Add test cases involving random data

tests.py

@@ -2,6 +2,7 @@
 from os import stat
 from os.path import exists, dirname, realpath, join
 from stat import S_ISFIFO
+from secrets import token_urlsafe
 
 import pytest
 
@@ -32,11 +33,14 @@ def test_pipes_isfifo(pipe_io):
 
 @pytest.mark.parametrize(
     'test_data', [
-        'cats',
-        'cheese',
+        'Cats and cheese',
         'You ever wonder why we are here?',
         'Lorem ipsum dolor sit amet',
-        'You always have a plan, Dutch!'
+        'You always have a plan, Dutch!',
+        token_urlsafe(32),
+        token_urlsafe(32),
+        token_urlsafe(32),
+        token_urlsafe(32)
     ]
 )
 def test_echo_server(pipe_io, test_data):