Add bool value types to type inference.

tests/compiler/dart2js/type_inference8_test.dart

Index: tests/compiler/dart2js/type_inference8_test.dart
diff --git a/tests/compiler/dart2js/type_inference8_test.dart b/tests/compiler/dart2js/type_inference8_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..fc2d57819e9b10dd55dae3a87dbd4401359ef910
--- /dev/null
+++ b/tests/compiler/dart2js/type_inference8_test.dart
@@ -0,0 +1,101 @@
+// Copyright (c) 2015, 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:async_helper/async_helper.dart";
+import "package:compiler/src/types/types.dart";
+import "package:expect/expect.dart";
+import 'compiler_helper.dart';
+import 'type_mask_test_helper.dart';
+
+import 'dart:async';
+
+const String TEST1 = r"""
+foo(x) {
+  return x;
+}
+
+bar(x) {
+  if (x) {
+    print("aaa");
+  } else {
+    print("bbb");
+  }
+}
+
+main() {
+  bar(foo(false));
+  bar(foo(foo(false)));
+}
+""";
+
+Future runTest1() {
+  Uri uri = new Uri(scheme: 'source');
+  var compiler = compilerFor(TEST1, uri);
+  return compiler.runCompiler(uri).then((_) {
+    var typesTask = compiler.typesTask;
+    var typesInferrer = typesTask.typesInferrer;
+    var element = findElement(compiler, "foo");
+    var mask = typesInferrer.getReturnTypeOfElement(element);
+    var falseType = new ValueTypeMask(typesTask.boolType, false);
+    // 'foo' should always return false
+    Expect.equals(falseType, mask);
+    // the argument to 'bar' is always false
+    var bar = findElement(compiler, "bar");
+    var barArg = bar.parameters.first;
+    var barArgMask = typesInferrer.getTypeOfElement(barArg);
+    Expect.equals(falseType, barArgMask);
+    var barCode = compiler.backend.getGeneratedCode(bar);
+    Expect.isTrue(barCode.contains('"bbb"'));
+    Expect.isFalse(barCode.contains('"aaa"'));
+  });
+}
+
+const String TEST2 = r"""
+foo(x) {
+  if (x > 3) return true;
+  return false;
+}
+
+bar(x) {
+  if (x) {
+    print("aaa");
+  } else {
+    print("bbb");
+  }
+}
+
+main() {
+  bar(foo(5));
+  bar(foo(6));
+}
+""";
+
+Future runTest2() {
+  Uri uri = new Uri(scheme: 'source');
+  var compiler = compilerFor(TEST2, uri);
+  return compiler.runCompiler(uri).then((_) {
+    var typesTask = compiler.typesTask;
+    var typesInferrer = typesTask.typesInferrer;
+    var element = findElement(compiler, "foo");
+    var mask = typesInferrer.getReturnTypeOfElement(element);
+    // Can't infer value for foo's return type, it could be either true or false
+    Expect.identical(typesTask.boolType, mask);
+    var bar = findElement(compiler, "bar");
+    var barArg = bar.parameters.first;
+    var barArgMask = typesInferrer.getTypeOfElement(barArg);
+    // The argument to bar should have the same type as the return type of foo
+    Expect.identical(typesTask.boolType, barArgMask);
+    var barCode = compiler.backend.getGeneratedCode(bar);
+    Expect.isTrue(barCode.contains('"bbb"'));
+    // Still must output the print for "aaa"
+    Expect.isTrue(barCode.contains('"aaa"'));
+  });
+}
+
+main() {
+  asyncStart();
+  runTest1().then((_) {
+    return runTest2();
+  }).whenComplete(asyncEnd);
+}