[messages] Prepare to standardize DiagnosticCode names to all lower case.

In a follow-up CL, I will change the code generator for diagnostic
messages so that all code-generated instances of `DiagnosticCode` have
`name` and `uniqueName` fields in all lower case letters. This will
help pave the way toward resolving conflicts between the diagnostic
code naming conventions between the analyzer and CFE.

To prepare for this change, the following pieces of code need to first
be modified to be case insensitive:

- The `_ignoreNullSafetyWarnings` check in
  `RemoveDeadCodeSoundFlowAnalysisTest`.

- The `_diagnosticCodes` fields in `_CannotIgnoreOptionValidator` and
  `_ErrorFilterOptionValidator`.

- The `computeErrorData` methods in `ConstantsDataComputer` and
  `_InheritanceDataComputer`.

- The `_writeDiagnostic` methods in `DriverEventsPrinter` and
  `ResolvedUnitResultPrinter`.

- The `_validateMessages` and `_validateSnippet` methods in
  `DocumentationValidator`.

- The `run` method in `TextualOutline`.

In most cases, the code was changed to be case insensitive by having
it call `.toLowerCase()` or `.toUpperCase()` on the diagnostic code
name before operating on it. In one case I was able to re-use the
`AnalyzerCode.lowerSnakeCaseName` getter.

Change-Id: I6a6a6964f3cc4c71f2e82478855d64d5ef91d26b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/465804
Reviewed-by: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Paul Berry <[email protected]>

Author: stereotype441

pkg/analysis_server/test/src/services/correction/fix/remove_dead_code_test.dart

@@ -1159,8 +1159,8 @@ void f(int i, int j) => i;
   /// Error filter ignoring warnings that frequently occur in conjunction with
   /// code that is dead due to sound flow analysis.
   bool _ignoreNullSafetyWarnings(Diagnostic diagnostic) => !const {
-    'DEAD_NULL_AWARE_EXPRESSION',
-    'INVALID_NULL_AWARE_OPERATOR',
-    'UNNECESSARY_NULL_COMPARISON',
-  }.contains(diagnostic.diagnosticCode.name);
+    'dead_null_aware_expression',
+    'invalid_null_aware_operator',
+    'unnecessary_null_comparison',
+  }.contains(diagnostic.diagnosticCode.name.toLowerCase());
 }

pkg/analyzer/lib/src/analysis_options/options_file_validator.dart

@@ -346,7 +346,7 @@ class _AnalyzerTopLevelOptionsValidator extends _TopLevelOptionValidator {
 class _CannotIgnoreOptionValidator extends OptionsValidator {
   /// Lazily populated set of diagnostic code names.
   static final Set<String> _diagnosticCodes = diagnosticCodeValues
-      .map((DiagnosticCode code) => code.name)
+      .map((DiagnosticCode code) => code.name.toUpperCase())
       .toSet();
 
   /// The diagnostic code names that existed, but were removed.
@@ -591,7 +591,7 @@ class _ErrorFilterOptionValidator extends OptionsValidator {
 
   /// Lazily populated set of diagnostic code names.
   static final Set<String> _diagnosticCodes = diagnosticCodeValues
-      .map((DiagnosticCode code) => code.name)
+      .map((DiagnosticCode code) => code.name.toUpperCase())
       .toSet();
 
   /// The diagnostic code names that existed, but were removed.

pkg/analyzer/test/id_tests/constant_test.dart

@@ -60,7 +60,9 @@ class ConstantsDataComputer extends DataComputer<String> {
     var diagnosticCodes = diagnostics
         .map((e) => e.diagnosticCode)
         .where((c) => c != diag.constInitializedWithNonConstantValue);
-    return diagnosticCodes.isNotEmpty ? diagnosticCodes.join(',') : null;
+    return diagnosticCodes.isNotEmpty
+        ? diagnosticCodes.map((c) => c.uniqueName.toUpperCase()).join(',')
+        : null;
   }
 
   @override

pkg/analyzer/test/id_tests/inheritance_test.dart

@@ -65,7 +65,9 @@ class _InheritanceDataComputer extends DataComputer<String> {
     Id id,
     List<Diagnostic> diagnostics,
   ) {
-    return diagnostics.map((e) => e.diagnosticCode).join(',');
+    return diagnostics
+        .map((e) => e.diagnosticCode.uniqueName.toUpperCase())
+        .join(',');
   }
 
   @override

pkg/analyzer/test/src/dart/analysis/result_printer.dart

@@ -409,7 +409,9 @@ class DriverEventsPrinter {
   }
 
   void _writeDiagnostic(Diagnostic d) {
-    sink.writelnWithIndent('${d.offset} +${d.length} ${d.diagnosticCode.name}');
+    sink.writelnWithIndent(
+      '${d.offset} +${d.length} ${d.diagnosticCode.name.toUpperCase()}',
+    );
   }
 
   void _writeErrorsEvent(GetErrorsEvent event) {
@@ -1965,7 +1967,9 @@ class ResolvedUnitResultPrinter {
   }
 
   void _writeDiagnostic(Diagnostic d) {
-    sink.writelnWithIndent('${d.offset} +${d.length} ${d.diagnosticCode.name}');
+    sink.writelnWithIndent(
+      '${d.offset} +${d.length} ${d.diagnosticCode.name.toUpperCase()}',
+    );
   }
 
   void _writeResolvedUnitResult(ResolvedUnitResultImpl result) {

pkg/analyzer/test/verify_diagnostics_test.dart

@@ -374,7 +374,8 @@ class DocumentationValidator {
         message.documentation,
       );
       if (docs != null) {
-        codeName = (message.sharedName ?? message.analyzerCode).snakeCaseName;
+        codeName =
+            (message.sharedName ?? message.analyzerCode).lowerSnakeCaseName;
         variableName = message.analyzerCode.lowerSnakeCaseName;
         if (unverifiedDocs.contains(variableName)) {
           continue;
@@ -443,7 +444,7 @@ class DocumentationValidator {
         _reportProblem('Expected one error but found none ($section $index).');
       } else if (errorCount == 1) {
         Diagnostic diagnostic = diagnostics[0];
-        if (diagnostic.diagnosticCode.name != codeName) {
+        if (diagnostic.diagnosticCode.name.toLowerCase() != codeName) {
           _reportProblem(
             'Expected an error with code $codeName, '
             'found ${diagnostic.diagnosticCode} ($section $index).',

pkg/front_end/test/textual_outline_suite.dart

@@ -170,7 +170,8 @@ class TextualOutline extends Step<TestDescription, TestDescription, Context> {
           formatterExceptionSt = st;
           if (e is FormatterException) {
             for (var error in e.errors) {
-              if (error.diagnosticCode.name == "EXPERIMENT_NOT_ENABLED") {
+              if (error.diagnosticCode.name.toUpperCase() ==
+                  "EXPERIMENT_NOT_ENABLED") {
                 allowFormatterCrash = true;
               }
             }