text: import os
  import sys
  from subprocess import TimeoutExpired, check_call
  
  import boto3
  import pytest
  from moto import mock_s3
  
  from megfile.errors import S3Exception
  from megfile.lib.s3_pipe_handler import S3PipeHandler
  from tests.test_s3 import s3_empty_client
  
  BUCKET = 'bucket'
  KEY = 'key'
  CONTENT = b'block0\n block1\n block2'
  
  
  @pytest.fixture
  def client(s3_empty_client):
      s3_empty_client.create_bucket(Bucket=BUCKET)
      return s3_empty_client
  
  
  def test_s3_pipe_handler_close(client):
      writer = S3PipeHandler(BUCKET, KEY, 'wb', s3_client=client)
      assert writer.closed is False
      writer.close()
      assert writer.closed is True
  
      reader = S3PipeHandler(BUCKET, KEY, 'rb', s3_client=client)
      assert reader.closed is False
      reader.close()
      assert reader.closed is True
  
  
  def test_s3_pipe_handler_read(client):
      client.put_object(Bucket=BUCKET, Key=KEY, Body=CONTENT)
  
      with S3PipeHandler(BUCKET, KEY, 'rb', s3_client=client) as reader:
          assert reader.name == 's3://bucket/key'
          assert reader.mode == 'rb'
          assert reader.readable() is True
          assert reader.writable() is False
          assert reader.tell() == 0
          assert reader.readline() == b'block0\n'
          assert reader.tell() == 7
          assert reader.read() == b' block1\n block2'
          assert reader.tell() == 22
          assert reader.read() == b''
  
  
  def test_s3_pipe_handler_write(client):
      with S3PipeHandler(BUCKET, KEY, 'wb', s3_client=client) as writer:
          assert writer.name == 's3://bucket/key'
          assert writer.mode == 'wb'
          assert writer.readable() is False
          assert writer.writable() is True
          writer.write(CONTENT)
          assert writer.tell() == 22
          writer.flush()
  
      content = client.get_object(Bucket=BUCKET, Key=KEY)['Body'].read()
      assert content == CONTENT
  
  
  def assert_no_timeout(filename, timeout=60):
      # TODO: 改为使用 multiprocessing.Process 方式实现
      # Process 与普通 Python 进程不同的是，退出时不会进 atexit 注册的 callback，导致目前已知的死锁问题并不会发生，因此这里使用了 subprocess 的实现作为 workaround
      path = os.path.join('tests', 'timeout', filename)
      check_call([sys.executable, path], env={'PYTHONPATH': '.'}, timeout=timeout)
  
  
  @pytest.mark.skip()
  def test_s3_pipe_handler_read_without_close():
      assert_no_timeout('s3_pipe_handler_read_without_close.py')
  
  
  @pytest.mark.skip()
  def test_s3_pipe_handler_write_without_close():
      assert_no_timeout('s3_pipe_handler_write_without_close.py')
  
  
  @pytest.fixture
  def error_client(s3_empty_client):
  
      def fake(*args, **kwargs):
          raise S3Exception()
  
      s3_empty_client.create_bucket(Bucket=BUCKET)
      s3_empty_client.download_fileobj = fake
      s3_empty_client.upload_fileobj = fake
  
      return s3_empty_client
  
  
  def test_s3_pipe_handler_error(error_client):
      with pytest.raises(S3Exception):
          with S3PipeHandler(BUCKET, KEY, 'wb', s3_client=error_client) as writer:
              writer._async_task.join()
              writer._raise_exception()
  
      with pytest.raises(S3Exception):
          with S3PipeHandler(BUCKET, KEY, 'rb', s3_client=error_client) as reader:
              reader._async_task.join()
              reader._raise_exception()
  