Issue 48074. Display inherited default value for super-parameters.

Bug: #48074
Change-Id: I964141c9b2a1ccf4a2d08d6bfff7675aa6df9d5a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/229740
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analysis_server/test/analysis/get_hover_test.dart

@@ -933,6 +933,54 @@ class A {
     expect(hover.elementKind, 'parameter');
   }
 
+  Future<void>
+      test_parameter_ofConstructor_optionalPositional_super_defaultValue_explicit() async {
+    addTestFile('''
+class A {
+  A([int a = 1]);
+}
+class B extends A {
+  B([super.a = 2]);
+}
+''');
+    var hover = await prepareHover('a = 2]');
+    // element
+    expect(hover.elementDescription, '[int a = 2]');
+    expect(hover.elementKind, 'parameter');
+  }
+
+  Future<void>
+      test_parameter_ofConstructor_optionalPositional_super_defaultValue_inherited() async {
+    addTestFile('''
+class A {
+  A([int a = 1]);
+}
+class B extends A {
+  B([super.a]);
+}
+''');
+    var hover = await prepareHover('a]');
+    // element
+    expect(hover.elementDescription, '[int a = 1]');
+    expect(hover.elementKind, 'parameter');
+  }
+
+  Future<void>
+      test_parameter_ofConstructor_optionalPositional_super_defaultValue_inherited2() async {
+    addTestFile('''
+class A {
+  A([num a = 1.2]);
+}
+class B extends A{
+  B([int super.a]);
+}
+''');
+    var hover = await prepareHover('a]');
+    // element
+    expect(hover.elementDescription, '[int a]');
+    expect(hover.elementKind, 'parameter');
+  }
+
   Future<void> test_parameter_reference_fieldFormal() async {
     addTestFile('''
 class A {

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

@@ -1584,23 +1584,19 @@ class DefaultSuperFormalParameterElementImpl
 
   @override
   String? get defaultValueCode {
-    return constantInitializer?.toSource();
-  }
-
-  @override
-  bool get hasDefaultValue {
-    if (super.hasDefaultValue) {
-      return true;
+    final constantInitializer = this.constantInitializer;
+    if (constantInitializer != null) {
+      return constantInitializer.toSource();
     }
-    return computeConstantValue() != null;
-  }
 
-  @override
-  DartObject? computeConstantValue() {
-    if (constantInitializer != null) {
-      return super.computeConstantValue();
+    if (_superConstructorParameterDefaultValue != null) {
+      return superConstructorParameter?.defaultValueCode;
     }
 
+    return null;
+  }
+
+  DartObject? get _superConstructorParameterDefaultValue {
     var superDefault = superConstructorParameter?.computeConstantValue();
     var superDefaultType = superDefault?.type;
     var libraryElement = library;
@@ -1612,6 +1608,15 @@ class DefaultSuperFormalParameterElementImpl
 
     return null;
   }
+
+  @override
+  DartObject? computeConstantValue() {
+    if (constantInitializer != null) {
+      return super.computeConstantValue();
+    }
+
+    return _superConstructorParameterDefaultValue;
+  }
 }
 
 /// The synthetic element representing the declaration of the type `dynamic`.