Update language/invalid_returns tests, cf. SDK #41803

Change-Id: I36661c955b9e033fce92481033307525028a5dc3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/149163
Reviewed-by: Leaf Petersen <leafp@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Erik Ernst <eernst@google.com>

tests/language/invalid_returns/async_invalid_return_00_test.dart

@@ -22,18 +22,14 @@ Object? test2() async {
 // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Null>`, no error.
 Object Function() test3 = () async {
   return;
-//^
-// [analyzer] unspecified
-// [cfe] unspecified
 };
 
+// Inferred return type of function literal is `Future<Null>`, no error.
 Object? Function() test4 = () async {
   return;
-//^
-// [analyzer] unspecified
-// [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_03_test.dart

@@ -15,11 +15,9 @@ Future<Object?> test1() async {
 // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Null>`, no error.
 Future<Object?> Function() test2 = () async {
   return;
-//^
-// [analyzer] unspecified
-// [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_04_test.dart

@@ -15,11 +15,9 @@ FutureOr<Object?> test1() async {
 // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Null>`, no error.
 FutureOr<Object?> Function() test2 = () async {
   return;
-//^
-// [analyzer] unspecified
-// [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_05_test.dart

@@ -18,11 +18,9 @@ void test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<int>`, no error.
 void Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_08_test.dart

@@ -18,11 +18,9 @@ void test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Object>`, no error.
 void Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_11_test.dart

@@ -18,11 +18,9 @@ void test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<int?>`, no error.
 void Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_14_test.dart

@@ -18,11 +18,9 @@ void test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<int>`, no error.
 void Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_17_test.dart

@@ -18,11 +18,9 @@ void test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Object>`, no error.
 void Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_20_test.dart

@@ -18,11 +18,9 @@ void test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Object>`, no error.
 void Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_23_test.dart

@@ -25,18 +25,14 @@ Object? test2() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<void>`, no error.
 Object Function() test3 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
+// Inferred return type of function literal is `Future<void>`, no error.
 Object? Function() test4 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_24_test.dart

@@ -25,18 +25,14 @@ Object? test2() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<void?>`, no error.
 Object Function() test3 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
+// Inferred return type of function literal is `Future<void?>`, no error.
 Object? Function() test4 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_25_test.dart

@@ -25,18 +25,14 @@ Object? test2() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<void>`, no error.
 Object Function() test3 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
+// Inferred return type of function literal is `Future<void>`, no error.
 Object? Function() test4 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_32_test.dart

@@ -18,11 +18,9 @@ Future<Object?> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<void>`, no error.
 Future<Object?> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_33_test.dart

@@ -18,11 +18,9 @@ Future<Object?> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<void>`, no error.
 Future<Object?> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_34_test.dart

@@ -18,11 +18,9 @@ Future<Object?> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<void>`, no error.
 Future<Object?> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_35_test.dart

@@ -18,11 +18,9 @@ FutureOr<Object?> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<void>`, no error.
 FutureOr<Object?> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_36_test.dart

@@ -32,11 +32,9 @@ FutureOr<Object> Function() test3 = () async {
   // [cfe] unspecified
 };
 
+// Inferred return type of function literal is `Future<void>`, no error.
 FutureOr<Object?> Function() test4 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_37_test.dart

@@ -18,11 +18,9 @@ FutureOr<Object?> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<void>`, no error.
 FutureOr<Object?> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_41_test.dart

@@ -9,7 +9,7 @@ import 'dart:async';
  * `flatten(S)` is not a subtype of `Tv`.
  */
 
-Future<Future<String>> v = Future.value(Future.value(''));
+Future<Future<String>> v = Future.value(Future<String>.value(''));
 
 Future<String> test1() async {
   return v;

tests/language/invalid_returns/async_invalid_return_45_test.dart

@@ -9,7 +9,7 @@ import 'dart:async';
  * `flatten(S)` is not a subtype of `Tv`.
  */
 
-Future<Future<String>> v = Future.value(Future.value(''));
+Future<Future<String>> v = Future.value(Future<String>.value(''));
 
 FutureOr<String> test1() async {
   return v;

tests/language/invalid_returns/async_invalid_return_47_test.dart

@@ -18,7 +18,8 @@ Future<Null> test1() async {
   // [cfe] unspecified
 }
 
-Future<Nullf> Function() test2 = () async {
+// Inferred return type of function literal is `Future<Null>`.
+Future<Null> Function() test2 = () async {
   return v;
   //     ^
   // [analyzer] unspecified

tests/language/invalid_returns/async_invalid_return_48_test.dart

@@ -18,6 +18,7 @@ Future<Null> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Null>`.
 Future<Null> Function() test2 = () async {
   return v;
   //     ^

tests/language/invalid_returns/async_invalid_return_50_test.dart

@@ -9,7 +9,7 @@ import 'dart:async';
  * and `flatten(S)` is `void` or `void*`.
  */
 
-Future<void> v = Future.value(null);
+Future<void> v = Future.value("Hello");
 
 FutureOr<Null> test1() async {
   return v;
@@ -18,6 +18,7 @@ FutureOr<Null> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Null>`.
 FutureOr<Null> Function() test2 = () async {
   return v;
   //     ^

tests/language/invalid_returns/async_invalid_return_51_test.dart

@@ -9,7 +9,7 @@ import 'dart:async';
  * and `flatten(S)` is `void` or `void*`.
  */
 
