[analysis_server] Insert "required" keyword in created methods/added named parameters

Fixes https://github.com/Dart-Code/Dart-Code/issues/3770.

Change-Id: I954b9bbcac72ffc7a7b6e168214971bf1786872a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/228564
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

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

@@ -29,11 +29,9 @@ main() {
   new A(1, b: 2, named: 3.0);
 }
 ''');
-    // TODO(brianwilkerson) The fix should make added named parameters be
-    //  `required`. I'm leaving it as is to match the current behavior.
     await assertHasFix('''
 class A {
-  A(int a, {int b = 0, double named}) {}
+  A(int a, {int b = 0, required double named}) {}
 }
 
 main() {
@@ -54,7 +52,7 @@ main() {
 ''');
     await assertHasFix('''
 class A {
-  A(int a, {double named}) {}
+  A(int a, {required double named}) {}
 }
 
 main() {
@@ -75,7 +73,7 @@ main() {
 ''');
     await assertHasFix('''
 class A {
-  A({int named}) {}
+  A({required int named}) {}
 }
 
 main() {
@@ -96,7 +94,7 @@ main() {
 ''');
     await assertHasFix('''
 class A {
-  A.aaa({int named}) {}
+  A.aaa({required int named}) {}
 }
 
 main() {
@@ -114,7 +112,7 @@ main() {
 }
 ''');
     await assertHasFix('''
-test(int a, {int b: 0, double named}) {}
+test(int a, {int b: 0, required double named}) {}
 
 main() {
   test(1, b: 2, named: 3.0);
@@ -131,7 +129,7 @@ main() {
 }
 ''');
     await assertHasFix('''
-test(int a, {double named}) {}
+test(int a, {required double named}) {}
 
 main() {
   test(1, named: 2.0);
@@ -148,7 +146,7 @@ main() {
 }
 ''');
     await assertHasFix('''
-test({int named}) {}
+test({required int named}) {}
 
 main() {
   test(named: 42);
@@ -168,7 +166,7 @@ class A {
 ''');
     await assertHasFix('''
 class A {
-  test(int a, {int b: 0, double named}) {}
+  test(int a, {int b: 0, required double named}) {}
 
   main() {
     test(1, b: 2, named: 3.0);
@@ -202,7 +200,7 @@ class A {
 ''');
     await assertHasFix('''
 class A {
-  test(int a, {double named}) {}
+  test(int a, {required double named}) {}
 
   main() {
     test(1, named: 2.0);
@@ -223,7 +221,7 @@ class A {
 ''');
     await assertHasFix('''
 class A {
-  test({int named}) {}
+  test({required int named}) {}
 
   main() {
     test(named: 42);

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

@@ -415,17 +415,21 @@ class A {
     await resolveTestCode('''
 class A {
   void f() {
-    myUndefinedMethod(0, bbb: 1.0, ccc: '2');
+    var c = '2';
+    int? d;
+    myUndefinedMethod(0, bbb: 1.0, ccc: c, ddd: d);
   }
 }
 ''');
     await assertHasFix('''
 class A {
   void f() {
-    myUndefinedMethod(0, bbb: 1.0, ccc: '2');
+    var c = '2';
+    int? d;
+    myUndefinedMethod(0, bbb: 1.0, ccc: c, ddd: d);
   }
 
-  void myUndefinedMethod(int i, {double bbb, String ccc}) {}
+  void myUndefinedMethod(int i, {required double bbb, required String ccc, int? ddd}) {}
 }
 ''');
     // linked positions

pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart

@@ -578,9 +578,15 @@ class DartEditBuilderImpl extends EditBuilderImpl implements DartEditBuilder {
       Expression argument, int index, Set<String> usedNames) {
     // append type name
     var type = argument.staticType;
+    var library = dartFileEditBuilder.resolvedUnit.libraryElement;
     if (type == null || type.isBottom || type.isDartCoreNull) {
       type = DynamicTypeImpl.instance;
     }
+    if (argument is NamedExpression &&
+        library.isNonNullableByDefault &&
+        type.nullabilitySuffix == NullabilitySuffix.none) {
+      write('required ');
+    }
     if (writeType(type, addSupertypeProposals: true, groupName: 'TYPE$index')) {
       write(' ');
     }

pkg/analyzer_plugin/test/src/utilities/change_builder/change_builder_dart_test.dart

@@ -1145,7 +1145,10 @@ f(int i, String s) {
       });
     });
     var edit = getEdit(builder);
-    expect(edit.replacement, equalsIgnoringWhitespace('String s, {int index}'));
+    var expectedReplacement = this is WithoutNullSafetyMixin
+        ? 'String s, {int index}'
+        : 'String s, {required int index}';
+    expect(edit.replacement, equalsIgnoringWhitespace(expectedReplacement));
   }
 
   Future<void> test_writeParametersMatchingArguments_required() async {