Generate dart2js and analyzer files for shared messages.

pkg/dart_messages/bin/publish.dart

+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:convert';
+import 'dart:io';
+
+import '../lib/shared_messages.dart';
+
+const String jsonPath = '../lib/shared_messages.json';
+const String dart2jsPath =
+    '../../compiler/lib/src/diagnostics/generated/shared_messages.dart';
+const String analyzerPath =
+    '../../analyzer/lib/src/generated/generated/shared_messages.dart';
+
+const String dontEditWarning = '''
+/*
+DON'T EDIT. GENERATED. DON'T EDIT.

[Siggi Cherem (dart-lang), 2016/01/14 17:57:40]

I think it's ok to only say this once or twice :)

Consider adding here a note about how it is autogenerated, to guide someone who
discovers the generated file but doesn't know that's the next step.

[floitsch, 2016/01/15 17:20:38]

Done.

+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+DON'T EDIT. GENERATED. DON'T EDIT.
+*/''';
+
+const String copyrightHeader = '''
+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.''';
+
+void markAsReadonly(String path) {
+  // TODO(15078): mark as read-only. Currently not possible:
+  // http://dartbug.com/15078.
+}
+
+void emitJson() {
+  var input = MESSAGES;
+  var outPath = Platform.script.resolve(jsonPath).toFilePath();
+  print("Emitting JSON:");
+  print("  Input: ${input.length} entries");
+  print("  Output: $outPath");
+  new File(outPath).writeAsStringSync(messagesAsJson);
+  print("Emitting JSON done.");
+}
+
+String escapeString(String str) {
+  return JSON.encode(str);
+}
+
+/// Emits the messages in dart2js format.
+///
+/// The dart2js-format consists of two entities:
+///   1. the `MessageKind` enum, and
+///   2. the MessageKind-to-Template map `TEMPLATES`.
+///
+/// The template is an instance of MessageTemplate:
+///
+///     const MessageTemplate(
+///        this.kind,
+///        this.template,
+///        {this.howToFix,
+///         this.examples,
+///         this.options: const <String>[]});
+///
+/// A sample output thus looks as follows:
+///
+///     enum MessageKind {
+///       EXAMPLE_MESSAGE,
+///     }
+///
+///     const Map<MessageKind, MessageTemplate> {
+///       EXAMPLE_MESSAGE: const MessageTemplate(
+///         EXAMPLE_MESSAGE,
+///         "Don't use #foo with #bar",
+///         howToFix: "Just don't do it",
+///         options: const ['--some-flag']),
+///         examples: const ['''
+///     some example with bad code;'''],
+///     };
+void emitDart2js() {
+  var input = MESSAGES;
+  var outPath = Platform.script.resolve(dart2jsPath).toFilePath();
+  print("Emitting dart2js:");
+  print("  Input: ${input.length} entries");
+  print("  Output: $outPath");
+
+  var enumIds = input.keys.toList();
+
+  StringBuffer out = new StringBuffer();
+  out.writeln(dontEditWarning);
+  out.writeln(copyrightHeader);
+  out.writeln("import '../messages.dart' show MessageTemplate;");
+  out.writeln();
+  out.write(("enum SharedMessageKind {"));
+  // We generate on one line on purpose, so that users are less likely to
+  // modify the generated file.
+  out.write(enumIds.join(","));
+  out.writeln("}");
+  out.writeln();
+  out.writeln("const Map<SharedMessageKind, MessageTemplate> TEMPLATES = "
+      "const <SharedMessageKind, MessageTemplate>{ ");
+  input.forEach((name, message) {
+    out.write("SharedMessageKind.$name: const MessageTemplate(");

[Siggi Cherem (dart-lang), 2016/01/14 17:57:40]

indent the output here.

[floitsch, 2016/01/15 17:20:39]

Done.

+    // TODO(floitsch): include id.
+    out.write("SharedMessageKind.$name, ");
+    out.write(escapeString(message.template));
+    if (message.howToFix != null) {
+      out.write(", howToFix: ${escapeString(message.howToFix)}");

[Siggi Cherem (dart-lang), 2016/01/14 17:57:40]

split each name argument to a separate line (and indent)

[floitsch, 2016/01/15 17:20:39]

Done.

+    }
+    if (message.options != null) {
+      out.write(", options: const [");
+      out.write(message.options.map(escapeString).join(","));
+      out.write("]");
+    }
+    if (message.examples != null) {
+      out.write(", examples: const [");
+      for (var example in message.examples) {
+        if (example is String) {
+          out.write(escapeString(example));

[Siggi Cherem (dart-lang), 2016/01/14 17:57:40]

maybe switch to use escapeString for ''' here and below? I think we can also
indent the contents, since these strings are used for automated testing and not
to present messages to users.

Basically all the suggestions above are about making the generated code more
readable. For example:

Instead of:

const Map<SharedMessageKind, MessageTemplate> TEMPLATES = const
<SharedMessageKind, MessageTemplate>{
SharedMessageKind.exampleMessage: const MessageTemplate(SharedMessageKind.exampl
eMessage, "#use #named #arguments", howToFix: "an explanation on how to fix thin
gs", examples: const ["Some multiline example;\nThat generates the bug.",const {
'fileA.dart':"or a map from file to content.\nagain multiline",'fileB.dart':"wit
h possibly multiple files.\nmuliline too",},]),

We can generate:

const Map<SharedMessageKind, MessageTemplate> TEMPLATES =
    const <SharedMessageKind, MessageTemplate>{
  SharedMessageKind.exampleMessage: const MessageTemplate(
      SharedMessageKind.exampleMessage,
      "#use #named #arguments",
      howToFix: "an explanation on how to fix things",
      examples: const ['''
          Some multiline example;
          That generates the bug.''',
      const {
        'fileA.dart': '''
            or a map from file to content.
            again multiline
            ''',
        'fileB.dart':'''
            with possibly multiple files.
            muliline too
            ''',
       },
  ]),
  ...

[floitsch, 2016/01/15 17:20:39]

Done.

+        } else if (example is Map) {
+          out.write("const {");
+          example.forEach((String fileName, String content) {
+            out.write("'$fileName':");
+            out.write(escapeString(content));
+            out.write(",");
+          });
+          out.write("}");
+        }
+        out.write(",");
+      }
+      out.write("]");
+    }
+    out.writeln("),");
+  });
+  out.writeln("};");
+
+  new File(outPath).writeAsStringSync(out.toString());
+  print("Emitting dart2js done.");
+}
+
+/// Translates the shared messages in `../lib/shared_messages.dart` to JSON,
+/// dart2js, and analyzer formats.
+///
+/// Emits the json-output to [jsonPath], the dart2js-output to [dart2jsPath],
+/// and the analyzer-output to [analyzerPath].
+void main() {
+  emitJson();
+  emitDart2js();
+  // TODO(floitsch): emit analyzer.
+}