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package Code::TidyAll::Plugin::YAMLFrontMatter;
use strict;
use warnings;
use namespace::autoclean;
our $VERSION = '1.000003';
use Moo;
use Encode qw( decode encode FB_CROAK );
use Path::Tiny qw( path );
use Try::Tiny qw( catch try );
use YAML::PP 0.006 ();
extends 'Code::TidyAll::Plugin';
# This regular expression is based on the regex
# \A(---\s*\n.*?\n?)^((---|\.\.\.)\s*$\n?) (with the m flag)
# from the Jekyll source code here:
# https://github.com/jekyll/jekyll/blob/c7d98cae2652b2df7ebd3c60b4f8c87950760e47/lib/jekyll/document.rb#L13
# note - The 'm' modifier in ruby is essentially the same as 's' in Perl
# so we need to enable the 's' modifier not 'm'
# - Ruby essentially always treats '^' and '$' the way Perl does when the
# 'm' modifier is enabled, so we need to turn that on too
# - We need to enable the 'x' modifier and space things out so that
# Perl treats '$\n' as '$' and '\n' and not the variable '$\' and 'n'
my $YAML_REGEX = qr{
\A
# the starting ---, and anything up until...
(---\s*\n.*?\n?)
# ...the first --- or ... on their own line
^ (?:---|\.\.\.) \s* $ \n?
}msx;
has encoding => (
is => 'ro',
# By default Jekyll 2.0 and later defaults to utf-8, so this seems
# like a sensible default for us
default => 'UTF-8',
);
has required_top_level_keys => (
is => 'ro',
default => q{},
);
has _req_keys_hash => ( is => 'lazy' );
sub _build__req_keys_hash {
my $self = shift;
return +{
# note use of magical split on space to do automatic trimming
map { $_ => 1 } split q{ }, $self->required_top_level_keys
};
}
sub validate_file {
my ( $self, $filename ) = @_;
my $src = path($filename)->slurp_raw;
# YAML::PP always expects things to be in UTF-8 bytes
my $encoding = $self->encoding;
try {
$src = decode( $encoding, $src, FB_CROAK );
$src = encode( 'UTF-8', $src, FB_CROAK );
}
catch {
die "File does not match encoding '$encoding': $_";
};
# is there a BOM? There's not meant to be a BOM!
if ( $src =~ /\A\x{EF}\x{BB}\x{BF}/ ) {
die "Starting document with UTF-8 BOM is not allowed\n";
}
# match the YAML front matter.
my $yaml;
unless ( ($yaml) = $src =~ $YAML_REGEX ) {
die "'$filename' does not start with valid YAML Front Matter\n";
}
# parse the YAML front matter.
my $ds = try {
my $yp = YAML::PP->new(
# Insist on YAML 1.1. Jekyl uses SafeYAML to parse YAML
# which will either use Syck (via "YAML") or LibYAML
# (via "Psych") to parse the YAML, so what YAML it can
# use is a matter of debate. However, since this module
# is a linter, we can make up our own rules, and they are
# that you have to write your frontmatter only in the
# YAML 1.1 spec. Todo: Make this insist in the most
# compatible YAML (i.e. freak out if someone uses "y"
# instead of "true") if YAML::PP ever supports such
# an option.
schema => ['YAML1_1'],
# we do not want to create circular refs
cyclic_refs => 'fatal',
);
return $yp->load_string($yaml);
}
catch {
die "Problem parsing YAML: $_";
};
# check for required keys
my $errors = q{};
for ( sort keys %{ $self->_req_keys_hash } ) {
next if $ds->{$_};
$errors .= "Missing required YAML Front Matter key: '$_'\n";
}
die $errors if $errors;
return;
}
1;
# ABSTRACT: TidyAll plugin for validating YAML Front Matter
__END__
=pod
=encoding UTF-8
=head1 NAME
Code::TidyAll::Plugin::YAMLFrontMatter - TidyAll plugin for validating YAML Front Matter
=head1 VERSION
version 1.000003
=head1 SYNOPSIS
In your .tidyallrc file:
[YAMLFrontMatter]
select = **/*.md
required_top_level_keys = title layout
=head1 DESCRIPTION
This is a validator plugin for L<Code::TidyAll> that can be used to check
that files have valid YAML Front Matter, like Jekyll et al use.
It will complain if:
=over
=item There's no YAML Front Matter
=item The YAML Front Matter isn't valid YAML
=item There's a UTF-8 BOM at the start of the file
=item The file isn't encoded in the configured encoding (UTF-8 by default)
=item The YAML Front Matter is missing one or more configured top level keys
=item The YAML Front Matter contains circular references
=back
=head2 Options
=over
=item C<required_top_level_keys>
Keys that must be present at the top level of the YAML Front Matter.
=item C<encoding>
The encoding the file is in. Defaults to UTF-8 (just like Jekyll 2.0 and
later.)
=back
=head1 SEE ALSO
L<Jekyll's Front Matter Documentation|https://jekyllrb.com/docs/frontmatter/>
=head1 SUPPORT
Please report all issues with this code using the GitHub issue tracker at
L<https://github.com/maxmind/Code-TidyAll-Plugin-YAMLFrontMatter/issues>.
Bugs may be submitted through L<https://github.com/maxmind/Code-Tidyall-Plugin-YAMLFrontMatter/issues>.
=head1 AUTHOR
Mark Fowler <mfowler@maxmind.com>
=head1 CONTRIBUTORS
=for stopwords Dave Rolsky Greg Oschwald
=over 4
=item *
Dave Rolsky <autarch@urth.org>
=item *
Greg Oschwald <goschwald@maxmind.com>
=back
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2019 by MaxMind, Inc.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut
|
