Implement test case for large data

tests.py

@@ -1,5 +1,5 @@
 # pylint: disable=redefined-outer-name
-from os import stat
+from os import stat, urandom
 from os.path import exists, dirname, realpath, join
 from stat import S_ISFIFO
 from secrets import token_urlsafe
@@ -43,9 +43,26 @@ def test_pipes_isfifo(pipe_io):
         token_urlsafe(32)
     ]
 )
-def test_echo_server(pipe_io, test_data):
-    File(pipe_io.in_pipe).write(test_data)
-    assert File(pipe_io.out_pipe).read() == test_data
+def test_io(pipe_io, test_data):
+    File(pipe_io.in_pipe, string=True).write(test_data)
+    assert File(pipe_io.out_pipe, string=True).read() == test_data
+
+
+@pytest.mark.parametrize(
+    'test_data_size', [
+        1024,
+        1024*1024,
+        2*1024*1024,
+        4*1024*1024,
+        8*1024*1024,
+        16*1024*1024,
+        32*1024*1024
+    ]
+)
+def test_io_large_data(pipe_io, test_data_size):
+    random_data = urandom(test_data_size)
+    File(pipe_io.in_pipe).write(random_data)
+    assert File(pipe_io.out_pipe).read() == random_data
 
 
 def test_stop_removes_pipes(pipe_io):
@@ -55,13 +72,14 @@ def test_stop_removes_pipes(pipe_io):
 
 
 class File:
-    def __init__(self, path):
+    def __init__(self, path, string=False):
         self.path = path
+        self._filemode = '' if string else 'b'
 
     def write(self, what):
-        with open(self.path, 'w') as ofile:
+        with open(self.path, f'w{self._filemode}') as ofile:
             ofile.write(what)
 
     def read(self):
-        with open(self.path, 'r') as ifile:
+        with open(self.path, f'r{self._filemode}') as ifile:
             return ifile.read()