#2138. Add more tests for functions with a short body (#2958)

Add more tests for functions with a short body. Note that Language/Functions/function_body_short_syntax_A02_t0{1,2,3,4}.dart have intentional syntax errors.

Language/Functions/element_type_A01_t01.dart

@@ -17,6 +17,7 @@
 /// `T`, and `S` is of the form `Iterable<U>`, it is a compile-time error to
 /// yield an expression whose static type isn't assignable to `U`.
 /// @author [email protected]
+/// @issue 53054
 
 import "dart:async";
 

Language/Functions/element_type_A01_t02.dart

@@ -17,6 +17,7 @@
 /// `T`, and `S` is of the form `Iterable<U>`, it is a compile-time error to
 /// yield an expression whose static type isn't assignable to `U`.
 /// @author [email protected]
+/// @issue 53054
 
 import "dart:async";
 

Language/Functions/element_type_A02_t01.dart

@@ -18,6 +18,7 @@
 /// `T`, and `S` is of the form `Stream<U>`, it is a compile-time error to
 /// yield an expression whose static type isn't assignable to `U`.
 /// @author [email protected]
+/// @issue 53054
 
 import "dart:async";
 

Language/Functions/element_type_A02_t02.dart

@@ -18,6 +18,7 @@
 /// `T`, and `S` is of the form `Stream<U>`, it is a compile-time error to
 /// yield an expression whose static type isn't assignable to `U`.
 /// @author [email protected]
+/// @issue 53054
 
 import "dart:async";
 

Language/Functions/function_body_short_syntax_t01.dart → Language/Functions/function_body_short_syntax_A01_t01.dart

@@ -2,20 +2,18 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-/// @assertion A function body of the form => e is equivalent to a body of
-/// the form {return e;} or the form async => e which is equivalent to a body
-/// of the form async {return e;}.
-///
-/// @description Checks that the function body of the form => e is equivalent
-/// to a body of the form {return e;}.
+/// @assertion A function body is either:
+/// ...
+/// - of the form `=> e` or the form `async => e`, which both return the value
+///   of the expression `e` as if by a `return e`.
 ///
+/// @description Checks that the function body of the form `=> e` is equivalent
+/// to a body of the form `{return e;}`.
 /// @author msyabro
 
 import "../../Utils/expect.dart";
 
 main() {
-  int x = 2;
-
   foo1() => 1;
   foo2() {return 1;}
   bar1(int val) => val * 2;

Language/Functions/function_body_short_syntax_t02.dart → Language/Functions/function_body_short_syntax_A01_t02.dart

@@ -2,12 +2,13 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-/// @assertion A function body of the form => e is equivalent to a body of
-/// the form {return e;} or the form async => e which is equivalent to a body
-/// of the form async {return e;}.
+/// @assertion A function body is either:
+/// ...
+/// - of the form `=> e` or the form `async => e`, which both return the value
+///   of the expression `e` as if by a `return e`.
 ///
-/// @description Checks that the function body of the form async => e is
-/// equivalent to a body of the form async {return e;}.
+/// @description Checks that the function body of the form `async => e` is
+/// equivalent to a body of the form `async {return e;}`.
 /// @author [email protected]
 
 import 'dart:async';

Language/Functions/function_body_short_syntax_A02_t01.dart

@@ -0,0 +1,56 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion A function body is either:
+/// ...
+/// - of the form `=> e` or the form `async => e`, which both return the value
+///   of the expression `e` as if by a `return e`. The other modifiers do not
+///   apply here, because they apply only to generators, discussed below.
+///   Generators are not allowed to explicitly return anything, objects are
+///   added to the generated stream or iterable using `yield` or `yield*`.
+///
+/// @description Checks that it is a compile-time error if a function with a
+/// short syntax contains `async*` modifier.
+/// @author [email protected]
+
+import 'dart:async';
+
+Stream<int> f1() async* => 1;
+//                      ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Stream<int> f2() async* => [1];
+//                      ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Stream<int> f3() async* => Stream.fromIterable([1]);
+//                      ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Stream<void> f4() async* => 1 as dynamic;
+//                       ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Stream<void> f5() async* => null;
+//                       ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Stream<void> f6() async* => print(""); // print("") returns void
+//                       ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+FutureOr<Stream<int>> f7() async* => 1;
+//                      ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+main() {
+  print(f1);
+  print(f2);
+  print(f3);
+  print(f4);
+  print(f5);
+  print(f6);
+  print(f7);
+}

