final commandTransaction in _history) {
       for (final command in commandTransaction.commands) {
-        editorEditsLog.finer("Executing command: ${command.runtimeType}");
         // We re-run the commands without tracking changes and without running reactions
         // because any relevant reactions should have run the first time around, and already
         // submitted their commands.

super_editor/lib/src/default_editor/common_editor_operations.dart

@@ -2265,11 +2265,28 @@ class PasteEditorCommand extends EditCommand {
   final String _content;
   final DocumentPosition _pastePosition;
 
+  // The [_content] as [DocumentNode]s so that we only generate node IDs one
+  // time. This is critical for undo behavior to work as expected.
+  List<DocumentNode>? _parsedContent;
+
   @override
   HistoryBehavior get historyBehavior => HistoryBehavior.undoable;
 
   @override
   void execute(EditContext context, CommandExecutor executor) {
+    // Only parse the content if we haven't done it already. This command
+    // might be run 2+ times if the user runs an undo operation.
+    _parsedContent ??= _parseContent();
+
+    // Assign locally so we don't have to use a "!" everywhere we reference it.
+    // Also, make a copy of the existing nodes so that when the document mutates,
+    // our local copy doesn't change.
+    final parsedContent = _parsedContent!.map((node) => node.copy()).toList();
+    if (parsedContent.isEmpty) {
+      // No content to paste.
+      return;
+    }
+
     final document = context.document;
     final composer = context.find<MutableDocumentComposer>(Editor.composerKey);
     final currentNodeWithSelection = document.getNodeById(_pastePosition.nodeId);
@@ -2279,14 +2296,10 @@ class PasteEditorCommand extends EditCommand {
 
     editorOpsLog.info("Pasting clipboard content in document.");
 
-    // Split the pasted content at newlines, and apply attributions based
-    // on inspection of the pasted content, e.g., link attributions.
-    final attributedLines = _inferAttributionsForLinesOfPastedText(_content);
-
     final textNode = document.getNode(_pastePosition) as TextNode;
     final pasteTextOffset = (_pastePosition.nodePosition as TextPosition).offset;
 
-    if (attributedLines.length > 1 && pasteTextOffset < textNode.endPosition.offset) {
+    if (parsedContent.length > 1 && pasteTextOffset < textNode.endPosition.offset) {
       // There is more than 1 node of content being pasted. Therefore,
       // new nodes will need to be added, which means that the currently
       // selected text node will be split at the current text offset.
@@ -2303,20 +2316,20 @@ class PasteEditorCommand extends EditCommand {
       );
     }
 
-    // Paste the first piece of attributed content into the selected TextNode.
-    executor.executeCommand(
-      InsertAttributedTextCommand(
-        documentPosition: _pastePosition,
-        textToInsert: attributedLines.first,
-      ),
-    );
+    if (parsedContent.first is TextNode) {
+      // Paste the first piece of attributed content into the existing selected TextNode.
+      executor.executeCommand(
+        InsertAttributedTextCommand(
+          documentPosition: _pastePosition,
+          textToInsert: (parsedContent.first as TextNode).text,
+        ),
+      );
+    }
 
     // The first line of pasted text was added to the selected paragraph.
-    // Now, create new nodes for each additional line of pasted text and
-    // insert those nodes.
-    final pastedContentNodes = _convertLinesToParagraphs(attributedLines.sublist(1));
+    // Now, add all remaining pasted nodes to the document..
     DocumentNode previousNode = currentNodeWithSelection;
-    for (final pastedNode in pastedContentNodes) {
+    for (final pastedNode in parsedContent.sublist(1)) {
       document.insertNodeAfter(
         existingNode: previousNode,
         newNode: pastedNode,
@@ -2334,17 +2347,10 @@ class PasteEditorCommand extends EditCommand {
     executor.executeCommand(
       ChangeSelectionCommand(
         DocumentSelection.collapsed(
-          position: pastedContentNodes.isNotEmpty
-              ? DocumentPosition(
-                  nodeId: previousNode.id,
-                  nodePosition: previousNode.endPosition,
-                )
-              : DocumentPosition(
-                  nodeId: currentNodeWithSelection.id,
-                  nodePosition: TextNodePosition(
-                    offset: pasteTextOffset + attributedLines.first.text.length,
-                  ),
-                ),
+          position: DocumentPosition(
+            nodeId: previousNode.id,
+            nodePosition: previousNode.endPosition,
+          ),
         ),
         SelectionChangeType.insertContent,
         SelectionReason.userInteraction,
@@ -2354,6 +2360,13 @@ class PasteEditorCommand extends EditCommand {
     editorOpsLog.fine('Done with paste command.');
   }
 
+  List<DocumentNode> _parseContent() {
+    // Split the pasted content at newlines, and apply attributions based
+    // on inspection of the pasted content, e.g., link attributions.
+    final attributedLines = _inferAttributionsForLinesOfPastedText(_content);
+    return _convertLinesToParagraphs(attributedLines).toList();
+  }
+
   /// Breaks the given [content] at each newline, then applies any inferred
   /// attributions based on content analysis, e.g., surrounds URLs with
   /// [LinkAttribution]s.

