[cfe] Add test to verify legacy main method requirements

Change-Id: I3173d85ffe1d92840458fb28fcf2073bec3899ad
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/166241
Reviewed-by: Jens Johansen <jensj@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

pkg/front_end/testcases/general/main_declaration.dart

@@ -0,0 +1,7 @@
+// Copyright (c) 2020, 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.
+
+import 'main_declaration_lib.dart';
+
+main() {}

pkg/front_end/testcases/general/main_declaration.dart.outline.expect

@@ -0,0 +1,14 @@
+library;
+import self as self;
+
+import "org-dartlang-testcase:///main_declaration_lib.dart";
+
+static method main() → dynamic
+  ;
+
+library;
+import self as self2;
+import "dart:core" as core;
+
+static method main(core::String* args) → dynamic
+  ;

pkg/front_end/testcases/general/main_declaration.dart.strong.expect

@@ -0,0 +1,12 @@
+library;
+import self as self;
+
+import "org-dartlang-testcase:///main_declaration_lib.dart";
+
+static method main() → dynamic {}
+
+library;
+import self as self2;
+import "dart:core" as core;
+
+static method main(core::String* args) → dynamic {}

pkg/front_end/testcases/general/main_declaration.dart.strong.transformed.expect

@@ -0,0 +1,12 @@
+library;
+import self as self;
+
+import "org-dartlang-testcase:///main_declaration_lib.dart";
+
+static method main() → dynamic {}
+
+library;
+import self as self2;
+import "dart:core" as core;
+
+static method main(core::String* args) → dynamic {}

pkg/front_end/testcases/general/main_declaration.dart.textual_outline.expect

@@ -0,0 +1,3 @@
+import 'main_declaration_lib.dart';
+
+main() {}

pkg/front_end/testcases/general/main_declaration.dart.textual_outline_modelled.expect

@@ -0,0 +1,3 @@
+import 'main_declaration_lib.dart';
+
+main() {}

pkg/front_end/testcases/general/main_declaration_lib.dart

@@ -0,0 +1,6 @@
+// Copyright (c) 2020, 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.
+
+// This would be an invalid main declaration in a null safe library.
+main(String args) {}

pkg/front_end/testcases/nnbd_mixed/main_declaration.dart

@@ -0,0 +1,9 @@
+// Copyright (c) 2020, 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.
+
+// @dart=2.8
+
+import 'main_declaration_lib.dart';
+
+main() {}

pkg/front_end/testcases/nnbd_mixed/main_declaration.dart.textual_outline.expect

@@ -0,0 +1,4 @@
+// @dart = 2.8
+import 'main_declaration_lib.dart';
+
+main() {}

pkg/front_end/testcases/nnbd_mixed/main_declaration.dart.textual_outline_modelled.expect

@@ -0,0 +1,4 @@
+// @dart = 2.8
+import 'main_declaration_lib.dart';
+
+main() {}

pkg/front_end/testcases/nnbd_mixed/main_declaration.dart.weak.expect

@@ -0,0 +1,12 @@
+library;
+import self as self;
+
+import "org-dartlang-testcase:///main_declaration_lib.dart";
+
+static method main() → dynamic {}
+
+library;
+import self as self2;
+import "dart:core" as core;
+
+static method main(core::String* args) → dynamic {}

pkg/front_end/testcases/nnbd_mixed/main_declaration.dart.weak.transformed.expect

@@ -0,0 +1,12 @@
+library;
+import self as self;
+
+import "org-dartlang-testcase:///main_declaration_lib.dart";
+
+static method main() → dynamic {}
+
+library;
+import self as self2;
+import "dart:core" as core;
+
+static method main(core::String* args) → dynamic {}

pkg/front_end/testcases/nnbd_mixed/main_declaration_lib.dart

@@ -0,0 +1,8 @@
+// Copyright (c) 2020, 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.
+
+// @dart=2.8
+
+// This would be an invalid main declaration in a null safe library.
+main(String args) {}