Move check for setter formal parameters to AstBuilder.

Now every setter after parsing has exactly one required positional
formal parameter. This will cause setter elements have exactly one
formal parameter, and let us avoid checking for it in multiple places.

Remove CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER

Add ParserErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER

Change-Id: I80a6f3f6e51ac2ed2f6ddb49d059c2d78ff64b2e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/441830
Reviewed-by: Paul Berry <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: scheglov

pkg/analysis_server/lib/src/services/correction/error_fix_status.yaml

@@ -1662,8 +1662,6 @@ CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_OPERATOR_MINUS:
   notes: |-
     Fixes could include (1) removing all past the first parameter, and (2)
     removing all but a singular used parameter, if only one is used.
-CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER:
-  status: needsFix
 CompileTimeErrorCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS:
   status: hasFix
 CompileTimeErrorCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS_ANONYMOUS_FUNCTION:
@@ -3319,6 +3317,8 @@ ParserErrorCode.WITH_BEFORE_EXTENDS:
   status: needsFix
   notes: |-
     Move the extends clause.
+ParserErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER:
+  status: needsFix
 ParserErrorCode.WRONG_SEPARATOR_FOR_POSITIONAL_PARAMETER:
   status: hasFix
 ParserErrorCode.WRONG_TERMINATOR_FOR_PARAMETER_GROUP:

pkg/analysis_server/test/lsp/completion_dart_test.dart

@@ -3306,8 +3306,8 @@ void f() {
             .toList();
     expect(setters, [
       'stringSetter (String)',
-      'noArgSetter',
-      'multiArgSetter',
+      'noArgSetter (dynamic)',
+      'multiArgSetter (dynamic)',
       // Because of how we extract the type name, we don't currently support
       // this.
       'functionSetter',

pkg/analyzer/lib/src/dart/ast/extensions.dart

@@ -197,6 +197,16 @@ extension FormalParameterExtension on FormalParameter {
   }
 }
 
+extension FormalParameterImplExtension on FormalParameterImpl {
+  FormalParameterImpl get notDefault {
+    var self = this;
+    if (self is DefaultFormalParameterImpl) {
+      return self.parameter;
+    }
+    return self;
+  }
+}
+
 // TODO(scheglov): https://github.com/dart-lang/sdk/issues/43608
 extension IdentifierExtension on Identifier {
   Element? get readElement {

pkg/analyzer/lib/src/dart/error/syntactic_errors.g.dart

@@ -2038,6 +2038,13 @@ class ParserErrorCode extends DiagnosticCode {
     correctionMessage: "Try moving the extends clause before the with clause.",
   );
 
+  static const ParserErrorCode WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER =
+      ParserErrorCode(
+        'WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER',
+        "Setters must declare exactly one required positional parameter.",
+        hasPublishedDocs: true,
+      );
+
   static const ParserErrorCode
   WRONG_SEPARATOR_FOR_POSITIONAL_PARAMETER = ParserErrorCode(
     'WRONG_SEPARATOR_FOR_POSITIONAL_PARAMETER',

pkg/analyzer/lib/src/diagnostic/diagnostic_code_values.g.dart

@@ -583,7 +583,6 @@ const List<DiagnosticCode> diagnosticCodeValues = [
   CompileTimeErrorCode.WRONG_EXPLICIT_TYPE_PARAMETER_VARIANCE_IN_SUPERINTERFACE,
   CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_OPERATOR,
   CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_OPERATOR_MINUS,
-  CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER,
   CompileTimeErrorCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS,
   CompileTimeErrorCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS_ANONYMOUS_FUNCTION,
   CompileTimeErrorCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS_CONSTRUCTOR,
@@ -924,6 +923,7 @@ const List<DiagnosticCode> diagnosticCodeValues = [
   ParserErrorCode.VAR_TYPEDEF,
   ParserErrorCode.VOID_WITH_TYPE_ARGUMENTS,
   ParserErrorCode.WITH_BEFORE_EXTENDS,
+  ParserErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER,
   ParserErrorCode.WRONG_SEPARATOR_FOR_POSITIONAL_PARAMETER,
   ParserErrorCode.WRONG_TERMINATOR_FOR_PARAMETER_GROUP,
   PubspecWarningCode.ASSET_DIRECTORY_DOES_NOT_EXIST,

pkg/analyzer/lib/src/error/codes.g.dart

@@ -5879,14 +5879,6 @@ class CompileTimeErrorCode extends DiagnosticCode {
     uniqueName: 'WRONG_NUMBER_OF_PARAMETERS_FOR_OPERATOR_MINUS',
   );
 
