[cfe] Add test for issue 42459

Closes #42459

Change-Id: I77215b0b6dcdf4cdbfd07796c41478087607359f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/155860
Reviewed-by: Dmitry Stefantsov <[email protected]>

Author: johnniwinther

pkg/front_end/testcases/nnbd/issue42459.dart

@@ -0,0 +1,23 @@
+// 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.
+
+test() {
+  (x) {
+    if (x) {
+      return 1;
+    } else {
+      return;
+    }
+  };
+
+  void local(x) {
+    if (x) {
+      return print('');
+    } else {
+      return;
+    }
+  }
+}
+
+main() {}

pkg/front_end/testcases/nnbd/issue42459.dart.outline.expect

@@ -0,0 +1,7 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+
+static method test() → dynamic
+  ;
+static method main() → dynamic
+  ;

pkg/front_end/testcases/nnbd/issue42459.dart.strong.expect

@@ -0,0 +1,32 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/nnbd/issue42459.dart:10:7: Error: A value must be explicitly returned from a non-void function.
+//       return;
+//       ^
+//
+import self as self;
+import "dart:core" as core;
+
+static method test() → dynamic {
+  (dynamic x) → core::int? {
+    if(x as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
+      return 1;
+    }
+    else {
+      return let final<BottomType> #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue42459.dart:10:7: Error: A value must be explicitly returned from a non-void function.
+      return;
+      ^" in null;
+    }
+  };
+  function local(dynamic x) → void {
+    if(x as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
+      return core::print("");
+    }
+    else {
+      return;
+    }
+  }
+}
+static method main() → dynamic {}

pkg/front_end/testcases/nnbd/issue42459.dart.strong.transformed.expect

@@ -0,0 +1,32 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/nnbd/issue42459.dart:10:7: Error: A value must be explicitly returned from a non-void function.
+//       return;
+//       ^
+//
+import self as self;
+import "dart:core" as core;
+
+static method test() → dynamic {
+  (dynamic x) → core::int? {
+    if(x as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
+      return 1;
+    }
+    else {
+      return let final<BottomType> #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue42459.dart:10:7: Error: A value must be explicitly returned from a non-void function.
+      return;
+      ^" in null;
+    }
+  };
+  function local(dynamic x) → void {
+    if(x as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
+      return core::print("");
+    }
+    else {
+      return;
+    }
+  }
+}
+static method main() → dynamic {}

pkg/front_end/testcases/nnbd/issue42459.dart.textual_outline.expect

@@ -0,0 +1,2 @@
+test() {}
+main() {}

pkg/front_end/testcases/nnbd/issue42459.dart.textual_outline_modelled.expect

@@ -0,0 +1,2 @@
+main() {}
+test() {}

pkg/front_end/testcases/nnbd/issue42459.dart.weak.expect

@@ -0,0 +1,32 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/nnbd/issue42459.dart:10:7: Error: A value must be explicitly returned from a non-void function.
+//       return;
+//       ^
+//
+import self as self;
+import "dart:core" as core;
+
+static method test() → dynamic {
+  (dynamic x) → core::int? {
+    if(x as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
+      return 1;
+    }
+    else {
+      return let final<BottomType> #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue42459.dart:10:7: Error: A value must be explicitly returned from a non-void function.
+      return;
+      ^" in null;
+    }
+  };
+  function local(dynamic x) → void {
+    if(x as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
+      return core::print("");
+    }
+    else {
+      return;
+    }
+  }
+}
+static method main() → dynamic {}

pkg/front_end/testcases/nnbd/issue42459.dart.weak.transformed.expect

@@ -0,0 +1,32 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/nnbd/issue42459.dart:10:7: Error: A value must be explicitly returned from a non-void function.
+//       return;
+//       ^
+//
+import self as self;
+import "dart:core" as core;
+
+static method test() → dynamic {
+  (dynamic x) → core::int? {
+    if(x as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
+      return 1;
+    }
+    else {
+      return let final<BottomType> #t1 = invalid-expression "pkg/front_end/testcases/nnbd/issue42459.dart:10:7: Error: A value must be explicitly returned from a non-void function.
+      return;
+      ^" in null;
+    }
+  };
+  function local(dynamic x) → void {
+    if(x as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
+      return core::print("");
+    }
+    else {
+      return;
+    }
+  }
+}
+static method main() → dynamic {}