src/stdio_redirection_test.cc

// Copyright 2023 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "stdio_redirection.h"

#include "async_loop.h"
#include "test.h"

TEST(StdioAsyncStringRedirector, Test) {
  auto async_loop = AsyncLoop::CreateLocal();
  std::string result;
  {
    StdioAsyncStringRedirector async_stdout(*async_loop, stdout);
    // IMPORTANT: Do not include \n in the input because fprintf()
    // may or may not translate that into \r\n depending on too many
    // factors to handle here.
    fprintf(stdout, "Hello!");
    EXPECT_TRUE(async_stdout.WaitForResult(&result));
  }
  EXPECT_EQ(result, "Hello!");
}

TEST(StdioAsyncStringRedirector, TestWithTimeout) {
  auto async_loop = AsyncLoop::CreateLocal();
  std::string result;
  bool ret;
  IpcHandle duplicate_stdout_fd;
  {
    StdioAsyncStringRedirector async_stdout(*async_loop, stdout);
    fprintf(stdout, "Hello!");
    fflush(stdout);

    // Duplicate stdout handle, which will prevent the internal
    // pipe to be closed properly by WaitForResult() which will
    // timeout after 10ms.
    duplicate_stdout_fd = IpcHandle::CloneFromStdio(stdout);
    ret = async_stdout.WaitForResult(&result, 10LL);
  }
  EXPECT_FALSE(ret);
  EXPECT_TRUE(duplicate_stdout_fd);
  EXPECT_EQ(result, "Hello!");
}