-  ///  No parameters.
-  static const CompileTimeErrorCode WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER =
-      CompileTimeErrorCode(
-        'WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER',
-        "Setters must declare exactly one required positional parameter.",
-        hasPublishedDocs: true,
-      );
-
   ///  Parameters:
   ///  0: the name of the type being referenced (<i>G</i>)
   ///  1: the number of type parameters that were declared

pkg/analyzer/lib/src/fasta/ast_builder.dart

@@ -1378,31 +1378,15 @@ class AstBuilder extends StackListener {
     var bodyObject = pop();
     pop(); // initializers
     pop(); // separator
-    var parameters = pop() as FormalParameterListImpl?;
+    var formalParameters = pop() as FormalParameterListImpl?;
     var typeParameters = pop() as TypeParameterListImpl?;
     var name = pop();
     var returnType = pop() as TypeAnnotationImpl?;
     var modifiers = pop() as _Modifiers?;
     var metadata = pop() as List<AnnotationImpl>?;
     var comment = _findComment(metadata, beginToken);
 
-    assert(parameters != null || optional('get', getOrSet!));
-
-    FunctionBodyImpl body;
-    if (bodyObject is FunctionBodyImpl) {
-      body = bodyObject;
-    } else if (bodyObject is _RedirectingFactoryBody) {
-      body = EmptyFunctionBodyImpl(semicolon: endToken);
-    } else {
-      internalProblem(
-        templateInternalProblemUnhandled.withArguments(
-          "${bodyObject.runtimeType}",
-          "bodyObject",
-        ),
-        beginToken.charOffset,
-        uri,
-      );
-    }
+    assert(formalParameters != null || optional('get', getOrSet!));
 
     Token? operatorKeyword;
     SimpleIdentifierImpl nameId;
@@ -1424,7 +1408,27 @@ class AstBuilder extends StackListener {
       );
     }
 
-    checkFieldFormalParameters(parameters);
+    if (getOrSet?.keyword == Keyword.SET) {
+      formalParameters = _ensureSetterFormalParameter(nameId, formalParameters);
+    }
+
+    FunctionBodyImpl body;
+    if (bodyObject is FunctionBodyImpl) {
+      body = bodyObject;
+    } else if (bodyObject is _RedirectingFactoryBody) {
+      body = EmptyFunctionBodyImpl(semicolon: endToken);
+    } else {
+      internalProblem(
+        templateInternalProblemUnhandled.withArguments(
+          "${bodyObject.runtimeType}",
+          "bodyObject",
+        ),
+        beginToken.charOffset,
+        uri,
+      );
+    }
+
+    checkFieldFormalParameters(formalParameters);
     _classLikeBuilder?.members.add(
       MethodDeclarationImpl(
         comment: comment,
@@ -1437,7 +1441,7 @@ class AstBuilder extends StackListener {
         operatorKeyword: operatorKeyword,
         name: nameId.token,
         typeParameters: typeParameters,
-        parameters: parameters,
+        parameters: formalParameters,
         body: body,
       ),
     );
@@ -3615,7 +3619,7 @@ class AstBuilder extends StackListener {
     debugEvent("TopLevelMethod");
 
     var body = pop() as FunctionBodyImpl;
-    var parameters = pop() as FormalParameterListImpl?;
+    var formalParameters = pop() as FormalParameterListImpl?;
     var typeParameters = pop() as TypeParameterListImpl?;
     var name = pop() as SimpleIdentifierImpl;
     var returnType = pop() as TypeAnnotationImpl?;
@@ -3624,6 +3628,11 @@ class AstBuilder extends StackListener {
     var externalKeyword = modifiers?.externalKeyword;
     var metadata = pop() as List<AnnotationImpl>?;
     var comment = _findComment(metadata, beginToken);
+
+    if (getOrSet?.keyword == Keyword.SET) {
+      formalParameters = _ensureSetterFormalParameter(name, formalParameters);
+    }
+
     declarations.add(
       FunctionDeclarationImpl(
         comment: comment,
@@ -3635,7 +3644,7 @@ class AstBuilder extends StackListener {
         name: name.token,
         functionExpression: FunctionExpressionImpl(
           typeParameters: typeParameters,
-          parameters: parameters,
+          parameters: formalParameters,
           body: body,
         ),
       ),
@@ -6229,6 +6238,61 @@ class AstBuilder extends StackListener {
     return constructor;
   }
 
