On Sat, 25 Apr 2020 18:41:37 +1200
DL Neil <pythonl...@danceswithmice.info> wrote:
> On 25/04/20 5:16 PM, Manfred Lotz wrote:
> > On Fri, 24 Apr 2020 19:12:39 -0300
> > Cholo Lennon <chololen...@hotmail.com> wrote:
> >
> >> On 24/4/20 15:40, Manfred Lotz wrote:
> >>> I have a command like application which checks a directory tree
> >>> for certain things. If there are errors then messages will be
> >>> written to stdout.
> >>>
> >>> How to test this in the best way?
> >>>
> >>> One idea was for the error situations to write messages to files
> >>> and then later when running the tests to compare the error
> >>> messages output to the previously saved output.
> >>>
> >>> Is there anything better?
> >>>
> >>>
> >>
> >> Maybe I am wrong because I don't understand your scenario: If your
> >> application is like a command, it has to return an error code to
> >> the system, a distinct number for each error condition. The error
> >> code is easier to test than the stdout/stderr.
> >>
> >
> > Yes, a different error code for each condition is good to test.
> > However, I need to test as well the correct file name and other
> > values belonging to a certain error condition.
>
> It is frustrating to be shown only part of the information, and later
> be told our efforts aren't good-enough.
I found the tips I got here quite good. Actually, each time when I had
a questions here I got competent answers.
> How about respecting our
> (donated) time, and posting some sample code that shows exactly
> what/where the problem lies?
>
Sorry, perhaps I was too lazy to explain. Hope the following
explanation isn't too bad.
What I do here specifically is to check directory trees' file objects
for user and group ownerships as well as permissions according to a
given policy. There is a general policy and there could be exceptions
which specify a specific policy for a certain file.
The policy file is a JSON file and could have different categories.
Each category defines a policy for a certain directory tree. Comand
line args could overwrite directory names, as well as user and group.
Or if for example a directory is not specified in the JSON file I am
required to specify it via command line. Otherwise no check can take
place.
Here an example of a simple json file:
default":
{
"match_perms": "644",
"match_permsd": "755",
"match_permsx": "755",
"owner": "manfred",
"group": "manfred"
}
}
another simple example:
{
"default":
{
"have_all_permsx" : "555",
"have_all_perms" : "444",
"have_all_permsd" : "555",
"owner": "manfred",
"group": "manfred"
}
}
class Category contains a policy.
Here a simplified version of Category
class Category:
def __init__(self, cat, jsoncat, dirdict, ownerdict, groupdict):
self.cat = cat
self.jsoncat = jsoncat
self.keep_fs = jsoncat.get('keep_fs')
self.dir = jsoncat.get('dir')
if dirdict.get(cat):
self.dir = os.path.realpath(dirdict[cat])
self.policy = Policy(jsoncat, ownerdict, groupdict)
def check(self, fpath):
self.policy.check(fpath)
It is important to note that ownerdict and groupdict are overwrites
from the command line, and could be empty if nothing was
specified.
In my main routine I do this
...
for cat in cats:
...
for d in scantree(cat.dir):
# if `keep_fs` was specified then we must
# make sure the file is on the same device
if cat.keep_fs and devid != get_devid(d.path):
continue
cat.check(d)
...
class Policy contains required user and group owners and a
list of permission objects for files, for executable files and for
directories.
Those permissions are described like this
class BasePerms:
def __init__(self, perms: str):
"""Create an object holding a permission which is octal"""
self.perms = int(perms, 8)
class MatchPerms(BasePerms):
def check(self, fpath: str, mode: int):
mode = mode & 0o7777
if mode != self.perms:
print("%s perms differ, should have %s has %s" % (fpath,
oct(self.perms), oct(mode)))
class HaveAllPerms(BasePerms):
def check(self, fpath: str, mode: int):
mode = mode & 0o7777
if (mode & self.perms) != self.perms:
print("%s: perms differ, should have all of %s has %s" % (fpath,
oct(self.perms), oct(mode)))
After getting some ideas here I want to change my code to return an
error object in check() instead of doing a print(). Or return None
if all is ok.
Then the error object could have a print-like method and a compare
method so that later on when doing a test I could compare two error
objects. Perhaps I can combine it with callback. I have to play with
these things.
--
Manfred
--
https://mail.python.org/mailman/listinfo/python-list
