Mojo EDK: Introduce MojoQueryHandleSignalsState API

mojo/public/cpp/system/tests/handle_signals_state_unittest.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "mojo/public/cpp/system/handle_signals_state.h"
+
+#include "mojo/public/c/system/types.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mojo {
+namespace {
+
+using HandleSignalsStateTest = testing::Test;
+
+TEST_F(HandleSignalsStateTest, SanityCheck) {
+  // There's not much to test here. Just a quick sanity check to make sure the
+  // code compiles and the helper methods do what they're supposed to do.
+
+  HandleSignalsState empty_signals(MOJO_HANDLE_SIGNAL_NONE,
+                                   MOJO_HANDLE_SIGNAL_NONE);
+  EXPECT_FALSE(empty_signals.readable());
+  EXPECT_FALSE(empty_signals.writable());
+  EXPECT_FALSE(empty_signals.peer_closed());
+  EXPECT_TRUE(empty_signals.never_readable());
+  EXPECT_TRUE(empty_signals.never_writable());
+  EXPECT_TRUE(empty_signals.never_peer_closed());
+
+  HandleSignalsState all_signals(
+      MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE |
+          MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+      MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE |
+          MOJO_HANDLE_SIGNAL_PEER_CLOSED);
+  EXPECT_TRUE(all_signals.readable());
+  EXPECT_TRUE(all_signals.writable());
+  EXPECT_TRUE(all_signals.peer_closed());
+  EXPECT_FALSE(all_signals.never_readable());
+  EXPECT_FALSE(all_signals.never_writable());
+  EXPECT_FALSE(all_signals.never_peer_closed());
+}
+
+}  // namespace
+}  // namespace mojo