Language/Functions/function_body_short_syntax_A02_t02.dart

@@ -0,0 +1,56 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion A function body is either:
+/// ...
+/// - of the form `=> e` or the form `async => e`, which both return the value
+///   of the expression `e` as if by a `return e`. The other modifiers do not
+///   apply here, because they apply only to generators, discussed below.
+///   Generators are not allowed to explicitly return anything, objects are
+///   added to the generated stream or iterable using `yield` or `yield*`.
+///
+/// @description Checks that it is a compile-time error if a function with a
+/// short syntax contains `sync*` modifier.
+/// @author [email protected]
+
+import 'dart:async';
+
+Iterable<int> f1() sync* => 1;
+//                       ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Iterable<int> f2() sync* => [1];
+//                       ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Iterable<int> f3() sync* => Stream.fromIterable([1]);
+//                       ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Iterable<void> f4() sync* => 1 as dynamic;
+//                        ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Iterable<void> f5() sync* => null;
+//                        ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+Iterable<void> f6() sync* => print(""); // print("") returns void
+//                        ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+FutureOr<Iterable<int>> f7() sync* => 1;
+//                                 ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+
+main() {
+  print(f1);
+  print(f2);
+  print(f3);
+  print(f4);
+  print(f5);
+  print(f6);
+  print(f7);
+}

Language/Functions/function_body_short_syntax_A02_t03.dart

@@ -0,0 +1,83 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion A function body is either:
+/// ...
+/// - of the form `=> e` or the form `async => e`, which both return the value
+///   of the expression `e` as if by a `return e`. The other modifiers do not
+///   apply here, because they apply only to generators, discussed below.
+///   Generators are not allowed to explicitly return anything, objects are
+///   added to the generated stream or iterable using `yield` or `yield*`.
+///
+/// @description Checks that it is a compile-time error if a method with a
+/// short syntax contains `async*` modifier.
+/// @author [email protected]
+
+import 'dart:async';
+
+class C {
+  static Stream<int> staticMethod() async* => 1;
+//                                         ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Stream<int> instanceMethod() async* => 1;
+//                                    ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+mixin M {
+  static Stream<int> staticMethod() async* => 1;
+//                                         ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Stream<int> instanceMethod() async* => 1;
+//                                    ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  e0;
+  static Stream<int> staticMethod() async* => 1;
+//                                         ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Stream<int> instanceMethod() async* => 1;
+//                                    ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+class A {}
+
+extension Ext on A {
+  static Stream<int> staticMethod() async* => 1;
+//                                         ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Stream<int> instanceMethod() async* => 1;
+//                                    ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+extension type ET(int _) {
+  static Stream<int> staticMethod() async* => 1;
+//                                         ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Stream<int> instanceMethod() async* => 1;
+//                                    ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(M);
+  print(E);
+  print(A);
+  print(ET);
+}

Language/Functions/function_body_short_syntax_A02_t04.dart

@@ -0,0 +1,83 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion A function body is either:
+/// ...
+/// - of the form `=> e` or the form `async => e`, which both return the value
+///   of the expression `e` as if by a `return e`. The other modifiers do not
+///   apply here, because they apply only to generators, discussed below.
+///   Generators are not allowed to explicitly return anything, objects are
+///   added to the generated stream or iterable using `yield` or `yield*`.
+///
+/// @description Checks that it is a compile-time error if a method with a
+/// short syntax contains `sync*` modifier.
+/// @author [email protected]
+
+import 'dart:async';
+
+class C {
+  static Iterable<int> staticMethod() sync* => 1;
+//                                          ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Iterable<int> instanceMethod() sync* => 1;
+//                                     ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+mixin M {
+  static Iterable<int> staticMethod() sync* => 1;
+//                                          ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Iterable<int> instanceMethod() sync* => 1;
+//                                     ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+enum E {
+  e0;
+  static Iterable<int> staticMethod() sync* => 1;
+//                                          ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Iterable<int> instanceMethod() sync* => 1;
+//                                     ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+class A {}
+
+extension Ext on A {
+  static Iterable<int> staticMethod() sync* => 1;
+//                                          ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Iterable<int> instanceMethod() sync* => 1;
+//                                     ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+extension type ET(int _) {
+  static Iterable<int> staticMethod() sync* => 1;
+//                                          ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+  Iterable<int> instanceMethod() sync* => 1;
+//                                     ^^
+// [analyzer] unspecified
+// [cfe] unspecified
+}
+
+main() {
+  print(C);
+  print(M);
+  print(E);
+  print(A);
+  print(ET);
+}

Language/Functions/function_body_short_syntax_A03_t01.dart

@@ -0,0 +1,29 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// @assertion A function body is either:
+/// ...
+/// - of the form `=> e` or the form `async => e`, which both return the value
+///   of the expression `e` as if by a `return e`. ...  Let `T` be the declared
+///   return type of the function that has this body. It is a compile-time error
+///   if one of the following conditions hold:
+///   – The function is synchronous, `T` is not `void`, and it would have been a
+///     compile-time error to declare the function with the body `{ return e; }`
+///     rather than `=> e`.
+///
+/// @description Checks that it is not an error to declare a synchronous
+/// function with a short syntax and the return type `void`.
+/// @author [email protected]
+
+void f1() => 1;
+void f2() => null;
+void f3<T>(T t) => t;
+void f4() => print("");
+
+main() {
+  print(f1);
+  print(f2);
+  print(f3);
+  print(f4);
+}