Dart format cannot format file with extension type in it

[srawlins]

I get this when using dart format with a dart compiled from HEAD today:

$ xcodebuild/ReleaseX64/dart-sdk/bin/dart format --enable-experiment=inline-class pkg/analysis_server/test/verify_error_fix_status_test2.dart
Hit a bug in the formatter when formatting pkg/analysis_server/test/verify_error_fix_status_test2.dart.
Please report at github.com/dart-lang/dart_style/issues.
Exception: Missing implementation of visitExtensionTypeDeclaration
#0      ThrowingAstVisitor._throw (package:analyzer/dart/ast/visitor.dart:2911:5)
#1      ThrowingAstVisitor.visitExtensionTypeDeclaration (package:analyzer/dart/ast/visitor.dart:2526:7)
#2      ExtensionTypeDeclarationImpl.accept (package:analyzer/src/dart/ast/ast.dart:6847:20)
#3      SourceVisitor.visit (package:dart_style/src/source_visitor.dart:3099:10)
#4      SourceVisitor.visitCompilationUnit (package:dart_style/src/source_visitor.dart:668:7)
#5      CompilationUnitImpl.accept (package:analyzer/src/dart/ast/ast.dart:3650:50)
#6      SourceVisitor.visit (package:dart_style/src/source_visitor.dart:3099:10)
#7      SourceVisitor.run (package:dart_style/src/source_visitor.dart:120:5)
#8      DartFormatter.formatSource (package:dart_style/src/dart_formatter.dart:179:26)
#9      processFile (package:dart_style/src/io.dart:147:28)
#10     formatPaths (package:dart_style/src/io.dart:73:12)
#11     FormatCommand.run (package:dart_style/src/cli/format_command.dart:156:7)
#12     CommandRunner.runCommand (package:args/command_runner.dart:212:27)
#13     DartdevRunner.runCommand (package:dartdev/dartdev.dart:240:30)
#14     CommandRunner.run.<anonymous closure> (package:args/command_runner.dart:122:25)
#15     new Future.sync (dart:async/future.dart:305:31)
#16     CommandRunner.run (package:args/command_runner.dart:122:14)
#17     runDartdev (package:dartdev/dartdev.dart:59:29)
#18     main (file:///Users/srawlins/code/dart-sdk/sdk/pkg/dartdev/bin/dartdev.dart:11:9)
#19     _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:293:33)
#20     _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:184:12)

Formatted no files in 0.10 seconds.

The file in question is:

import 'package:yaml/yaml.dart';

  extension   type   _StatusInfo(YamlMap documentNode) {
}

[lrhn]

That's tracked here: dart-lang/dart_style#1129