Follow factory redirections when checking case expressions.

tests/compiler/dart2js/resolver_test.dart

 // Copyright (c) 2012, 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 "package:expect/expect.dart";
 import 'dart:async';
 import "package:async_helper/async_helper.dart";
 import 'dart:collection';
 
 import "../../../sdk/lib/_internal/compiler/implementation/resolution/resolution.dart";
@@ skipping 54 matching lines @@
   // testVarSuperclass(); // The parser crashes with 'class Foo extends var'.
   // testOneInterface(); // Generates unexpected error message.
   // testTwoInterfaces(); // Generates unexpected error message.
   testFunctionExpression();
   testNewExpression();
   testTopLevelFields();
   testClassHierarchy();
   testInitializers();
   testThis();
   testSuperCalls();
+  testSwitch();
   testTypeVariables();
   testToString();
   testIndexedOperator();
   testIncrementsAndDecrements();
   testOverrideHashCodeCheck();
   testSupertypeOrder();
   testConstructorArgumentMismatch();
   testConstConstructorAndNonFinalFields();
 }
 
@@ skipping 111 matching lines @@
   FunctionExpression node = fooB.parseNode(compiler);
   visitor.visit(node.body);
   Map mapping = map(visitor);
 
   Send superCall = node.body.asReturn().expression;
   FunctionElement called = mapping[superCall];
   Expect.isNotNull(called);
   Expect.equals(fooA, called);
 }
 
+testSwitch() {
+  MockCompiler compiler = new MockCompiler();
+  compiler.parseScript("class Foo { foo() {"
+      "switch (null) { case '': break; case 2: break; } } }");
+  compiler.resolveStatement("Foo foo;");
+  ClassElement fooElement = compiler.mainApp.find("Foo");
+  FunctionElement funElement = fooElement.lookupLocalMember("foo");
+  compiler.processQueue(compiler.enqueuer.resolution, funElement);
+  Expect.equals(0, compiler.warnings.length);
+  Expect.equals(1, compiler.errors.length);
+  Expect.equals(MessageKind.SWITCH_CASE_TYPES_NOT_EQUAL,
+                compiler.errors[0].message.kind);
+  Expect.equals(2, compiler.infos.length);
+  Expect.equals(MessageKind.SWITCH_CASE_TYPES_NOT_EQUAL_CASE,
+                compiler.infos[0].message.kind);
+  Expect.equals(MessageKind.SWITCH_CASE_TYPES_NOT_EQUAL_CASE,
+                compiler.infos[1].message.kind);
+}
+
 testThis() {
   MockCompiler compiler = new MockCompiler();
   compiler.parseScript("class Foo { foo() { return this; } }");
   compiler.resolveStatement("Foo foo;");
   ClassElement fooElement = compiler.mainApp.find("Foo");
   FunctionElement funElement = fooElement.lookupLocalMember("foo");
   ResolverVisitor visitor =
       new ResolverVisitor(compiler, funElement,
                           new CollectingTreeElements(funElement));
   FunctionExpression function = funElement.parseNode(compiler);
@@ skipping 774 matching lines @@
       }""";
   asyncTest(() => compileScript(script2).then((compiler) {
     expect(compiler,
         [MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS],
         [MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_CONSTRUCTOR,
          MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_CONSTRUCTOR,
          MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_FIELD,
          MessageKind.CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_FIELD]);
   }));
 }