… where I get out my virtual broom and sweep up cruft in my assigned distribution for this month’s edition of the CPAN Pull Request Challenge.
This month’s module: Mo
Mo: Perl Micro Objects
In this section I try to get a feeling for the state of the module, how up to date it is, how often people are contributing to it, how many other distributions are depending on it, how many bugs/issues it currently has, what the CPANTS kwalitee is, etc.
- last commit 7th of July 2016 (https://github.com/ingydotnet/mo-pm)
- latest release 7th of July 2016 (https://metacpan.org/release/Mo)
- 6 open issues in GitHub
- 3 open pull requests
- 0 reverse dependencies via metacpan
- 1 test failure on cpantesters: http://www.cpantesters.org/distro/M/Mo.html
- on OpenBSD; difficult from error report to see what actual problem was
- CPANTS report (http://cpants.cpanauthors.org/release/TINITA/Mo-0.40)
use_strictcore kwalitee metrics
Initial inspection of the source code
After forking the repo and cloning a local copy, let’s have a look at the project to see what build system it uses, if the test suite works and the tests pass, if it could do with a Travis-CI config file (or if present, if it can be updated).
- Travis config could be updated to more Perl versions
- there is no
META.jsonin the repository; looks like they’re automatically generated, since they’re in the dist
- needed to run
dzil authordeps --missing | cpanmin order to run
dzil testshowed that
dzil authordeps --missing | cpanmwas necessary on my box
dzil testgives an error with
t/author-test-version.t, although this could be PEBKAC
- some of the
Dist::Zillaplugins are deprecated and need to be replaced
@Filter/PkgVersionshows many warnings
The code gets “golfed” from
documented and fairly readable [code] … and [reduces] it to a single undecipherable line.
Hence, these warnings are simply an artefact of the golfing process.
Looking at the code coverage can give an indication of code quality. If the project is well covered, this means most changes made in pull requests can be made with some confidence that any problems will be caught by the test suite. If the code coverage is low, then this is something that one could address as a pull request (or set of pull requests).
In EUMM and
Build::Module projects, one simply needs to install
Devel::Cover and run
Dist::Zilla projects, one needs to install the
Dist::Zilla::App::Command::cover plugin, after which the code coverage can
be checked via:
In this distribution, the coverage is:
97.9% statement coverage; 92.9% total coverage.
Which is excellent coverage. Strangely enough,
dzil cover runs to
dzil test doesn’t (see error in author test version
podchecker searches through Perl source code for POD which
might not conform to the POD standard, and thus not necessarily be parseable
by all POD parsers. Fixing any issues found by
podchecker has the
positive effect of also removing any warnings noted in the project’s
documentation displayed on MetaCPAN.
podchecker gives the following errors and warnings:
This issue is fixed in PR#33.
Check for trailing whitespace
Some projects consider this a must, and will disallow commits to be submitted which contain trailing whitespace (the Linux kernel is an example project where trailing whitespace isn’t permitted). Other projects see whitespace cleanup as simply nit-picking. Either way one sees it personally, this could be a useful pull request to a project, so it’s worthwhile fixing and submitting; the worst that can happen is that the pull request is closed unmerged.
To look for files with trailing whitespace, run
git grep ' $'. It can be
helpful to load the files found directly into
There’s already a
Dist::Zilla plugin checking for this and the issue was
resolved in PR#33.
Perl::Critic will show up many
potential issues for Perl code. By simply running
perlcritic on the
t directories, one can get a further handle on the code’s quality.
These commands generate many warnings, however this is the kind of module
where one knowingly doesn’t use strictures and does various kinds of magic,
perlcritic isn’t as helpful as it usually is.
Links to websites can go out of date, so it’s a good idea to see if they need updating or removing. A quick grep finds all the links. After which, we just need to see which links need fixing, if any.
All links look good.
This probably also sits in the nit-picking category for some people, however, copyright dates (theoretically) need to be kept up to date. The appropriate copyright year is usually the year of the last release. However, if a release looks imminent, then the current year is likely to be the right candidate. Some distributions put the author’s email address on the same line as the copyright date, hence this needs to be checked as well.
Files missing current year in copyright
Here we do a case-insensitive grep over the source for the word “copyright”,
the line of which we check for the existence of a year (i.e. 4 digits), look
for the appropriate year and then clean up the grep results to get something
we can pass directly to
Files missing an email address in copyright
Didn’t bother to add a missing email address to the copyright statement since this didn’t seem to be the pattern in this distribution.
Spell check POD
Good documentation can be a wonder to read. Not everyone’s docs are awesome, however we can keep the error rate to a minimum. A quick spell check will pick up most typos that don’t need to be there and fixing them can help improve the quality of a project.
In general, we want to find all files containing POD and run a spell checker
aspell) over all files, fixing typos we come across as we go. Not
all projects require this much effort, however here’s a general-ish way to
look for and check all POD in a project:
Now look for
.bak file and check differences between it and the output
.txt file, the process looks roughly like this:
Then update the appropriate
.pod files as necessary.
POD spell checks ok.
Although CPANTS is the main kwalitee
reference, one can also run the kwalitee tests locally. One can use the
t/kwalitee.t test script from
http://codeaffe.de/cpan-pull-request-challenge/ for this purpose.
However, the script only uses
Test::Kwalitee which doesn’t cover as many
metrics as CPANTS.
set of metrics closer to that used on CPANTS, so replace the
call with simply
use Test::Kwalitee::Extra. More information about the
many options to
Test::Kwalitee::Extra can be found on the MetaCPAN page.
Run the kwalitee tests in an
distribution like so:
or, if the distribution uses
Not sure if the kwalitee tests are useful for this module. A lot of magic happens and as a result many of the standard rules are broken so that this can happen. Hence the quality checks don’t bring as much value for a module of this kind.
Unfortunately, there wasn’t any time this month to really dig into GitHub issues, hence none of the open issues were addressed as part of this month’s challenge.
There are no issues in RT.
Overview of the pull requests made
- Replace EOLTests with Test::EOL - https://github.com/ingydotnet/mo-pm/pull/33
- Replace deprecated dzil plugins - https://github.com/ingydotnet/mo-pm/pull/34
- Update copyright year - https://github.com/ingydotnet/mo-pm/pull/35
- merged! (after an update to correct the initial PR)
Although the patches were of a very trivial nature, they managed to get the dist closer to passing its tests on all Perl versions again on Travis; the upstream dependency (INGY bundle) needs to be updated on CPAN so that the tests can pass again.
Many thanks to TINITA, INGY, and DOLMEN for their feedback and quick responses in order to get these patches merged!