-FutureOr<void> v = null;
+FutureOr<void> v = 42;
 
 FutureOr<Null> test1() async {
   return v;
@@ -18,6 +18,7 @@ FutureOr<Null> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Null>`.
 FutureOr<Null> Function() test2 = () async {
   return v;
   //     ^

tests/language/invalid_returns/async_invalid_return_52_test.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 
 /* `return exp;` where `exp` has static type `S` is an error if the future
- * value type of the function is neither `void` nor `dynamic`,
- * and `flatten(S)` is `void` or `void*`.
+ * value type of the function is `void` and `flatten(S)` is not
+ * `void`, `dynamic`, `Null`, `void*`, `dynamic*`, or `Null*`.
  */
 
 int v = 0;
@@ -18,11 +18,9 @@ Future<void> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<int>`, no error.
 Future<void> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_53_test.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 
 /* `return exp;` where `exp` has static type `S` is an error if the future
- * value type of the function is neither `void` nor `dynamic`,
- * and `flatten(S)` is `void` or `void*`.
+ * value type of the function is `void` and `flatten(S)` is not
+ * `void`, `dynamic`, `Null`, `void*`, `dynamic*`, or `Null*`.
  */
 
 Object v = true;
@@ -18,11 +18,9 @@ Future<void> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Object>`, no error.
 Future<void> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_54_test.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 
 /* `return exp;` where `exp` has static type `S` is an error if the future
- * value type of the function is neither `void` nor `dynamic`,
- * and `flatten(S)` is `void` or `void*`.
+ * value type of the function is `void` and `flatten(S)` is not
+ * `void`, `dynamic`, `Null`, `void*`, `dynamic*`, or `Null*`.
  */
 
 FutureOr<int> v = 0;
@@ -18,11 +18,9 @@ Future<void> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<int>`, no error.
 Future<void> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_55_test.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 
 /* `return exp;` where `exp` has static type `S` is an error if the future
- * value type of the function is neither `void` nor `dynamic`,
- * and `flatten(S)` is `void` or `void*`.
+ * value type of the function is `void` and `flatten(S)` is not
+ * `void`, `dynamic`, `Null`, `void*`, `dynamic*`, or `Null*`.
  */
 
 Future<int> v = Future.value(0);
@@ -18,11 +18,9 @@ Future<void> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<int>`, no error.
 Future<void> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_56_test.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 
 /* `return exp;` where `exp` has static type `S` is an error if the future
- * value type of the function is neither `void` nor `dynamic`,
- * and `flatten(S)` is `void` or `void*`.
+ * value type of the function is `void` and `flatten(S)` is not
+ * `void`, `dynamic`, `Null`, `void*`, `dynamic*`, or `Null*`.
  */
 
 int v = 0;
@@ -18,11 +18,9 @@ FutureOr<void> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<int>`, no error.
 FutureOr<void> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_57_test.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 
 /* `return exp;` where `exp` has static type `S` is an error if the future
- * value type of the function is neither `void` nor `dynamic`,
- * and `flatten(S)` is `void` or `void*`.
+ * value type of the function is `void` and `flatten(S)` is not
+ * `void`, `dynamic`, `Null`, `void*`, `dynamic*`, or `Null*`.
  */
 
 Object v = true;
@@ -18,11 +18,9 @@ FutureOr<void> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<Object>`, no error.
 FutureOr<void> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_58_test.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 
 /* `return exp;` where `exp` has static type `S` is an error if the future
- * value type of the function is neither `void` nor `dynamic`,
- * and `flatten(S)` is `void` or `void*`.
+ * value type of the function is `void` and `flatten(S)` is not
+ * `void`, `dynamic`, `Null`, `void*`, `dynamic*`, or `Null*`.
  */
 
 FutureOr<int> v = 0;
@@ -18,11 +18,9 @@ FutureOr<void> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<int>`, no error.
 FutureOr<void> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/async_invalid_return_59_test.dart

@@ -5,8 +5,8 @@
 import 'dart:async';
 
 /* `return exp;` where `exp` has static type `S` is an error if the future
- * value type of the function is neither `void` nor `dynamic`,
- * and `flatten(S)` is `void` or `void*`.
+ * value type of the function is `void` and `flatten(S)` is not
+ * `void`, `dynamic`, `Null`, `void*`, `dynamic*`, or `Null*`.
  */
 
 Future<int> v = Future.value(0);
@@ -18,11 +18,9 @@ FutureOr<void> test1() async {
   // [cfe] unspecified
 }
 
+// Inferred return type of function literal is `Future<int>`, no error.
 FutureOr<void> Function() test2 = () async {
   return v;
-  //     ^
-  // [analyzer] unspecified
-  // [cfe] unspecified
 };
 
 void main() {

tests/language/invalid_returns/sync_invalid_return_27_test.dart

@@ -8,7 +8,8 @@ import 'dart:async';
  * and `T` is not `void` or `dynamic`.
  */
 
-void v = null;
+void v = 42;
+
 Null test() {
   return v;
   //     ^