[BUG] - Exception when deleting at beginning of line while composing action tag

[KevinBrendel]

Package Version
super_editor, GitHub, main branch

User Info
coneno, QuikFlow

To Reproduce
Steps to reproduce the behavior:

1. Go to the "Action Tags" section of the example app
2. Create a second ParagraphNode by pressing enter (doesn't matter what is in the first ParagraphNode)
3. Type "/" to start composing an action tag
4. Press left arrow to jump to the beginning of the line
5. Press backspace
6. See exception

Actual behavior

════════ Exception caught by services library ══════════════════════════════════
The following _Exception was thrown during method call TextInputClient.performSelectors:
Exception: No such position in document: [DocumentPosition] - node: "f9e20d51-c9ee-4924-b97b-dfaf0324ed9b", position: (TextPosition(offset: 0, affinity: TextAffinity.downstream))

When the exception was thrown, this was the stack:
#0      MutableDocument.getNodesInside (package:super_editor/src/core/editor.dart:1173:7)
editor.dart:1173
#1      RemoveTextAttributionsCommand.execute (package:super_editor/src/default_editor/text.dart:1376:28)
text.dart:1376
#2      _DocumentEditorCommandExecutor.executeCommand (package:super_editor/src/core/editor.dart:701:15)
editor.dart:701
#3      Editor._executeCommand (package:super_editor/src/core/editor.dart:304:22)
editor.dart:304
#4      Editor.execute (package:super_editor/src/core/editor.dart:266:30)
editor.dart:266
#5      ActionTagComposingReaction._cancelComposingTag (package:super_editor/src/default_editor/text_tokenizing/action_tags.dart:437:23)
action_tags.dart:437
#6      ActionTagComposingReaction.react (package:super_editor/src/default_editor/text_tokenizing/action_tags.dart:325:7)
action_tags.dart:325
#7      Editor._reactToChanges (package:super_editor/src/core/editor.dart:357:16)
editor.dart:357
#8      Editor.endTransaction (package:super_editor/src/core/editor.dart:222:5)
editor.dart:222
#9      Editor.execute (package:super_editor/src/core/editor.dart:283:7)
editor.dart:283
#10     CommonEditorOperations.mergeTextNodeWithUpstreamTextNode (package:super_editor/src/default_editor/common_editor_operations.dart:1187:12)
common_editor_operations.dart:1187
#11     CommonEditorOperations.deleteUpstream (package:super_editor/src/default_editor/common_editor_operations.dart:1109:18)
common_editor_operations.dart:1109
#12     deleteBackward (package:super_editor/src/default_editor/document_ime/supereditor_ime_interactor.dart:709:21)
supereditor_ime_interactor.dart:709
#13     SuperEditorImeInteractorState._onPerformSelector (package:super_editor/src/default_editor/document_ime/supereditor_ime_interactor.dart:472:12)
supereditor_ime_interactor.dart:472
#14     DocumentImeInputClient.performSelector (package:super_editor/src/default_editor/document_ime/document_ime_communication.dart:305:22)
document_ime_communication.dart:305
#15     DeltaTextInputClientDecorator.performSelector (package:super_editor/src/default_editor/document_ime/ime_decoration.dart:104:14)
ime_decoration.dart:104
#16     ListBase.forEach (dart:collection/list.dart:51:13)
list.dart:51
#17     TextInput._handleTextInputInvocation (package:flutter/src/services/text_input.dart:1916:19)
text_input.dart:1916
#18     TextInput._loudlyHandleTextInputInvocation (package:flutter/src/services/text_input.dart:1794:20)
text_input.dart:1794
#19     MethodChannel._handleAsMethodCall (package:flutter/src/services/platform_channel.dart:571:55)
platform_channel.dart:571
#20     MethodChannel.setMethodCallHandler.<anonymous closure> (package:flutter/src/services/platform_channel.dart:564:34)
platform_channel.dart:564
#21     _DefaultBinaryMessenger.setMessageHandler.<anonymous closure> (package:flutter/src/services/binding.dart:581:35)
binding.dart:581
#22     _invoke2 (dart:ui/hooks.dart:344:13)
hooks.dart:344
#23     _ChannelCallbackRecord.invoke (dart:ui/channel_buffers.dart:45:5)
channel_buffers.dart:45
#24     _Channel.push (dart:ui/channel_buffers.dart:135:31)
channel_buffers.dart:135
#25     ChannelBuffers.push (dart:ui/channel_buffers.dart:343:17)
channel_buffers.dart:343
#26     PlatformDispatcher._dispatchPlatformMessage (dart:ui/platform_dispatcher.dart:750:22)
platform_dispatcher.dart:750
#27     _dispatchPlatformMessage (dart:ui/hooks.dart:257:31)
hooks.dart:257

call: MethodCall(TextInputClient.performSelectors, [1, [deleteBackward:]])
════════════════════════════════════════════════════════════════════════════════

Expected behavior
The action tag is cancelled, the "line break" is deleted, and the cancelled "/" is appended to the previous ParagraphNode.

Platform
macOS

Flutter version
Flutter 3.22.3 • channel stable • https://github.com/flutter/flutter.git
Framework • revision b0850beeb2 (4 weeks ago) • 2024-07-16 21:43:41 -0700
Engine • revision 235db911ba
Tools • Dart 3.4.4 • DevTools 2.34.3

Screenshots