Error when running dart fix (Bad state: Missing a visit method for a node of type PatternAssignmentImpl)

[Yegair]

Just encountered this error when running dart fix --dry-run. Since I was prompted to do so, I opened this ticket.

I have to add that I tried dart fix --apply next which completed without an error, and since then I can no longer reproduce the issue (dart fix --dry-run no longer throws an error).

dart fix --dry-run
Computing fixes in app (dry run)...  
An unexpected error was encountered by the Analysis Server.
Please file an issue at https://github.com/dart-lang/sdk/issues/new/choose with the following details:

Internal error: Exception while using a UseBuildContextSynchronously to visit a MethodInvocationImpl in MethodInvocationImpl in ExpressionStatementImpl in BlockImpl in BlockFunctionBodyImpl in MethodDeclarationImpl in ClassDeclarationImpl in CompilationUnitImpl
Bad state: Missing a visit method for a node of type PatternAssignmentImpl
#0      ExitDetector.visitNode (package:analyzer/src/dart/resolver/exit_detector.dart:455:5)
#1      GeneralizingAstVisitor.visitCollectionElement (package:analyzer/dart/ast/visitor.dart:216:56)
#2      GeneralizingAstVisitor.visitExpression (package:analyzer/dart/ast/visitor.dart:313:42)
#3      GeneralizingAstVisitor.visitPatternAssignment (package:analyzer/dart/ast/visitor.dart:590:56)
#4      PatternAssignmentImpl.accept (package:analyzer/src/dart/ast/ast.dart:13465:50)
#5      ExitDetector._nodeExits (package:analyzer/src/dart/resolver/exit_detector.dart:663:17)
#6      ExitDetector.visitExpressionStatement (package:analyzer/src/dart/resolver/exit_detector.dart:178:7)
#7      ExpressionStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:6186:50)
#8      _extension#6.terminatesControl (package:linter/src/rules/use_build_context_synchronously.dart:1390:12)
#9      _extension#2.terminatesControl (package:linter/src/rules/use_build_context_synchronously.dart:1310:32)
#10     AsyncStateVisitor._visitIfLike (package:linter/src/rules/use_build_context_synchronously.dart:891:39)
#11     AsyncStateVisitor.visitIfStatement (package:linter/src/rules/use_build_context_synchronously.dart:470:53)
#12     IfStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:9378:50)
#13     AsyncStateVisitor._inOrderAsyncState (package:linter/src/rules/use_build_context_synchronously.dart:771:29)
#14     AsyncStateVisitor._inOrderAsyncStateGuardable (package:linter/src/rules/use_build_context_synchronously.dart:788:7)
#15     AsyncStateVisitor._visitBlockLike (package:linter/src/rules/use_build_context_synchronously.dart:799:35)
#16     AsyncStateVisitor.visitBlock (package:linter/src/rules/use_build_context_synchronously.dart:335:7)
#17     BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:2087:50)
#18     AsyncStateTracker.asyncStateFor (package:linter/src/rules/use_build_context_synchronously.dart:114:24)
#19     _Visitor.check (package:linter/src/rules/use_build_context_synchronously.dart:1097:42)
#20     _Visitor._visitArgumentList (package:linter/src/rules/use_build_context_synchronously.dart:1293:11)
#21     _Visitor.visitMethodInvocation (package:linter/src/rules/use_build_context_synchronously.dart:1263:5)
#22     MethodInvocationImpl.accept (package:analyzer/src/dart/ast/ast.dart:11870:50)
#23     LinterVisitor._runSubscriptions (package:analyzer/src/lint/linter_visitor.dart:1096:14)
#24     LinterVisitor.visitMethodInvocation (package:analyzer/src/lint/linter_visitor.dart:644:5)
#25     MethodInvocationImpl.accept (package:analyzer/src/dart/ast/ast.dart:11870:50)
#26     MethodInvocationImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:11879:14)
#27     LinterVisitor.visitMethodInvocation (package:analyzer/src/lint/linter_visitor.dart:645:10)
#28     MethodInvocationImpl.accept (package:analyzer/src/dart/ast/ast.dart:11870:50)
#29     ExpressionStatementImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:6190:17)
#30     LinterVisitor.visitExpressionStatement (package:analyzer/src/lint/linter_visitor.dart:327:10)
#31     ExpressionStatementImpl.accept (package:analyzer/src/dart/ast/ast.dart:6186:50)
#32     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:12583:20)
#33     BlockImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:2091:17)
#34     LinterVisitor.visitBlock (package:analyzer/src/lint/linter_visitor.dart:111:10)
#35     BlockImpl.accept (package:analyzer/src/dart/ast/ast.dart:2087:50)
#36     BlockFunctionBodyImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:2047:12)
#37     LinterVisitor.visitBlockFunctionBody (package:analyzer/src/lint/linter_visitor.dart:117:10)
#38     BlockFunctionBodyImpl.accept (package:analyzer/src/dart/ast/ast.dart:2039:50)
#39     MethodDeclarationImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:11693:10)
#40     LinterVisitor.visitMethodDeclaration (package:analyzer/src/lint/linter_visitor.dart:639:10)
#41     MethodDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:11685:50)
#42     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:12583:20)
#43     ClassDeclarationImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:2954:13)
#44     LinterVisitor.visitClassDeclaration (package:analyzer/src/lint/linter_visitor.dart:165:10)
#45     ClassDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:2944:50)
#46     NodeListImpl.accept (package:analyzer/src/dart/ast/ast.dart:12583:20)
#47     CompilationUnitImpl.visitChildren (package:analyzer/src/dart/ast/ast.dart:3614:21)
#48     LinterVisitor.visitCompilationUnit (package:analyzer/src/lint/linter_visitor.dart:189:10)
#49     CompilationUnitImpl.accept (package:analyzer/src/dart/ast/ast.dart:3607:50)
#50     LibraryAnalyzer._computeLints (package:analyzer/src/dart/analysis/library_analyzer.dart:398:12)
#51     LibraryAnalyzer._computeDiagnostics (package:analyzer/src/dart/analysis/library_analyzer.dart:323:7)
#52     LibraryAnalyzer.analyze (package:analyzer/src/dart/analysis/library_analyzer.dart:108:5)
#53     AnalysisDriver._analyzeFileImpl.<anonymous closure> (package:analyzer/src/dart/analysis/driver.dart:1400:11)
<asynchronous suspension>
#54     PerformanceLog.runAsync (package:analyzer/src/dart/analysis/performance_logger.dart:50:14)
<asynchronous suspension>
#55     AnalysisDriver._analyzeFile.<anonymous closure> (package:analyzer/src/dart/analysis/driver.dart:1314:9)
<asynchronous suspension>
#56     OperationPerformanceImpl.runAsync (package:analyzer/src/util/performance/operation_performance.dart:174:14)
<asynchronous suspension>
#57     AnalysisDriver._analyzeFile (package:analyzer/src/dart/analysis/driver.dart:1311:5)
<asynchronous suspension>
#58     AnalysisDriver._getErrors (package:analyzer/src/dart/analysis/driver.dart:1745:5)
<asynchronous suspension>
#59     AnalysisDriver.performWork (package:analyzer/src/dart/analysis/driver.dart:1213:7)
<asynchronous suspension>
#60     AnalysisDriverScheduler._run (package:analyzer/src/dart/analysis/driver.dart:2455:7)
<asynchronous suspension>


