Create missing override(s) quickfix not showing for empty classes.

[pitriq]

Describe the bug

When creating an empty class that extends another one, the "Create n missing override(s)" quickfix is not appearing. In fact vscode says there are no quickfixes available at all. Once I write a single character inside the class, quickfixes start showing up.

This does not happen when using implements.

I'm not sure whether this is an extension or a language server issue. Feel free to close this and refer me to the correct repo.

To Reproduce

Steps to reproduce the behavior:

1. Create an empty class that extends another class that has abstract methods.
2. Press cmd+. anywhere in the class name.

Expected behavior

It should display the appropriate quickfixes.

Screenshots

Please complete the following information:

• Operating System and version: macOS 12.6
• VS Code version: 1.71.2
• Dart extension version: v3.49.20220926
• Dart/Flutter SDK version: dart 2.18.1, Flutter 3.3.2 stable

These are the the logs of pressing cmd+. on the empty class' name, captured with Dart: Capture Analysis Server Logs.

Details

!! PLEASE REVIEW THIS LOG FOR SENSITIVE INFORMATION BEFORE SHARING !!

Dart Code extension: 3.49.20220926
Flutter extension: 3.48.0 (activated)

App: Visual Studio Code
Version: 1.71.2
Platform: mac

Workspace type: Flutter
Analyzer type: LSP
Multi-root?: true

Dart SDK:
Loc: LOCATION
Ver: 2.18.1
Flutter SDK:
Loc: LOCATION
Ver: 3.3.2

HTTP_PROXY: undefined
NO_PROXY: undefined

Logging Categories:
General, Analyzer, CommandProcesses

Tue Sep 27 2022 [10:19:46 GMT-0300 (Argentina Standard Time)] Log file started
[10:19:57 AM] [Analyzer] [Info] ==> Content-Length: 742
[10:19:57 AM] [Analyzer] [Info] ==> {"jsonrpc":"2.0","id":49,"method":"textDocument/codeAction","params":{"textDocument":{"uri":"FILE_URI"},"range":{"start":{"line":2,"character":8},"end":{"line":2,"character":8}},"context":{"diagnostics":[{"range":{"start":{"line":2,"character":6},"end":{"line":2,"character":9}},"message":"Missing concrete implementations of 'CustomPainter.paint' and 'CustomPainter.shouldRepaint'.\nTry implementing the missing methods, or make the class abstract.","code":"non_abstract_class_inherits_abstract_member","codeDescription":{"href":"file:///diagnostics/non_abstract_class_inherits_abstract_member"},"severity":1,"source":"dart"}],"triggerKind":1}},"clientRequestTime":1664284797019}
[10:19:57 AM] [Analyzer] [Info] <== Content-Length: 126
Content-Type: application/vscode-jsonrpc; charset=utf-8
[10:19:57 AM] [Analyzer] [Info] <== {"id":49,"jsonrpc":"2.0","error":{"code":-32001,"message":"An error occurred while handling textDocument/codeAction request"}}
[10:19:57 AM] [Analyzer] [Info] <== Content-Length: 2800
Content-Type: application/vscode-jsonrpc; charset=utf-8

{"jsonrpc":"2.0","method":"window/logMessage","params":{"message":"An error occurred while handling textDocument/codeAction request: RangeError (end): Invalid value: Not in inclusive range 27..232: 26\n#0 RangeError.checkValidRange (dart:core/errors.dart:363:9)\n#1 _StringBase.substring (dart:core-patch/string_patch.dart:400:27)\n#2 SnippetBuilderExtensions.appendPlaceholders (package:analysis_server/src/lsp/snippets.dart:332:23)\n#3 _buildSnippetString (package:analysis_server/src/lsp/snippets.dart:135:7)\n#4 buildSnippetStringForEditGroups (package:analysis_server/src/lsp/snippets.dart:26:5)\n#5 snippetTextEditFromEditGroups (package:analysis_server/src/lsp/mapping.dart:928:14)\n#6 toSnippetTextEdits (package:analysis_server/src/lsp/mapping.dart:1508:22)\n#7 createWorkspaceEdit (package:analysis_server/src/lsp/mapping.dart:150:24)\n#8 CodeActionHandler._createFixAction (package:analysis_server/src/lsp/handlers/handler_code_actions.dart:226:13)\n#9 CodeActionHandler._getFixActions. (package:analysis_server/src/lsp/handlers/handler_code_actions.dart:423:30)\n#10 MappedListIterable.elementAt (dart:_internal/iterable.dart:413:31)\n#11 ListIterator.moveNext (dart:_internal/iterable.dart:342:26)\n#12 List.addAll (dart:core-patch/growable_array.dart:319:13)\n#13 CodeActionHandler._getFixActions (package:analysis_server/src/lsp/handlers/handler_code_actions.dart:421:23)\n\n#14 OperationPerformanceImpl.runAsync (package:analyzer/src/util/performance/operation_performance.dart:164:18)\n\n#15 Future.wait. (dart:async/future.dart:522:21)\n\n#16 CodeActionHandler._getCodeActions (package:analysis_server/src/lsp/handlers/handler_code_actions.dart:350:21)\n\n#17 OperationPerforma…
Tue Sep 27 2022 [10:20:02 GMT-0300 (Argentina Standard Time)] Log file ended

