[messages] Use lower case diagnostic names in linter.

Changes the logic in `pkg/linter` to use
`DiagnosticCode.lowerCaseName` instead of `DiagnosticCode.name`, and
`DiagnosticCode.lowerCaseUniqueName` instead of
`DiagnosticCode.uniqueName`. This ensures that diagnostic codes are
matched in a case-insensitive fashion.

This paves the way for deprecating (and eventually removing) the
`DiagnosticCode.name` and `DiagnosticCode.uniqueName` getters.

Change-Id: I6a6a69645dc1b417c168a3d26ead9e76704ce0d2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/466131
Reviewed-by: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>

pkg/linter/lib/src/lint_codes.dart

@@ -17,9 +17,9 @@ class LinterLintCode extends LintCodeWithExpectedTypes {
   @override
   String get url {
     if (hasPublishedDocs) {
-      return 'https://dart.dev/diagnostics/$name';
+      return 'https://dart.dev/diagnostics/$lowerCaseName';
     }
-    return 'https://dart.dev/lints/$name';
+    return 'https://dart.dev/lints/$lowerCaseName';
   }
 }
 

pkg/linter/test/lint_code_test.dart

@@ -13,14 +13,16 @@ void main() {
       test('without published diagnostic docs', () {
         expect(
           _customCode.url,
-          equals('https://dart.dev/lints/${_customCode.name}'),
+          equals('https://dart.dev/lints/${_customCode.lowerCaseName}'),
         );
       });
 
       test('with published diagnostic docs', () {
         expect(
           _customCodeWithDocs.url,
-          equals('https://dart.dev/diagnostics/${_customCodeWithDocs.name}'),
+          equals(
+            'https://dart.dev/diagnostics/${_customCodeWithDocs.lowerCaseName}',
+          ),
         );
       });
     });

pkg/linter/test/rules/analyzer_public_api_test.dart

@@ -19,18 +19,18 @@ void main() {
 @reflectiveTest
 class AnalyzerPublicApiTest extends LintRuleTest {
   static String get badPartDirective =>
-      diag.analyzerPublicApiBadPartDirective.name;
+      diag.analyzerPublicApiBadPartDirective.lowerCaseName;
 
-  static String get badType => diag.analyzerPublicApiBadType.name;
+  static String get badType => diag.analyzerPublicApiBadType.lowerCaseName;
 
   static String get experimentalInconsistency =>
-      diag.analyzerPublicApiExperimentalInconsistency.name;
+      diag.analyzerPublicApiExperimentalInconsistency.lowerCaseName;
 
   static String get exportsNonPublicName =>
-      diag.analyzerPublicApiExportsNonPublicName.name;
+      diag.analyzerPublicApiExportsNonPublicName.lowerCaseName;
 
   static String get implInPublicApi =>
-      diag.analyzerPublicApiImplInPublicApi.name;
+      diag.analyzerPublicApiImplInPublicApi.lowerCaseName;
 
   String get libFile => '$testPackageRootPath/lib/file.dart';
 

pkg/linter/tool/machine.dart

@@ -70,7 +70,11 @@ Future<String> getMachineListing(
         'incompatible': rule.incompatibleRules,
         'sets': const [],
         'fixStatus':
-            fixStatusMap[rule.diagnosticCodes.first.uniqueName.suffix] ??
+            fixStatusMap[rule
+                .diagnosticCodes
+                .first
+                .lowerCaseUniqueName
+                .suffix] ??
             'unregistered',
         'details': info.deprecatedDetails,
         'sinceDartSdk': _versionToString(info.states.first.since),