Record elements and types parts of missing patterns for AddMissingSwitchCases fix.

Bug: https://github.com/dart-lang/sdk/issues/51985
Change-Id: I48e04e992ccab5cb5dedb5df328ba13ffcf6b560
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/302200
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analysis_server/lib/src/services/correction/dart/add_missing_switch_cases.dart

@@ -5,7 +5,10 @@
 import 'package:analysis_server/src/services/correction/dart/abstract_producer.dart';
 import 'package:analysis_server/src/services/correction/fix.dart';
 import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/error/error.dart';
+import 'package:analyzer/src/generated/exhaustiveness.dart';
 import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
+import 'package:analyzer_plugin/utilities/change_builder/change_builder_dart.dart';
 import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
 
 class AddMissingSwitchCases extends CorrectionProducer {
@@ -22,8 +25,13 @@ class AddMissingSwitchCases extends CorrectionProducer {
   Future<void> compute(ChangeBuilder builder) async {
     final node = this.node;
 
-    final patternCode = _patternSuggestion();
-    if (patternCode == null) {
+    final diagnostic = this.diagnostic;
+    if (diagnostic is! AnalysisError) {
+      return;
+    }
+
+    final patternParts = diagnostic.data;
+    if (patternParts is! List<MissingPatternPart>) {
       return;
     }
 
@@ -31,7 +39,7 @@ class AddMissingSwitchCases extends CorrectionProducer {
       await _switchExpression(
         builder: builder,
         node: node,
-        patternCode: patternCode,
+        patternParts: patternParts,
       );
     }
 
@@ -39,38 +47,15 @@ class AddMissingSwitchCases extends CorrectionProducer {
       await _switchStatement(
         builder: builder,
         node: node,
-        patternCode: patternCode,
+        patternParts: patternParts,
       );
     }
   }
 
-  /// Extracts the pattern code suggestion from the correction message.
-  ///
-  /// TODO(scheglov) In general, this code might be not always valid code.
-  String? _patternSuggestion() {
-    final diagnostic = this.diagnostic;
-    if (diagnostic == null) {
-      return null;
-    }
-
-    final correctionMessage = diagnostic.correctionMessage;
-    if (correctionMessage == null) {
-      return null;
-    }
-
-    final regExp = RegExp("that match '(.+)'");
-    final match = regExp.firstMatch(correctionMessage);
-    if (match == null) {
-      return null;
-    }
-
-    return match.group(1);
-  }
-
   Future<void> _switchExpression({
     required ChangeBuilder builder,
     required SwitchExpression node,
-    required String patternCode,
+    required List<MissingPatternPart> patternParts,
   }) async {
     final lineIndent = utils.getLinePrefix(node.offset);
     final singleIndent = utils.getIndent(1);
@@ -88,7 +73,7 @@ class AddMissingSwitchCases extends CorrectionProducer {
         builder.writeln('// TODO: Handle this case.');
         builder.write(lineIndent);
         builder.write(singleIndent);
-        builder.write(patternCode);
+        _writePatternParts(builder, patternParts);
         builder.writeln(' => null,');
         builder.write(location.suffix);
       });
@@ -98,7 +83,7 @@ class AddMissingSwitchCases extends CorrectionProducer {
   Future<void> _switchStatement({
     required ChangeBuilder builder,
     required SwitchStatement node,
-    required String patternCode,
+    required List<MissingPatternPart> patternParts,
   }) async {
     final lineIndent = utils.getLinePrefix(node.offset);
     final singleIndent = utils.getIndent(1);
@@ -114,7 +99,7 @@ class AddMissingSwitchCases extends CorrectionProducer {
         builder.write(lineIndent);
         builder.write(singleIndent);
         builder.write('case ');
-        builder.write(patternCode);
+        _writePatternParts(builder, patternParts);
         builder.writeln(':');
         builder.write(lineIndent);
         builder.write(singleIndent);
@@ -124,4 +109,21 @@ class AddMissingSwitchCases extends CorrectionProducer {
       });
     });
   }
+
+  void _writePatternParts(
+    DartEditBuilder builder,
+    List<MissingPatternPart> parts,
+  ) {
+    for (final part in parts) {
+      if (part is MissingPatternEnumValuePart) {
+        builder.writeReference(part.enumElement);
+        builder.write('.');
+        builder.write(part.value.name);
+      } else if (part is MissingPatternTextPart) {
+        builder.write(part.text);
+      } else if (part is MissingPatternTypePart) {
+        builder.writeType(part.type);
+      }
+    }
+  }
 }

