git-pm-version-delta.pl

#!/usr/bin/env perl
use 5.010;
use strict;
use warnings;
use autodie;
use Git::Wrapper;
use File::Find::Rule ();
use File::Find::Rule::Perl ();

my $tag = shift
  or die "Usage: $0 <tag>\n";

my $git = Git::Wrapper->new(".");

my @files = File::Find::Rule->perl_file->in("lib");

for my $file ( @files ) {
  my @diff = $git->diff( "$tag", "--", $file );
  next unless @diff;
  say "$file: " . scalar @diff . " diff lines";
  my @version_lines = map { "    $_" } grep { /\$(?:(?:\w+::)+)*VERSION\s*=\s*/ } @diff;
  if ( @version_lines ) {
    say for @version_lines;
  }
  else {
    say "  *** NEEDS VERSION BUMP! ***";
  }
}