null
Nothing to fix!

dart info

If providing this information as part of reporting a bug, please review the information
below to ensure it only contains things you're comfortable posting publicly.

#### General info

- Dart 3.5.3 (stable) (Wed Sep 11 16:22:47 2024 +0000) on "macos_arm64"
- on macos / Version 14.6.1 (Build 23G93)
- locale is en-DE

#### Project info

- sdk constraint: '>=3.5.3 <4.0.0'
- dependencies: badges, bloc, cached_network_image, characters, collection, confetti, connectivity_plus, cross_file, crypto, decimal, device_info_plus, diacritic, diffutil_dart, dio, dotted_border, dotted_line, drift, email_validator, equatable, facebook_app_events, fast_immutable_collections, firebase_analytics, firebase_auth, firebase_core, firebase_in_app_messaging, firebase_messaging, firebase_remote_config, fl_chart, flutter, flutter_animate, flutter_bloc, flutter_cache_manager, flutter_keyboard_visibility, flutter_launcher_icons, flutter_localizations, flutter_markdown, flutter_picker_plus, flutter_riverpod, flutter_staggered_grid_view, flutter_stream_listener, flutter_svg, freezed_annotation, go_router, google_sign_in, hive, hive_flutter, http, hydrated_bloc, image_picker, in_app_review, intl, json_annotation, keyboard_actions, logger, lottie, mime, mixpanel_flutter, package_info_plus, path, path_provider, path_to_regexp, percent_indicator, pin_code_fields, provider, purchases_flutter, responsive_framework, retry, riverpod_annotation, rxdart, sentry_flutter, share_plus, sign_in_with_apple, sliver_tools, sqlite3, sqlite3_flutter_libs, stream_channel, stream_transform, url_launcher, uuid, video_player, visibility_detector, wakelock_plus, webview_cookie_manager
- dev_dependencies: build_runner, custom_lint, drift_dev, file, flutter_lints, flutter_test, freezed, json_serializable, meta, patrol, patrol_finders, platform, riverpod_generator, riverpod_lint
- elided dependencies: 4

