Issue 50660. Fix 'get Source' for ParameterMember.

Bug: https://github.com/dart-lang/sdk/issues/50660
Change-Id: Ie6af7c60178b2010f4cd5254e563185eb7e27042
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/274603
Reviewed-by: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analyzer/CHANGELOG.md

@@ -1,3 +1,6 @@
+## 5.4.0-dev
+* Bug fixes: 50660
+
 ## 5.3.1
 * Require `collection: ^1.17.0` because we use `elementAtOrNull`.
 

pkg/analyzer/lib/src/dart/element/member.dart

@@ -97,6 +97,9 @@ class ConstructorMember extends ExecutableMember
   @override
   InterfaceType get returnType => type.returnType as InterfaceType;
 
+  @override
+  Source get source => _declaration.source!;
+
   @override
   T? accept<T>(ElementVisitor<T> visitor) =>
       visitor.visitConstructorElement(this);
@@ -396,6 +399,9 @@ class FieldMember extends VariableMember implements FieldElement {
         _typeProvider, baseSetter, _substitution, isLegacy);
   }
 
+  @override
+  Source? get source => _declaration.source;
+
   @override
   T? accept<T>(ElementVisitor<T> visitor) => visitor.visitFieldElement(this);
 
@@ -458,6 +464,9 @@ class FunctionMember extends ExecutableMember implements FunctionElement {
   @override
   String get name => declaration.name;
 
+  @override
+  Source get source => _declaration.source!;
+
   @override
   T? accept<T>(ElementVisitor<T> visitor) {
     return visitor.visitFunctionElement(this);
@@ -620,9 +629,6 @@ abstract class Member implements Element {
   @override
   AnalysisSession? get session => _declaration.session;
 
-  @override
-  Source get source => _declaration.source!;
-
   /// The substitution for type parameters referenced in the base element.
   MapSubstitution get substitution => _substitution;
 
@@ -807,6 +813,9 @@ class MethodMember extends ExecutableMember implements MethodElement {
   @override
   String get name => declaration.name;
 
+  @override
+  Source get source => _declaration.source!;
+
   @override
   T? accept<T>(ElementVisitor<T> visitor) => visitor.visitMethodElement(this);
 
@@ -929,6 +938,9 @@ class ParameterMember extends VariableMember
     return const <ParameterElement>[];
   }
 
+  @override
+  Source? get source => _declaration.source;
+
   @override
   T? accept<T>(ElementVisitor<T> visitor) =>
       visitor.visitParameterElement(this);
@@ -1043,6 +1055,9 @@ class PropertyAccessorMember extends ExecutableMember
   @override
   String get name => declaration.name;
 
+  @override
+  Source get source => _declaration.source!;
+
   @override
   PropertyInducingElement get variable {
     // TODO
@@ -1188,6 +1203,9 @@ class TopLevelVariableMember extends VariableMember
         _typeProvider, baseSetter, _substitution, isLegacy);
   }
 
+  @override
+  Source get source => _declaration.source!;
+
   @override
   T? accept<T>(ElementVisitor<T> visitor) {
     return visitor.visitTopLevelVariableElement(this);

pkg/analyzer/pubspec.yaml

@@ -1,5 +1,5 @@
 name: analyzer
-version: 5.3.1
+version: 5.4.0-dev
 description: This package provides a library that performs static analysis of Dart code.
 repository: https://github.com/dart-lang/sdk/tree/main/pkg/analyzer
 

pkg/analyzer/test/src/dart/resolution/method_invocation_test.dart

@@ -5,6 +5,7 @@
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/src/dart/error/syntactic_errors.dart';
 import 'package:analyzer/src/error/codes.dart';
+import 'package:test/expect.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import 'context_collection_resolution.dart';
@@ -1000,6 +1001,20 @@ CascadeExpression
 ''');
   }
 
+  test_parameterMember_source() async {
+    // See https://github.com/dart-lang/sdk/issues/50660
+    await assertNoErrorsInCode(r'''
+void foo<T>({int? a}) {}
+
+void f() {
+  foo(a: 0);
+}
+''');
+
+    var element = findNode.simple('a:').staticElement!;
+    expect(element.source, isNull);
+  }
+
   test_typeArgumentTypes_generic_inferred_leftTop_dynamic() async {
     await assertNoErrorsInCode('''
 void foo<T extends Object>(T? value) {}