pkg/analysis_server/test/protocol_server_test.dart

@@ -347,6 +347,9 @@ class MockAnalysisError implements engine.AnalysisError {
   @override
   String? get correctionMessage => _correctionMessage;
 
+  @override
+  Object? get data => throw UnimplementedError();
+
   @override
   engine.ErrorCode get errorCode => _errorCode!;
 

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

@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analysis_server/src/services/correction/fix.dart';
+import 'package:analysis_server/src/services/linter/lint_names.dart';
 import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -10,16 +11,55 @@ import 'fix_processor.dart';
 
 void main() {
   defineReflectiveSuite(() {
-    defineReflectiveTests(AddMissingSwitchCasesTest);
+    defineReflectiveTests(AddMissingSwitchCasesTest_SwitchExpression);
+    defineReflectiveTests(AddMissingSwitchCasesTest_SwitchStatement);
   });
 }
 
 @reflectiveTest
-class AddMissingSwitchCasesTest extends FixProcessorTest {
+class AddMissingSwitchCasesTest_SwitchExpression extends FixProcessorTest {
   @override
   FixKind get kind => DartFixKind.ADD_MISSING_SWITCH_CASES;
 
-  Future<void> test_switchExpression_enum_hasFirst() async {
+  Future<void> test_bool_hasFalse() async {
+    await resolveTestCode('''
+int f(bool x) {
+  return switch (x) {
+    false => 0,
+  };
+}
+''');
+    await assertHasFix('''
+int f(bool x) {
+  return switch (x) {
+    false => 0,
+    // TODO: Handle this case.
+    true => null,
+  };
+}
+''');
+  }
+
+  Future<void> test_bool_hasTrue() async {
+    await resolveTestCode('''
+int f(bool x) {
+  return switch (x) {
+    true => 0,
+  };
+}
+''');
+    await assertHasFix('''
+int f(bool x) {
+  return switch (x) {
+    true => 0,
+    // TODO: Handle this case.
+    false => null,
+  };
+}
+''');
+  }
+
+  Future<void> test_enum_hasFirst() async {
     await resolveTestCode('''
 enum E {
   first, second, third
@@ -46,7 +86,74 @@ int f(E x) {
 ''');
   }
 
-  Future<void> test_switchExpression_num_anyDouble_intProperty() async {
+  Future<void> test_enum_importedWithPrefix() async {
+    newFile('$testPackageLibPath/a.dart', r'''
+enum E {
+  first, second, third
+}
+''');
+
+    await resolveTestCode('''
+import 'a.dart' as prefix;
+
+int f(prefix.E x) {
+  return switch (x) {
+  };
+}
+''');
+    await assertHasFix('''
+import 'a.dart' as prefix;
+
+int f(prefix.E x) {
+  return switch (x) {
+    // TODO: Handle this case.
+    prefix.E.first => null,
+  };
+}
+''');
+  }
+
+  Future<void> test_enum_notImported() async {
+    newFile('$testPackageLibPath/a.dart', r'''
+enum E {
+  first, second, third
+}
+''');
+
+    newFile('$testPackageLibPath/b.dart', r'''
+import 'a.dart';
+
+var value = E.first;
+''');
+
+    createAnalysisOptionsFile(
+      lints: [
+        LintNames.prefer_relative_imports,
+      ],
+    );
+
+    await resolveTestCode('''
+import 'b.dart';
+
+int f() {
+  return switch (value) {
+  };
+}
+''');
+    await assertHasFix('''
+import 'a.dart';
+import 'b.dart';
+
+int f() {
+  return switch (value) {
+    // TODO: Handle this case.
+    E.first => null,
+  };
+}
+''');
+  }
+
+  Future<void> test_num_anyDouble_intProperty() async {
     await resolveTestCode('''
 int f(num x) {
   return switch (x) {
@@ -67,7 +174,7 @@ int f(num x) {
 ''');
   }
 
