Add a Mojo example apptest that runs in mojo_shell.

mojo/examples/test/example_unittest.cc

Index: mojo/examples/test/example_unittest.cc
diff --git a/mojo/examples/test/example_unittest.cc b/mojo/examples/test/example_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e894525a5ac926c07c6b6b17931b52377c74d944
--- /dev/null
+++ b/mojo/examples/test/example_unittest.cc
@@ -0,0 +1,123 @@
+// Copyright 2014 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.
+
+// TODO(msw): Use mojo_main_chromium.cc mojo_environment_chromium for base/ 
+//            not mojo_main_standalone.cc and mojo_environment_standalone ??? 
+//            (a mojo_main_chromium app can test standalone services and apps) 
+
+#include "mojo/examples/test/example_service.mojom.h"
+#include "mojo/examples/test/example_service_impl.h"
+#include "mojo/public/cpp/application/application_delegate.h"
+#include "mojo/public/cpp/application/application_impl.h"
+#include "mojo/public/cpp/bindings/callback.h"
+#include "mojo/public/cpp/environment/environment.h"
+#include "mojo/public/cpp/system/macros.h"
+#include "mojo/public/cpp/utility/run_loop.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+// TODO(msw): Avoid globals ... 
+mojo::ApplicationImpl* g_application_impl_hack = NULL;
+mojo::RunLoop* g_run_loop_hack = NULL;
+
+}  // namespace
+
+namespace mojo {
+
+namespace {
+
+// TODO(msw): Split example_service_unittest and example_client_unittest ??? 
+class ExampleClientImpl : public InterfaceImpl<ExampleClient> {
+ public:
+  explicit ExampleClientImpl() : last_pong_value_(0) {}
+  virtual ~ExampleClientImpl() {}
+  int16_t last_pong_value() const { return last_pong_value_; }
+
+ protected:
+  // InterfaceImpl<ExampleClient> overrides.
+  virtual void Pong(uint16_t pong_value) MOJO_OVERRIDE {
+    last_pong_value_ = pong_value;
+    g_run_loop_hack->Quit();
+  }
+
+ private:
+  int16_t last_pong_value_;
+  MOJO_DISALLOW_COPY_AND_ASSIGN(ExampleClientImpl);
+};
+
+// TODO(msw): Split example_service_unittest and example_client_unittest ??? 
+class ExampleServiceTest : public testing::Test {
+ public:
+  ExampleServiceTest() {
+    g_application_impl_hack->ConnectToService("mojo:mojo_example_service",
+                                              &example_service_);
+    example_service_.set_client(&example_client_);
+  }
+
+  virtual ~ExampleServiceTest() MOJO_OVERRIDE {
+    example_service_.reset();
+  }
+
+ protected:
+  ExampleServicePtr example_service_;
+  ExampleClientImpl example_client_;
+
+ private:
+  MOJO_DISALLOW_COPY_AND_ASSIGN(ExampleServiceTest);
+};
+
+TEST_F(ExampleServiceTest, Ping) {
+  EXPECT_EQ(0, example_client_.last_pong_value());
+  example_service_->Ping(1);
+  g_run_loop_hack->Run();
+  EXPECT_EQ(1, example_client_.last_pong_value());
+}
+
+// TODO(msw): Attempt mojo::Callbacks without base::Bind ??? 
+template <typename T>
+struct SetAndQuit : public Callback<void()>::Runnable {
+  SetAndQuit(T* val, T result) : val_(val), result_(result) {}
+  virtual ~SetAndQuit() {}
+  virtual void Run() const MOJO_OVERRIDE{
+    *val_ = result_;
+    g_run_loop_hack->Quit();
+  }
+  T* val_;
+  T result_;
+};
+
+TEST_F(ExampleServiceTest, RunCallback) {
+  bool was_run = false;
+  example_service_->RunCallback(SetAndQuit<bool>(&was_run, true));
+  g_run_loop_hack->Run();
+  EXPECT_TRUE(was_run);
+}
+
+}  // namespace
+
+}  // namespace mojo
+
+extern "C" APPLICATION_EXPORT MojoResult CDECL MojoMain(
+    MojoHandle shell_handle) {
+  mojo::Environment env;
+  mojo::RunLoop loop;
+  g_run_loop_hack = &loop;
+
+  // TODO(msw): Use mojo::ApplicationDelegate::Create() ??? 
+  //            Add a TestApplicationDelegate helper? What would it offer ??? 
+  mojo::ApplicationDelegate delegate;

[Ben Goodger (Google), 2014/07/30 16:53:18]

I think you can implement an ApplicationDelegate in this file and move all the
subsequent gtest stuff to Initialize().

[msw, 2014/08/06 22:34:40]

After moving the client service impl and application delegate to separate files,
I don't think that's the right way to go. Additionally, calling RUN_ALL_TESTS
from ExampleClientApplication::Initialize yields SEH exceptions in the tests;
perhaps Initialize is to early to actually run the tests? I can dig deeper or
post a RunAllTests task from Initialize and spin the message loop from MojoMain,
if you prefer that (patch set 7):
https://codereview.chromium.org/399653004/diff/220001/mojo/examples/test/exam...

+  mojo::ApplicationImpl app(&delegate);
+  app.BindShell(shell_handle);
+  g_application_impl_hack = &app;
+
+  // TODO(msw): Get actual commandline arguments ... 
+  int argc = 0;
+  char** argv = NULL;
+  testing::InitGoogleTest(&argc, argv);
+
+  // TODO(msw): g_run_loop_hack->Quit(); or kill some KeepAlive ??? 
+  //            See http://crbug.com/394477 and http://crbug.com/392685 
+  return RUN_ALL_TESTS() == 0 ? MOJO_RESULT_OK : MOJO_RESULT_UNKNOWN;

[Ben Goodger (Google), 2014/07/30 16:53:18]

lifetime issues being handled by timsteele it seems.

You can just return MOJO_RESULT_OK for the time being.

[msw, 2014/08/06 22:34:40]

Done.

+}