PdfMatcher

A gem to compare two PDFs and output the differences using diff-pdf.

Prerequisites

diff-pdf Required

This gem requires diff-pdf. See the README.md for how to install it.

Note that you can install it with hidakatsuya/setup-diff-pdf in GitHub Action.

Supported Ruby Versions

3.0, 3.1, 3.2, 3.3

Installation

Add this line to your application's Gemfile:

gem 'pdf_matcher'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install pdf_matcher

Usage

PdfMatcher.match?

Returns true if the PDFs match, false otherwise.

PdfMatcher.match?(pdf_a_data, pdf_b_data)
PdfMatcher.match?('/path/to/a.pdf', '/path/to/b.pdf')
PdfMatcher.match?(Pathname('/path/to/a.pdf'), Pathname('/path/to/b.pdf'))

output_diff option:

If the PDFs do not match, a difference PDF file will be generated at the path specified.

PdfMatcher.match?(pdf_a_data, pdf_b_data, output_diff: '/path/to/diff.pdf')

diff_pdf_opts option:

The specified values will be set as options for the diff-pdf command.

PdfMatcher.match?(pdf_a_data, pdf_b_data, diff_pdf_opts: ['--mark-differences', '--dpi=600'])

PdfMatcher.match

Returns the PDF match result as a PdfMatcher::MatchResult object.

result = PdfMatcher.match(
  pdf_a, pdf_b,
  output_diff: nil,
  diff_pdf_opts: nil
)

result.matched? #=> boolean

# Returns nil if pdf data is passed, otherwise returns path as Pathname.
result.pdf1_path #=> Pathname or nil
result.pdf2_path #=> Pathname or nil

result.pdf1_data #=> "%PDF-..."
result.pdf2_data #=> "%PDF-..."

# Returns nil if the output_diff parameter is nil or the PDFs do not match.
result.diff_pdf_path #=> Pathname or nil
result.diff_pdf_data #=> "%PDF-..." or nil

Configuring the default options for the diff-pdf command

PdfMatcher.config.diff_pdf_opts = %w(
  --mark-differences
  --channel-tolerance=40
)

See diff-pdf --help for available options of the diff-pdf.

Use in Testing Frameworks

Try pdf_matcher-testing gem.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/hidakatsuya/pdf_matcher. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

Testing

$ bundle exec rake test

However, this gem requires diff-pdf. You can install it locally or use a docker container.

$ docker pull ghcr.io/hidakatsuya/ruby-with-diff-pdf:3.2
$ docker run -v $PWD:/src:cached -it ghcr.io/hidakatsuya/ruby-with-diff-pdf bash

> src# bundle install
> src# bundle exec rake test

Or, you can run tests instantlly like this:

$ docker run --rm -v $PWD:/src -it ghcr.io/hidakatsuya/ruby-with-diff-pdf bash -c "bundle install && bundle exec rake test"

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the PdfMatcher project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.