-  Future<void> test_switchExpression_num_doubleAny() async {
+  Future<void> test_num_doubleAny() async {
     await resolveTestCode('''
 int f(num x) {
   return switch (x) {
@@ -86,7 +193,30 @@ int f(num x) {
 ''');
   }
 
-  Future<void> test_switchExpression_num_doubleAny_intWhen() async {
+  Future<void> test_num_doubleAny_coreWithPrefix() async {
+    await resolveTestCode('''
+import 'dart:core' as core;
+
+core.int f(core.num x) {
+  return switch (x) {
+    core.double() => 0,
+  };
+}
+''');
+    await assertHasFix('''
+import 'dart:core' as core;
+
+core.int f(core.num x) {
+  return switch (x) {
+    core.double() => 0,
+    // TODO: Handle this case.
+    core.int() => null,
+  };
+}
+''');
+  }
+
+  Future<void> test_num_doubleAny_intWhen() async {
     await resolveTestCode('''
 int f(num x) {
   return switch (x) {
@@ -107,7 +237,7 @@ int f(num x) {
 ''');
   }
 
-  Future<void> test_switchExpression_num_empty() async {
+  Future<void> test_num_empty() async {
     await resolveTestCode('''
 int f(num x) {
   return switch (x) {};
@@ -122,8 +252,14 @@ int f(num x) {
 }
 ''');
   }
+}
 
-  Future<void> test_switchStatement_num_doubleAny() async {
+@reflectiveTest
+class AddMissingSwitchCasesTest_SwitchStatement extends FixProcessorTest {
+  @override
+  FixKind get kind => DartFixKind.ADD_MISSING_SWITCH_CASES;
+
+  Future<void> test_num_doubleAny() async {
     await resolveTestCode('''
 void f(num x) {
   switch (x) {
@@ -144,7 +280,7 @@ void f(num x) {
 ''');
   }
 
-  Future<void> test_switchStatement_num_doubleAny_intProperty() async {
+  Future<void> test_num_doubleAny_intProperty() async {
     await resolveTestCode('''
 void f(num x) {
   switch (x) {
@@ -169,7 +305,7 @@ void f(num x) {
 ''');
   }
 
-  Future<void> test_switchStatement_num_empty() async {
+  Future<void> test_num_empty() async {
     await resolveTestCode('''
 void f(num x) {
   switch (x) {}

pkg/analyzer/lib/error/error.dart

@@ -84,6 +84,9 @@ class AnalysisError implements Diagnostic {
   /// if there are no context messages.
   final List<DiagnosticMessage> _contextMessages;
 
+  /// Data associated with this error, specific for [errorCode].
+  final Object? data;
+
   /// The correction to be displayed for this error, or `null` if there is no
   /// correction information for this error.
   String? _correctionMessage;
@@ -104,6 +107,7 @@ class AnalysisError implements Diagnostic {
     ErrorCode errorCode, [
     List<Object?>? arguments,
     List<DiagnosticMessage> contextMessages = const [],
+    Object? data,
   ]) {
     return AnalysisError.tmp(
       source: source,
@@ -112,6 +116,7 @@ class AnalysisError implements Diagnostic {
       errorCode: errorCode,
       arguments: arguments ?? const [],
       contextMessages: contextMessages,
+      data: data,
     );
   }
 
