Start checking PRs with perlcritic

.perlcriticrc

@@ -0,0 +1,4 @@
+theme = community
+
+# 5 is the least complainy, 1 is the most complainy
+severity = 5

README.md

@@ -106,17 +106,33 @@ conflicts with services that might be running on your host, hydra and postgress
 Note that this is only ever meant as an ad-hoc way of executing Hydra during development. Please make use of the
 NixOS module for actually running Hydra in production.
 
-### Running Tests
+### Checking your patches
 
-After making your changes, verify the test suite still passes. After following the steps in [Development Environment](#development-environment), run:
+After making your changes, verify the test suite passes and perlcritic is still happy.
+
+Start by following the steps in [Development Environment](#development-environment).
+
+Then, you can run the tests and the perlcritic linter together with:
+
+```console
+$ nix-shell
+$ make check
+```
+
+You can run a single test with:
 
 ```
 $ nix-shell
-$ make check
-$ # Or, to run a single test, use:
 $ yath test ./t/foo/bar.t
 ```
 
+And you can run just perlcritic with:
+
+```
+$ nix-shell
+$ make perlcritic
+```
+
 ### JSON API
 
 You can also interface with Hydra through a JSON API. The API is defined in [hydra-api.yaml](./hydra-api.yaml) and you can test and explore via the [swagger editor](https://editor.swagger.io/?url=https://raw.githubusercontent.com/NixOS/hydra/master/hydra-api.yaml)

t/Makefile.am

@@ -23,6 +23,7 @@ EXTRA_DIST = \
   $(TESTS)
 
 TESTS = \
+  perlcritic.pl \
   test.pl
 
 check_SCRIPTS = repos

t/perlcritic.pl

@@ -0,0 +1,13 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use Cwd 'abs_path';
+use File::Basename;
+
+my $dirname = abs_path(dirname(__FILE__) . "/..");
+
+print STDERR "Executing perlcritic against $dirname\n";
+chdir($dirname) or die "Failed to enter $dirname\n";
+
+exec("perlcritic", ".") or die "Failed to execute perlcritic.";