Make Test::JMM, and use it in the tests, for extra funky stuff

 - $ENV{TRACK_MODULES}, to show me what my dependencies should be.
 - $ENV{TEST_JMM_HAS_C3} / _MOOSE ==0, to test the case where
   C3 or Moose isn't installed, without actually removing them.

t/01kwalitee.t

@@ -1,4 +1,6 @@
 #!/usr/bin/perl
+use lib 't/auxlib';
+use Test::JMM;
 use warnings;
 use strict;
 use Test::More;

t/02base.t

@@ -1,10 +1,11 @@
 #!/usr/bin/perl
+use lib 't/auxlib';
+use Test::JMM;
 use Test::More tests => 7;
 use Test::NoWarnings;
 use Test::Exception;
 use Test::Differences;
 use lib 't/lib';
-use lib 't/auxlib';
 
 use_ok('Pod::Inherit');
 
@@ -23,10 +24,8 @@ $pi_override->write_pod;
 ok(!-e 't/lib/OverrideSubClass.pod', "Doesn't produce unneeded pod for completely overridden base class");
 
 
-my ($skip_moose, $skip_classc3);
-eval "require Moose";
-
-if(!$@) {
+SKIP: {
+  skip "Moose not installed", 1 unless Test::JMM::has_moose;
   my $pi_moose = Pod::Inherit->new({ input_files => [ 't/auxlib/MooseSub.pm' ] });
   $pi_moose->write_pod;
   my $output = do { local (@ARGV, $/) = "t/auxlib/MooseSub.pod"; <> || 'NO OUTPUT' };
@@ -38,8 +37,8 @@ if(!$@) {
 #  ok(!-e 't/lib/MooseSub.pod', "Moose extends, existing POD");
 }
 
-eval "require Class::C3";
-if(!$@) {
+SKIP: {
+  skip "Class::C3 not installed", 1 unless Test::JMM::has_c3;
   my $pi_c3 = Pod::Inherit->new({ input_files => [ 't/auxlib/ClassC3Sub.pm' ] });
   $pi_c3->write_pod;
   eq_or_diff(

t/03pod-coverage.t

@@ -1,4 +1,6 @@
 #!/usr/bin/perl
+use lib 't/auxlib';
+use Test::JMM;
 use warnings;
 use strict;
 use Test::Pod::Coverage tests=>2;

t/03pod.t

@@ -1,4 +1,6 @@
 #!/usr/bin/perl
+use lib 't/auxlib';
+use Test::JMM;
 use warnings;
 use strict;
 use Test::More;

t/04files.t

@@ -1,5 +1,6 @@
 #!/usr/bin/perl
-
+use lib 't/auxlib';
+use Test::JMM;
 use Test::More 'no_plan';
 use Test::Differences;
 use Test::Pod;

t/05not_ours.t

@@ -1,4 +1,6 @@
 #!/usr/bin/perl
+use lib 't/auxlib';
+use Test::JMM;
 use warnings;
 use strict;
 use Pod::Inherit;

t/06dir.t

@@ -1,4 +1,6 @@
 #!/usr/bin/perl
+use lib 't/auxlib';
+use Test::JMM;
 use Test::More 'no_plan';
 use Test::Differences;
 use Test::Pod;

t/auxlib/Test/JMM.pm

@@ -0,0 +1,63 @@
+package Test::JMM;
+use warnings;
+use strict;
+use Module::CoreList;
+
+sub has_module {
+  # Modname is the actual name of the module: Class::C3.
+  # Shortname is what gets stuck in env vars: C3.
+  my ($modname, $shortname) = @_;
+  $shortname ||= $modname;
+  my $envvar = "TEST_JMM_HAS_".uc($shortname);
+  if (exists $ENV{$envvar}) {
+    return $ENV{$envvar};
+  }
+  if (eval "require $modname; 1") {
+    return 1;
+  } else {
+    return 0;
+  }
+}
+
+sub has_moose {
+  has_module('Moose');
+}
+
+sub has_c3 {
+  has_module('Class::C3', 'C3');
+}
+
+sub import {
+  if ($ENV{TRACK_MODULES}) {
+    print STDERR "# Doing Test::JMM::import\n";
+    unshift @INC, sub {
+      my ($self, $mod_as_filename) = @_;
+      my $modname = $mod_as_filename;
+      $modname =~ s!/!::!g;
+      $modname =~ s/\.pm$//;
+      my $filename = (caller)[1];
+      my $line = (caller)[2];
+      my $kind;
+      if ($filename =~ m/\bblib\b/) {
+        $kind = 'runtime';
+        #print STDERR "# In blib -- assuming runtime dependency of thing under test\n";
+      } elsif ($filename =~ m!^t\b!) {
+        $kind = 'test';
+        #print STDERR "# In t/ -- assuming testing dependency.\n";
+      } else {
+        return;
+      }
+      my $first_rel = Module::CoreList->first_release($modname);
+      if ($first_rel and $first_rel <= 5.006) {
+        print STDERR "# (Is core as of $first_rel)\n";
+        return ();
+      }
+      # print STDERR "# Attempting to find $mod_as_filename from $filename line $line for $kind\n";
+      print STDERR "# INC hook: $kind: $mod_as_filename for $kind\n";
+      return ();
+    }
+  }
+}
+
+1;
+