@@ -124,6 +129,7 @@ class AnalysisError implements Diagnostic {
     required String message,
     String? correctionMessage,
     List<DiagnosticMessage> contextMessages = const [],
+    this.data,
   })  : _correctionMessage = correctionMessage,
         _contextMessages = contextMessages {
     _problemMessage = DiagnosticMessageImpl(
@@ -147,6 +153,7 @@ class AnalysisError implements Diagnostic {
     required this.errorCode,
     List<Object?> arguments = const [],
     List<DiagnosticMessage> contextMessages = const [],
+    this.data,
   }) : _contextMessages = contextMessages {
     assert(
       arguments.length == errorCode.numParameters,

pkg/analyzer/lib/error/listener.dart

@@ -97,16 +97,27 @@ class ErrorReporter {
 
   /// Report an error with the given [errorCode] and [arguments].
   /// The [node] is used to compute the location of the error.
-  void reportErrorForNode(ErrorCode errorCode, AstNode node,
-      [List<Object>? arguments, List<DiagnosticMessage>? messages]) {
+  void reportErrorForNode(
+    ErrorCode errorCode,
+    AstNode node, [
+    List<Object>? arguments,
+    List<DiagnosticMessage>? messages,
+    Object? data,
+  ]) {
     reportErrorForOffset(
-        errorCode, node.offset, node.length, arguments, messages);
+        errorCode, node.offset, node.length, arguments, messages, data);
   }
 
   /// Report an error with the given [errorCode] and [arguments]. The location
   /// of the error is specified by the given [offset] and [length].
-  void reportErrorForOffset(ErrorCode errorCode, int offset, int length,
-      [List<Object>? arguments, List<DiagnosticMessage>? messages]) {
+  void reportErrorForOffset(
+    ErrorCode errorCode,
+    int offset,
+    int length, [
+    List<Object>? arguments,
+    List<DiagnosticMessage>? messages,
+    Object? data,
+  ]) {
     if (lockLevel != 0) {
       return;
     }
@@ -122,6 +133,7 @@ class ErrorReporter {
         errorCode: errorCode,
         arguments: arguments ?? const [],
         contextMessages: messages,
+        data: data,
       ),
     );
   }
@@ -135,10 +147,15 @@ class ErrorReporter {
 
   /// Report an error with the given [errorCode] and [arguments]. The [token] is
   /// used to compute the location of the error.
-  void reportErrorForToken(ErrorCode errorCode, Token token,
-      [List<Object>? arguments, List<DiagnosticMessage>? messages]) {
+  void reportErrorForToken(
+    ErrorCode errorCode,
+    Token token, [
+    List<Object>? arguments,
+    List<DiagnosticMessage>? messages,
+    Object? data,
+  ]) {
     reportErrorForOffset(
-        errorCode, token.offset, token.length, arguments, messages);
+        errorCode, token.offset, token.length, arguments, messages, data);
   }
 
   /// Report an error with the given [errorCode] and [arguments]. The [node] is

pkg/analyzer/lib/src/dart/analysis/driver.dart

@@ -1346,8 +1346,8 @@ class AnalysisDriver implements AnalysisDriverGeneric {
           testingData: testingData,
         ).analyze();
 
+        late UnitAnalysisResult fileResult;
         late Uint8List bytes;
-        late CompilationUnit resolvedUnit;
         for (var unitResult in results) {
           var unitBytes =
               _serializeResolvedUnit(unitResult.unit, unitResult.errors);
@@ -1356,16 +1356,21 @@ class AnalysisDriver implements AnalysisDriverGeneric {
           String unitKey = _getResolvedUnitKey(unitSignature);
           _byteStore.putGet(unitKey, unitBytes);
           if (unitResult.file == file) {
+            fileResult = unitResult;
             bytes = unitBytes;
-            resolvedUnit = unitResult.unit;
           }
         }
 
