Issue #4116: Make infile and outfile parameters of flrender script from python-abp optional

tests/test_render_script.py

 # This file is part of Adblock Plus <https://adblockplus.org/>,
 # Copyright (C) 2006-present eyeo GmbH
 #
 # Adblock Plus is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 3 as
 # published by the Free Software Foundation.
 #
 # Adblock Plus is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
@@ skipping 76 matching lines @@
 @pytest.fixture
 def dstfile(tmpdir):
     """Destination file for saving rendered list."""
     return tmpdir.join('dst')
 
 
 def run_script(*args, **kw):
     """Run rendering script with given arguments and return its output."""
     cmd = ['flrender'] + list(args)
 
-    test_in = None
-    if 'test_in' in kw.keys():
-        test_in = kw.pop('test_in')

[Vasily Kuznetsov, 2018/07/13 17:41:04]

I just found that you can replace this and the two previous lines with:

    test_in = kw.pop('test_in', None)

[Tudor Avram, 2018/07/16 09:17:11]

Done.

+    test_in = kw.pop('test_in', None)
     if test_in is not None:
         test_in = test_in.encode('utf-8')
 
     proc = subprocess.Popen(cmd, stderr=subprocess.PIPE,
                             stdout=subprocess.PIPE, stdin=subprocess.PIPE,
                             **kw)
     stdout, stderr = proc.communicate(input=test_in)
     return proc.returncode, stderr.decode('utf-8'), stdout.decode('utf-8')
 
 
 @pytest.mark.parametrize('test_input, args', [
-    ('None', ("'simple.txt'", 'str(dstfile)')),

[Vasily Kuznetsov, 2018/07/13 17:41:04]

We iterate over the inner tuple, so according to our style guide [1] it should
be a list (same for the next line). Kind of minor but just to make it more...
neat :)

[1] https://adblockplus.org/coding-style#python

-    ('None', ("'simple.txt'",)),
-    ("rootdir.join('simple.txt').read()", ()),
+    ('None', ["'simple.txt'", 'str(dstfile)']),
+    ('None', ["'simple.txt'"]),
+    ("rootdir.join('simple.txt').read()", []),
 ])
 def test_render_no_includes(test_input, args, rootdir, dstfile):
-    _locals = locals()
-    test_input = eval(test_input, _locals)

[Vasily Kuznetsov, 2018/07/13 17:41:04]

But this eval doesn't need the _locals, right? It should be able to see them by
itself because it's in the right scope. Or am I wrong?

[Tudor Avram, 2018/07/16 09:17:11]

Done.

-    args = [eval(arg, _locals) for arg in args]

[Vasily Kuznetsov, 2018/07/13 17:41:04]

It seems that if you use map(eval, args) instead of the list comprehension, you
don't need to pass the locals. Unfortunately in Python3 the result of the map
can't be the argument of len() but you can still do list(map(eval, args)) and I
think it's still nicer.

[Tudor Avram, 2018/07/16 09:17:12]

Done.

-
+    test_input = eval(test_input)
+    args = list(map(eval, args))
     _, _, stdout = run_script(*args, cwd=str(rootdir), test_in=test_input)
 
     if len(args) > 1:
-        assert 'Ok' in dstfile.read()
+        output = dstfile.read()
     else:
-        assert 'Ok' in stdout
+        output = stdout
+
+    assert 'Ok' in output
+    assert '! Checksum:' in output
 
 
 def test_render_unicode(rootdir, dstfile):
     code, err, _ = run_script(str(rootdir.join('unicode.txt')), str(dstfile))
     assert '\u1234' in dstfile.read(mode='rb').decode('utf-8')
 
 
 def test_render_with_includes(rootdir, dstfile):
     run_script(str(rootdir.join('includer.txt')), str(dstfile),
                '-i', 'inc=' + str(rootdir.join('inc')))
@@ skipping 68 matching lines @@
 
 @pytest.mark.slowtest
 def test_failed_web_include(rootdir, dstfile, webserver_port):
     url = 'http://localhost:{}/missing.txt'.format(webserver_port)
     webinc = rootdir.join('webinc.txt')
     webinc.write('[Adblock]\n%include {}%'.format(url))
     code, err, _ = run_script(str(webinc), str(dstfile))
     assert code == 1
     assert err.startswith(
         "HTTP 404 Not found: '{0}' when including '{0}'".format(url))