PdfSpec includes rspec matchers to compare the appearance of PDF files. This is obviously most useful when you need to verify that you can produce a PDF that looks identical to a sample PDF file.
This library depends on the rmagick ruby gem.
brew install imagemagick
brew install ghostscript
sudo port install ImageMagick
The following was tested on Ubuntu 11.10, 12.04, and 20.04.
sudo apt-get install libmagickwand-dev
On Ubuntu 20.04 and later, you may run into the following error:
Magick::ImageMagickError:
attempt to perform an operation not allowed by the security policy `PDF' @ error/constitute.c/IsCoderAuthorized/408
To resolve this, edit /etc/ImageMagick-6/policy.xml. Change <policy domain="coder" rights="none" pattern="PDF" /> to <policy domain="coder" rights="read|write" pattern="PDF" />.
If that doesn't help, change <!-- <policy domain="module" rights="none" pattern="{PS,PDF,XPS}" /> --> to <policy domain="module" rights="read|write" pattern="{PS,PDF,XPS}" />.
# Install libmagickwand
To use the matchers in your tests, simple include the Matchers module into RSpec:
RSpec.configure do |config|
config.include(PdfSpec::Matchers)
end
Or include it in certain tests:
describe "Testing PDFs" do
include PdfSpec::Matchers
it "should match..."; end
end
Matchers contains the have_same_pdf_appearance_as expectation which will render
out PDF files to pixel buffers in memory and then compare them pixel by pixel.
it "should be the same PDF" do
source_pdf = File.read("path/to/source")
expected_pdf = File.read("path/to/expected")
source.should have_same_pdf_appearance_as(expected_pdf)
end