         // Return the result, full or partial.
         _logger.writeln('Computed new analysis result.');
-        var result = _getAnalysisResultFromBytes(file, signature, bytes,
-            content: withUnit ? file.content : null,
-            resolvedUnit: withUnit ? resolvedUnit : null);
+        var result = _getAnalysisResultFromBytes(
+          file,
+          signature,
+          bytes,
+          content: withUnit ? file.content : null,
+          resolvedUnit: withUnit ? fileResult.unit : null,
+          errors: fileResult.errors,
+        );
         if (withUnit && _priorityFiles.contains(path)) {
           _priorityResults[path] = result.unitResult!;
         }
@@ -1588,10 +1593,15 @@ class AnalysisDriver implements AnalysisDriverGeneric {
   /// Load the [AnalysisResult] for the given [file] from the [bytes]. Set
   /// optional [content] and [resolvedUnit].
   AnalysisResult _getAnalysisResultFromBytes(
-      FileState file, String signature, Uint8List bytes,
-      {String? content, CompilationUnit? resolvedUnit}) {
+    FileState file,
+    String signature,
+    Uint8List bytes, {
+    String? content,
+    CompilationUnit? resolvedUnit,
+    List<AnalysisError>? errors,
+  }) {
     var unit = AnalysisDriverResolvedUnit.fromBuffer(bytes);
-    List<AnalysisError> errors = _getErrorsFromSerialized(file, unit.errors);
+    errors ??= _getErrorsFromSerialized(file, unit.errors);
     _updateHasErrorOrWarningFlag(file, errors);
     var index = unit.index!;
     if (content != null && resolvedUnit != null) {

pkg/analyzer/lib/src/dart/constant/constant_verifier.dart

@@ -840,19 +840,24 @@ class ConstantVerifier extends RecursiveAstVisitor<void> {
           errorToken,
         );
       } else if (error is NonExhaustiveError && reportNonExhaustive) {
-        // TODO(paulberry): instead of using SimpleDartBuffer, use an
-        // analyzer-specific class that implements DartBuffer and captures the
-        // information needed for quick assists.
         var errorBuffer = SimpleDartBuffer();
         error.witness.toDart(errorBuffer, forCorrection: false);
-        var correctionBuffer = SimpleDartBuffer();
-        error.witness.toDart(correctionBuffer, forCorrection: true);
+        var correctionTextBuffer = SimpleDartBuffer();
+        var correctionDataBuffer = AnalyzerDartTemplateBuffer();
+        error.witness.toDart(correctionTextBuffer, forCorrection: true);
+        error.witness.toDart(correctionDataBuffer, forCorrection: true);
         _errorReporter.reportErrorForToken(
           isSwitchExpression
               ? CompileTimeErrorCode.NON_EXHAUSTIVE_SWITCH_EXPRESSION
               : CompileTimeErrorCode.NON_EXHAUSTIVE_SWITCH_STATEMENT,
           switchKeyword,
-          [scrutineeType, errorBuffer.toString(), correctionBuffer.toString()],
+          [
+            scrutineeType,
+            errorBuffer.toString(),
+            correctionTextBuffer.toString(),
+          ],
+          [],
+          correctionDataBuffer.isComplete ? correctionDataBuffer.parts : null,
         );
       }
     }

pkg/analyzer/lib/src/generated/exhaustiveness.dart

@@ -2,6 +2,7 @@
 // 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 'package:_fe_analyzer_shared/src/exhaustiveness/dart_template_buffer.dart';
 import 'package:_fe_analyzer_shared/src/exhaustiveness/exhaustive.dart';
 import 'package:_fe_analyzer_shared/src/exhaustiveness/key.dart';
 import 'package:_fe_analyzer_shared/src/exhaustiveness/path.dart';
@@ -23,6 +24,64 @@ import 'package:analyzer/src/dart/element/type_system.dart';
 import 'package:analyzer/src/dart/resolver/variance.dart';
 import 'package:analyzer/src/generated/constant.dart';
 