+  FormalParameterListImpl? _ensureSetterFormalParameter(
+    SimpleIdentifierImpl setterName,
+    FormalParameterListImpl? formalParameters,
+  ) {
+    formalParameters ??=
+        throw StateError('Parser has recovery, this never happens.');
+
+    var valueFormalParameter = formalParameters.parameters.firstOrNull;
+    if (valueFormalParameter == null) {
+      if (!formalParameters.leftParenthesis.isSynthetic) {
+        diagnosticReporter.diagnosticReporter?.atToken(
+          setterName.token,
+          ParserErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER,
+        );
+      }
+      var valueNameToken = parser.rewriter.insertSyntheticIdentifier(
+        formalParameters.leftParenthesis,
+      );
+      return FormalParameterListImpl(
+        leftParenthesis: formalParameters.leftParenthesis,
+        parameters: [
+          SimpleFormalParameterImpl(
+            comment: null,
+            metadata: null,
+            covariantKeyword: null,
+            requiredKeyword: null,
+            keyword: null,
+            type: null,
+            name: valueNameToken,
+          ),
+        ],
+        leftDelimiter: null,
+        rightDelimiter: null,
+        rightParenthesis: formalParameters.rightParenthesis,
+      );
+    }
+
+    if (valueFormalParameter.isRequiredPositional &&
+        formalParameters.parameters.length == 1) {
+      return formalParameters;
+    }
+
+    diagnosticReporter.diagnosticReporter?.atToken(
+      setterName.token,
+      ParserErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER,
+    );
+    return FormalParameterListImpl(
+      leftParenthesis: formalParameters.leftParenthesis,
+      parameters: [valueFormalParameter.notDefault],
+      leftDelimiter: null,
+      rightDelimiter: null,
+      rightParenthesis: formalParameters.rightParenthesis,
+    );
+  }
+
   CommentImpl? _findComment(
     List<AnnotationImpl>? metadata,
     Token tokenAfterMetadata,

pkg/analyzer/lib/src/fasta/error_converter.dart

@@ -500,14 +500,6 @@ class FastaErrorReporter {
           diagnosticCode: ScannerErrorCode.UNTERMINATED_STRING_LITERAL,
         );
         return;
-      case "WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER":
-        diagnosticReporter?.atOffset(
-          offset: offset,
-          length: length,
-          diagnosticCode:
-              CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER,
-        );
-        return;
       case "WRONG_SEPARATOR_FOR_POSITIONAL_PARAMETER":
         diagnosticReporter?.atOffset(
           offset: offset,

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

@@ -996,11 +996,6 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
       () {
         TypeAnnotation? returnType = node.returnType;
         if (node.isSetter) {
-          FunctionExpression functionExpression = node.functionExpression;
-          _checkForWrongNumberOfParametersForSetter(
-            node.name,
-            functionExpression.parameters,
-          );
           _checkForNonVoidReturnTypeForSetter(returnType);
         }
         _checkForTypeAnnotationDeferredClass(returnType);
@@ -1234,7 +1229,6 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
       () {
         var returnType = node.returnType;
         if (node.isSetter) {
-          _checkForWrongNumberOfParametersForSetter(node.name, node.parameters);
           _checkForNonVoidReturnTypeForSetter(returnType);
         } else if (node.isOperator) {
           var hasWrongNumberOfParameters =
@@ -5782,31 +5776,6 @@ class ErrorVerifier extends RecursiveAstVisitor<void>
     return false;
   }
 
-  /// Verify that the given setter [parameterList] has only one required
-  /// parameter. The [setterName] is the name of the setter to report problems
-  /// on.
-  ///
-  /// This method assumes that the method declaration was tested to be a setter
-  /// before being called.
-  ///
-  /// See [CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER].
-  void _checkForWrongNumberOfParametersForSetter(
-    Token setterName,
-    FormalParameterList? parameterList,
-  ) {
-    if (parameterList == null) {
-      return;
-    }
-
-    NodeList<FormalParameter> parameters = parameterList.parameters;
-    if (parameters.length != 1 || !parameters[0].isRequiredPositional) {
-      diagnosticReporter.atToken(
-        setterName,
-        CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_SETTER,
-      );
-    }
-  }
-
   void _checkForWrongTypeParameterVarianceInField(FieldDeclarationImpl node) {
     if (_enclosingClass != null) {
       for (var typeParameter in _enclosingClass!.asElement.typeParameters) {