dart2dart: Logical operators and related rewrite rules in dart_tree.

tests/language/if_flatten2_test.dart

Index: tests/language/if_flatten2_test.dart
diff --git a/tests/language/if_flatten2_test.dart b/tests/language/if_flatten2_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..0cc11922641ff6cf2fffbb777b6effb56406bed9
--- /dev/null
+++ b/tests/language/if_flatten2_test.dart
@@ -0,0 +1,72 @@
+// Copyright (c) 2014, 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';
+
+check_true_true(x, y) {
+  if (x) {
+    if (y) {
+      return true;
+    }
+  }
+  return false;
+}
+
+check_false_true(x, y) {
+  if (x) {
+
+  } else {
+    if (y) {
+      return true;
+    }
+  }
+  return false;
+}
+
+check_true_false(x, y) {
+  if (x) {
+    if (y) {
+
+    } else {
+      return true;
+    }
+  }
+  return false;
+}
+
+check_false_false(x, y) {
+  if (x) {
+
+  } else {
+    if (y) {
+
+    } else {
+      return true;
+    }
+  }
+  return false;
+}
+
+
+main() {
+  Expect.equals(true, check_true_true(true, true));
+  Expect.equals(false, check_true_true(true, false));
+  Expect.equals(false, check_true_true(false, true));
+  Expect.equals(false, check_true_true(false, false));
+
+  Expect.equals(false, check_true_false(true, true));
+  Expect.equals(true, check_true_false(true, false));
+  Expect.equals(false, check_true_false(false, true));
+  Expect.equals(false, check_true_false(false, false));
+
+  Expect.equals(false, check_false_true(true, true));
+  Expect.equals(false, check_false_true(true, false));
+  Expect.equals(true, check_false_true(false, true));
+  Expect.equals(false, check_false_true(false, false));
+
+  Expect.equals(false, check_false_false(true, true));
+  Expect.equals(false, check_false_false(true, false));
+  Expect.equals(false, check_false_false(false, true));
+  Expect.equals(true, check_false_false(false, false));
+}