[messages] Make utility to convert to camelCase.

Adds a temporary utility, `switch_to_camel_case.dart`, that will
switch the `messages.yaml` files to using `camelCase` for message
keys, `sharedName` fields, and `analyzerCode` fields.

In follow-up CLs, I will run the script and then remove it. This will
eliminate a significant inconsistency between the diagnostic code
formats in the analyzer and the front end.

Change-Id: I6a6a69645d4342abceb8f51d2e2e1d065ebef8d3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/466560
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Paul Berry <[email protected]>

Author: stereotype441

pkg/analyzer_utilities/pubspec.yaml

@@ -21,5 +21,6 @@ dependencies:
 
 # Use 'any' constraints here; we get our versions from the DEPS file.
 dev_dependencies:
+  analyzer_plugin: any
   lints: any
   test_reflective_loader: any

pkg/analyzer_utilities/tool/messages/switch_to_camel_case.dart

@@ -0,0 +1,88 @@
+// Copyright (c) 2025, 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.
+
+/// This is a temporary utility script that modifies error codes in
+/// `messages.yaml` files, changing analyzer error codes from UPPER_SNAKE_CASE
+/// to camelCase.
+library;
+
+import 'dart:io';
+
+import 'package:analyzer_plugin/protocol/protocol_common.dart';
+import 'package:analyzer_utilities/analyzer_messages.dart';
+import 'package:analyzer_utilities/extensions/string.dart';
+import 'package:analyzer_utilities/lint_messages.dart';
+import 'package:analyzer_utilities/messages.dart';
+import 'package:collection/collection.dart';
+import 'package:source_span/source_span.dart';
+import 'package:yaml/yaml.dart';
+
+void main() {
+  Map<Uri, Converter> converters = {};
+  for (var message in [
+    ...analyzerMessages,
+    ...analysisServerMessages,
+    ...feAnalyzerSharedMessages,
+    ...lintMessages,
+    ...frontEndMessages,
+  ]) {
+    var sourceUrl = message.keySpan.sourceUrl;
+    (converters[sourceUrl!] ??= Converter(
+      File(sourceUrl.toFilePath()),
+    )).convertMessage(message);
+  }
+  for (var converter in converters.values) {
+    converter.apply();
+  }
+}
+
+class Converter {
+  final File file;
+  late final isAnalyzerFormat = switch (Uri.file(file.path).pathSegments) {
+    [..., '_fe_analyzer_shared', 'messages.yaml'] => false,
+    [..., 'analyzer', 'messages.yaml'] => true,
+    [..., 'analysis_server', 'messages.yaml'] => true,
+    [..., 'linter', 'messages.yaml'] => true,
+    _ => throw 'Unexpected path ${file.path}',
+  };
+  late final String content = file.readAsStringSync();
+  late final yaml = loadYamlNode(content) as YamlMap;
+  late final messageMaps = isAnalyzerFormat ? yaml.nodes.values : [yaml];
+  late final Map<String, YamlMap> messageNodesByName = {
+    for (var messageMap in messageMaps)
+      for (var MapEntry(:key, :value) in (messageMap as YamlMap).nodes.entries)
+        (key as YamlScalar).value as String: value as YamlMap,
+  };
+  final List<SourceEdit> edits = [];
+
+  Converter(this.file);
+
+  void apply() {
+    edits.sortBy((e) => -e.offset);
+    file.writeAsStringSync(SourceEdit.applySequence(content, edits));
+  }
+
+  void convertMessage(Message message) {
+    if (message is AnalyzerMessage && !message.keyString.isCamelCase) {
+      _edit(message.keySpan, message.keyString.toCamelCase());
+    } else if (message is CfeStyleMessage) {
+      _edit(message.keySpan, message.keyString.toSnakeCase().toCamelCase());
+    }
+    if (message is SharedMessage) {
+      var messageNode = yaml.nodes[message.keyString] as YamlMap;
+      _edit(
+        messageNode.nodes['analyzerCode']!.span,
+        message.analyzerCode.camelCaseName,
+      );
+    }
+    if (message.sharedName case var sharedName?) {
+      var messageNode = messageNodesByName[message.keyString] as YamlMap;
+      _edit(messageNode.nodes['sharedName']!.span, sharedName.camelCaseName);
+    }
+  }
+
+  void _edit(SourceSpan span, String newText) {
+    edits.add(SourceEdit(span.start.offset, span.length, newText));
+  }
+}