super_editor/lib/src/default_editor/document_ime/document_delta_editing.dart

@@ -333,11 +333,12 @@ class TextDeltasDocumentEditor {
     editorOpsLog.fine("Executing text insertion command.");
     editorOpsLog.finer("Text before insertion: '${insertionNode.text.text}'");
     editor.execute([
-      ChangeSelectionRequest(
-        DocumentSelection.collapsed(position: insertionPosition),
-        SelectionChangeType.placeCaret,
-        SelectionReason.userInteraction,
-      ),
+      if (selection.value != DocumentSelection.collapsed(position: insertionPosition))
+        ChangeSelectionRequest(
+          DocumentSelection.collapsed(position: insertionPosition),
+          SelectionChangeType.placeCaret,
+          SelectionReason.userInteraction,
+        ),
       InsertTextRequest(
         documentPosition: insertionPosition,
         textToInsert: text,

super_editor/test/super_editor/supereditor_copy_and_paste_test.dart

@@ -1,6 +1,8 @@
 import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter_test_robots/flutter_test_robots.dart';
+import 'package:flutter_test_runners/flutter_test_runners.dart';
 import 'package:super_editor/super_editor.dart';
 import 'package:super_editor/super_editor_test.dart';
 
@@ -90,5 +92,100 @@ This is the third paragraph''');
       expect((doc.getNodeAt(1)! as ParagraphNode).text.text, 'This is a second paragraph');
       expect((doc.getNodeAt(2)! as ParagraphNode).text.text, 'This is the third paragraph');
     });
+
+    testAllInputsOnAllPlatforms("paste retains node IDs when replayed during undo", (
+      tester, {
+      required TextInputSource inputSource,
+    }) async {
+      final testContext = await tester //
+          .createDocument()
+          .withSingleEmptyParagraph()
+          .withInputSource(inputSource)
+          .pump();
+
+      // Place the caret at the empty paragraph.
+      await tester.placeCaretInParagraph('1', 0);
+
+      // Simulate pasting multiple lines.
+      tester
+        ..simulateClipboard()
+        ..setSimulatedClipboardContent('''This is a paragraph
+This is a second paragraph
+This is the third paragraph''');
+      if (defaultTargetPlatform == TargetPlatform.macOS) {
+        await tester.pressCmdV();
+      } else {
+        await tester.pressCtlV();
+      }
+
+      // Gather the current node IDs in the document.
+      final originalNodeIds = testContext.document.toList().map((node) => node.id).toList();
+
+      // Pump enough time to separate the next text entry from the paste action.
+      await tester.pump(const Duration(seconds: 2));
+
+      // Type some text.
+      switch (inputSource) {
+        case TextInputSource.keyboard:
+          await tester.pressKey(LogicalKeyboardKey.keyA);
+        case TextInputSource.ime:
+          await tester.typeImeText("a");
+      }
+
+      // Undo the text insertion (this causes the paste command re-run).
+      testContext.editor.undo();
+
+      // Ensure that the node IDs in the document didn't change after re-running
+      // the paste command.
+      final newNodeIds = testContext.document.toList().map((node) => node.id).toList();
+      expect(newNodeIds, originalNodeIds);
+    });
+
+    testWidgetsOnMac("paste command content does not mutate when document changes", (tester) async {
+      final testContext = await tester //
+          .createDocument()
+          .withSingleEmptyParagraph()
+          .enableHistory(true)
+          .pump();
+
+      // Place the caret at the empty paragraph.
+      await tester.placeCaretInParagraph('1', 0);
+
+      // Simulate pasting multiple lines.
+      tester
+        ..simulateClipboard()
+        ..setSimulatedClipboardContent('''This is a paragraph
+This is a second paragraph
+This is the third paragraph''');
+      if (defaultTargetPlatform == TargetPlatform.macOS) {
+        await tester.pressCmdV();
+      } else {
+        await tester.pressCtlV();
+      }
+
+      // Pump enough time to separate the next text entry from the paste action.
+      await tester.pump(const Duration(seconds: 2));
+      await tester.typeImeText("a");
+
+      // Ensure that the "a" was inserted at the end of the final pasted paragraph.
+      expect(
+        (testContext.document.last as TextNode).text.text,
+        "This is the third paragrapha",
+      );
+
+      // Run undo.
+      testContext.editor.undo();
+
+      // After undo, ensure that we no longer have the inserted "a".
+      //
+      // The undo operation works by replaying earlier commands, such as the paste command.
+      // The paste command internally stores the content that it inserted. This test ensures
+      // that the paste command's internal content wasn't mutated when we inserted the "a"
+      // into the document. Such mutation was part of bug https://github.com/superlistapp/super_editor/issues/2173
+      expect(
+        (testContext.document.last as TextNode).text.text,
+        "This is the third paragraph",
+      );
+    });
   });
 }