+/// The buffer that accumulates types and elements as is, so that they
+/// can be written latter into Dart code that considers imports. It also
+/// accumulates fragments of text, such as syntax `(`, or names of properties.
+class AnalyzerDartTemplateBuffer
+    implements DartTemplateBuffer<DartObject, FieldElement, DartType> {
+  final List<MissingPatternPart> parts = [];
+  bool isComplete = true;
+
+  @override
+  void write(String text) {
+    parts.add(
+      MissingPatternTextPart(text),
+    );
+  }
+
+  @override
+  void writeBoolValue(bool value) {
+    parts.add(
+      MissingPatternTextPart('$value'),
+    );
+  }
+
+  @override
+  void writeCoreType(String name) {
+    parts.add(
+      MissingPatternTextPart(name),
+    );
+  }
+
+  @override
+  void writeEnumValue(FieldElement value, String name) {
+    final enumElement = value.enclosingElement;
+    if (enumElement is! EnumElement) {
+      isComplete = false;
+      return;
+    }
+
+    parts.add(
+      MissingPatternEnumValuePart(
+        enumElement: enumElement,
+        value: value,
+      ),
+    );
+  }
+
+  @override
+  void writeGeneralConstantValue(DartObject value, String name) {
+    isComplete = false;
+  }
+
+  @override
+  void writeGeneralType(DartType type, String name) {
+    parts.add(
+      MissingPatternTypePart(type),
+    );
+  }
+}
+
 class AnalyzerEnumOperations
     implements EnumOperations<DartType, EnumElement, FieldElement, DartObject> {
   const AnalyzerEnumOperations();
@@ -367,6 +426,41 @@ class ExhaustivenessDataForTesting {
   ExhaustivenessDataForTesting(this.objectFieldLookup);
 }
 
+class MissingPatternEnumValuePart extends MissingPatternPart {
+  final EnumElement enumElement;
+  final FieldElement value;
+
+  MissingPatternEnumValuePart({
+    required this.enumElement,
+    required this.value,
+  });
+
+  @override
+  String toString() => value.name;
+}
+
+abstract class MissingPatternPart {}
+
+class MissingPatternTextPart extends MissingPatternPart {
+  final String text;
+
+  MissingPatternTextPart(this.text);
+
+  @override
+  String toString() => text;
+}
+
+class MissingPatternTypePart extends MissingPatternPart {
+  final DartType type;
+
+  MissingPatternTypePart(this.type);
+
+  @override
+  String toString() {
+    return type.getDisplayString(withNullability: true);
+  }
+}
+
 class PatternConverter with SpaceCreator<DartPattern, DartType> {
   final FeatureSet featureSet;
   final AnalyzerExhaustivenessCache cache;

pkg/analyzer/test/src/lint/lint_rule_test.dart

@@ -84,14 +84,24 @@ class CollectingReporter extends ErrorReporter {
   }
 
   @override
-  void reportErrorForNode(ErrorCode errorCode, AstNode node,
-      [List<Object?>? arguments, List<DiagnosticMessage>? messages]) {
+  void reportErrorForNode(
+    ErrorCode errorCode,
+    AstNode node, [
+    List<Object?>? arguments,
+    List<DiagnosticMessage>? messages,
+    Object? data,
+  ]) {
     code = errorCode;
   }
 
   @override
-  void reportErrorForToken(ErrorCode errorCode, Token token,
-      [List<Object?>? arguments, List<DiagnosticMessage>? messages]) {
+  void reportErrorForToken(
+    ErrorCode errorCode,
+    Token token, [
+    List<Object?>? arguments,
+    List<DiagnosticMessage>? messages,
+    Object? data,
+  ]) {
     code = errorCode;
   }
 }

pkg/analyzer_cli/test/mocks.dart

@@ -37,6 +37,9 @@ class MockAnalysisError implements AnalysisError {
   @override
   String? get correctionMessage => null;
 
+  @override
+  Object? get data => throw UnimplementedError();
+
   @override
   DiagnosticMessage get problemMessage => DiagnosticMessageImpl(
       filePath: source.fullName,