Run dartfmt on generated file.

pkg/front_end/tool/_fasta/generate_messages.dart

Index: pkg/front_end/tool/_fasta/generate_messages.dart
diff --git a/pkg/front_end/tool/_fasta/generate_messages.dart b/pkg/front_end/tool/_fasta/generate_messages.dart
index 9c62894d42d5cc164dba6ad98ac3f16d4b420e4c..656cc043f6a8a648f8d8af95ee4227e01b9756ad 100644
--- a/pkg/front_end/tool/_fasta/generate_messages.dart
+++ b/pkg/front_end/tool/_fasta/generate_messages.dart
@@ -10,6 +10,8 @@ import 'package:yaml/yaml.dart' show loadYaml;
 
 import 'package:front_end/src/fasta/parser/error_kind.dart' show ErrorKind;
 
+import 'package:dart_style/dart_style.dart' show DartFormatter;

[Siggi Cherem (dart-lang), 2017/07/12 20:06:51]

note: this introduced a circular dependency on fasta_codes_generated.dart
(package:dart_style imports  package:analyzer which in turn imports
package:front_end including the generated file.)

As a result, if the file is missing or broken this script fails to run. I run
into this because of a merge conflict and wanted to regenerate the file without
bothering to revert it to a valid Dart file.

I suggest we run the formatter as a separate process instead.

[ahe, 2017/07/13 00:26:54]

We could do that, but then we have to use the slightly outdated version that's
stored somewhere in tools/. That's also a source of confusion.

What I've been doing is this:

git checkout current_branch_name --
pkg/front_end/lib/src/fasta/fasta_codes_generated.dart

Is that an acceptable workaround for you?

+
 main(List<String> arguments) async {
   var port = new ReceivePort();
   Uri messagesFile = Platform.script.resolve("../../messages.yaml");
@@ -52,9 +54,12 @@ import 'package:front_end/src/fasta/parser/error_kind.dart' show ErrorKind;
     sb.writeln(compileTemplate(name, map['template'], map['tip']));
   });
 
+  String dartfmtedText = new DartFormatter().format("$sb");
+
   Uri problemsFile = await Isolate.resolvePackageUri(
       Uri.parse('package:front_end/src/fasta/problems.dart'));
-  await new File.fromUri(problemsFile).writeAsString("$sb", flush: true);
+  await new File.fromUri(problemsFile)
+      .writeAsString(dartfmtedText, flush: true);
   port.close();
 }