[DanTup]

Thanks, I can reproduce this. Something seems odd with the edits being produced, there's a selection from 0-27 in the edit, which covers the range "\n @override\n void paint(C" which doesn't make sense, and the C at the end clashes with an edit group for Canvas.

{
	"message": "Create 2 missing overrides",
	"edits": [
		{
			"file": "/Users/danny/Dev/TestStuff/flutter_counter/lib/dc4184.dart",
			"fileStamp": 0,
			"edits": [
				{
					"offset": 74,
					"length": 0,
					"replacement": "\n  @override\n  void paint(Canvas canvas, Size size) {\n    // TODO: implement paint\n  }\n\n  @override\n  bool shouldRepaint(covariant CustomPainter oldDelegate) {\n    // TODO: implement shouldRepaint\n    throw UnimplementedError();\n  }\n"
				}
			]
		}
	],
	"linkedEditGroups": [
		{
			"positions": [
				{
					"file": "/Users/danny/Dev/TestStuff/flutter_counter/lib/dc4184.dart",
					"offset": 100
				}
			],
			"length": 6,
			"suggestions": [
				{
					"value": "Canvas",
					"kind": "TYPE"
				},
				{
					"value": "Object",
					"kind": "TYPE"
				}
			]
		},
		{
			"positions": [
				{
					"file": "/Users/danny/Dev/TestStuff/flutter_counter/lib/dc4184.dart",
					"offset": 107
				}
			],
			"length": 6,
			"suggestions": []
		},
		{
			"positions": [
				{
					"file": "/Users/danny/Dev/TestStuff/flutter_counter/lib/dc4184.dart",
					"offset": 115
				}
			],
			"length": 4,
			"suggestions": [
				{
					"value": "Size",
					"kind": "TYPE"
				},
				{
					"value": "OffsetBase",
					"kind": "TYPE"
				},
				{
					"value": "Object",
					"kind": "TYPE"
				}
			]
		},
		{
			"positions": [
				{
					"file": "/Users/danny/Dev/TestStuff/flutter_counter/lib/dc4184.dart",
					"offset": 120
				}
			],
			"length": 4,
			"suggestions": []
		},
		{
			"positions": [
				{
					"file": "/Users/danny/Dev/TestStuff/flutter_counter/lib/dc4184.dart",
					"offset": 205
				}
			],
			"length": 13,
			"suggestions": [
				{
					"value": "CustomPainter",
					"kind": "TYPE"
				},
				{
					"value": "Listenable",
					"kind": "TYPE"
				},
				{
					"value": "Object",
					"kind": "TYPE"
				}
			]
		},
		{
			"positions": [
				{
					"file": "/Users/danny/Dev/TestStuff/flutter_counter/lib/dc4184.dart",
					"offset": 219
				}
			],
			"length": 11,
			"suggestions": []
		}
	],
	"selection": {
		"file": "/Users/danny/Dev/TestStuff/flutter_counter/lib/dc4184.dart",
		"offset": 74
	},
	"selectionLength": 27,
	"id": "dart.fix.create.missingOverrides"
}

[pitriq]

Oh ok, so this is a problem with CustomPainter in particular. Maybe I should rename the issue.

Thanks for looking into it :)

[DanTup]

@pitriq it's not specific to CustomPainter, but depending on the exact names or the overrides being produced, it may/may not be triggered. In some cases, it will work, but the selected text will be incorrect. In this case, the selected text clashes with an edit group and that causes an exception.

I've tracked down the cause (and found a few similar related issues) and just working on some tests. The issue is in the Dart SDK, so the fix will ultimately ship with an SDK update rather than a Dart-Code update.

[DanTup]

Fixed by dart-lang/sdk@d97c3e8. Will ship in a future Dart SDK.