#### Process info

|   Memory |   CPU | Elapsed time | Command line                                                                               |
| -------: | ----: | -----------: | ------------------------------------------------------------------------------------------ |
|    13 MB |  0.0% |  04-03:56:32 | dart devtools --machine --allow-embedding --dtd-uri ws:<path>/zazJukNKK27qCbUq             |
|    59 MB |  0.0% |  04-03:56:35 | dart language-server --protocol=lsp --client-id=VS-Code --client-version=3.98.1            |
|    39 MB |  0.0% |        16:25 | dart lib/custom_lint_client.dart ::1 61258                                                 |
|    11 MB |  0.0% |  04-03:56:35 | dart tooling-daemon --machine                                                              |
|    26 MB |  0.0% |  04-03:56:35 | flutter_tools.snapshot daemon                                                              |
|    43 MB |  0.2% |        10:27 | flutter_tools.snapshot debug_adapter                                                       |
| 21409 MB | 89.0% |  06-01:20:24 | flutter_tools.snapshot debug_adapter                                                       |
|    54 MB |  1.2% |        10:26 | flutter_tools.snapshot run --machine --start-paused --dart-define-from-file .env.dev.json -d 00008020-0009682E2181002E --devtools-server-address http:<path>/ --target <path>/main.dart |

flutter --version
Flutter 3.24.3 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 2663184aa7 (6 weeks ago) • 2024-09-11 16:27:48 -0500
Engine • revision 36335019a8
Tools • Dart 3.5.3 • DevTools 2.37.3

[dart-github-bot]

Summary: The user encountered an error "Bad state: Missing a visit method for a node of type PatternAssignmentImpl" while running dart fix --dry-run. The error was not reproducible after running dart fix --apply.

[keertip]

@Yegair , thanks for the report. Do you have a list of fixes that were applied when dart fix --apply ran? What were the errors you were looking to fix?

[Yegair]

It did not fix any errors.

The reason I ran it was that I noted that VSCode stopped automatically adding const to constructors where possible on save, and I just wanted to know whether it was a VSCode or a Dart linter problem. It turned out that I was just missing a prefer_const_constructors: true in my analysis_options.yaml, which I assume was turned off by default in some recent update. However, I don't think this was related to the reported problem in any way.

[Yegair]

Just discovered that I can reproduce the issue by running the build_runner and then running dart fix --dry-run afterwards. To be more specific, I ran the following 3 commands:

$ flutter pub run build_runner clean
$ flutter pub run build_runner build --delete-conflicting-outputs
$ dart fix --dry-run

And again running dart fix a second time does not cause the same error (no matter if I use --dry-run or --apply)

[antonioaversa]

I have experienced the same issue, and made a minimal reproducer for the issue:

import 'package:flutter/src/widgets/framework.dart';

void use(BuildContext context) {}

patternDeclaration(bool b1, BuildContext context) {
  if (b1) {
    final (path, errorMsg) = ('', '');
  }

  use(context);
}

(String? path, String? errorMessage) f() {
  return ('', '');
}

The issue can be fixed by adding the following three overrides to the ExitDetector in analyzer\lib\src\dart\resolver\exit_detector.dart:

  @override
  bool visitPatternAssignment(PatternAssignment node) =>
      _nodeExits(node.expression);

  @override
  bool visitPatternVariableDeclaration(PatternVariableDeclaration node) =>
      _nodeExits(node.expression);

  @override
  bool visitPatternVariableDeclarationStatement(PatternVariableDeclarationStatement node) =>
      _nodeExits(node.declaration);

I will try to open a PR fixing the issues that ExitDetector has with pattern matching constructs.

[danielmessi13]

I have the same issue, but when i call dart analyze --fatal-infos