[cfe] Add test for issue 37108

Change-Id: Ib027812341cec8b2ed7b69709432a3940f470848
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/107287
Commit-Queue: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>

Author: johnniwinther

pkg/front_end/test/fasta/testing/suite.dart

@@ -10,7 +10,8 @@ import 'dart:convert' show jsonDecode;
 
 import 'dart:io' show File, Platform;
 
-import 'package:kernel/ast.dart' show Library, Component;
+import 'package:kernel/ast.dart'
+    show AwaitExpression, Component, Library, Node, Visitor;
 
 import 'package:kernel/class_hierarchy.dart' show ClassHierarchy;
 
@@ -422,10 +423,37 @@ class Transform extends Step<Component, Component, FastaContext> {
     } finally {
       backendTarget.enabled = false;
     }
+    List<String> errors = VerifyTransformed.verify(component);
+    if (errors.isNotEmpty) {
+      return fail(component, errors.join('\n'));
+    }
     return pass(component);
   }
 }
 
+/// Visitor that checks that the component has been transformed properly.
+// TODO(johnniwinther): Add checks for all nodes that are unsupported after
+// transformation.
+class VerifyTransformed extends Visitor<void> {
+  List<String> errors = [];
+
+  @override
+  void defaultNode(Node node) {
+    node.visitChildren(this);
+  }
+
+  @override
+  void visitAwaitExpression(AwaitExpression node) {
+    errors.add("ERROR: Untransformed await expression: $node");
+  }
+
+  static List<String> verify(Component component) {
+    VerifyTransformed visitor = new VerifyTransformed();
+    component.accept(visitor);
+    return visitor.errors;
+  }
+}
+
 class TestVmTarget extends VmTarget {
   bool enabled = false;
 

pkg/front_end/testcases/await_in_non_async.dart

@@ -0,0 +1,12 @@
+// Copyright (c) 2019, 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.
+
+main() {
+  foo();
+}
+
+foo() {
+  // ignore: await_in_wrong_context
+  await foo();
+}

pkg/front_end/testcases/await_in_non_async.dart.legacy.expect

@@ -0,0 +1,16 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/await_in_non_async.dart:11:3: Error: 'await' can only be used in 'async' or 'async*' methods.
+//   await foo();
+//   ^^^^^
+//
+import self as self;
+
+static method main() → dynamic {
+  self::foo();
+}
+static method foo() → dynamic {
+  await self::foo();
+}

pkg/front_end/testcases/await_in_non_async.dart.outline.expect

@@ -0,0 +1,7 @@
+library;
+import self as self;
+
+static method main() → dynamic
+  ;
+static method foo() → dynamic
+  ;

pkg/front_end/testcases/await_in_non_async.dart.strong.expect

@@ -0,0 +1,16 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/await_in_non_async.dart:11:3: Error: 'await' can only be used in 'async' or 'async*' methods.
+//   await foo();
+//   ^^^^^
+//
+import self as self;
+
+static method main() → dynamic {
+  self::foo();
+}
+static method foo() → dynamic {
+  await self::foo();
+}

pkg/front_end/testcases/await_in_non_async.dart.strong.transformed.expect

@@ -0,0 +1,16 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/await_in_non_async.dart:11:3: Error: 'await' can only be used in 'async' or 'async*' methods.
+//   await foo();
+//   ^^^^^
+//
+import self as self;
+
+static method main() → dynamic {
+  self::foo();
+}
+static method foo() → dynamic {
+  await self::foo();
+}

pkg/front_end/testcases/incremental_initialize_from_dill/await_in_non_async.yaml

@@ -0,0 +1,33 @@
+# Copyright (c) 2019, 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.md file.
+
+type: newworld
+omitPlatform: false
+worlds:
+  - entry: main.dart
+    errors: false
+    warnings: false
+    sources:
+      main.dart: |
+        main() {
+          foo();
+        }
+        foo() {}
+    expectedLibraryCount: 1
+    expectsPlatform: true
+  - entry: main.dart
+    errors: true
+    warnings: false
+    expectInitializeFromDill: false
+    fromComponent: true
+    invalidate:
+      - main.dart
+    sources:
+      main.dart: |
+        main() {
+          await foo();
+        }
+        foo() {}
+    expectedLibraryCount: 1
+    expectsPlatform: true

pkg/front_end/testcases/legacy.status

@@ -7,6 +7,7 @@
 
 DeltaBlue: Fail # Fasta and dartk disagree on static initializers
 ambiguous_exports: RuntimeError # Expected, this file exports two main methods.
+await_in_non_async: Fail # Issue 37108.
 bug31124: RuntimeError # Test has no main method (and we shouldn't add one).
 call: Fail # Test can't run.
 constructor_const_inference: RuntimeError # Test exercises strong mode semantics.  See also Issue #33813.

pkg/front_end/testcases/strong.status

@@ -10,6 +10,7 @@ abstract_members: TypeCheckError
 accessors: RuntimeError
 ambiguous_exports: RuntimeError # Expected, this file exports two main methods.
 argument_mismatch: InstrumentationMismatch # Test assumes Dart 1.0 semantics
+await_in_non_async: Fail # Issue 37108.
 bug21938: TypeCheckError
 bug30695: TypeCheckError
 bug31124: RuntimeError # Test has no main method (and we shouldn't add one).

pkg/front_end/testcases/text_serialization.status

@@ -24,6 +24,7 @@ arrow_function: TextSerializationFailure # Was: Pass
 async_function: TextSerializationFailure # Was: Pass
 async_nested: TextSerializationFailure # Was: Pass
 await: TextSerializationFailure # Was: Pass
+await_in_non_async: TextSerializationFailure
 bad_setter_abstract: TextSerializationFailure # Was: Pass
 bad_store: TextSerializationFailure # Was: Pass
 bad_type_variable_uses_in_supertypes: TextSerializationFailure