Simple test script for https://github.com/gettalong/hexapdf/issues/288

gistfile1.txt

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'

  gem 'hexapdf'
  gem 'matrix'
  gem 'rake'
  gem 'rspec'
end

class HexaPdfFiller
  def call(template, values, readonly:)
    doc = HexaPDF::Document.new(io: StringIO.new(template))
    doc.acro_form.each_field do |field|
      field.field_value = values.fetch(field.field_name)
    end

    doc.acro_form.flatten(create_appearances: true) if readonly

    output = StringIO.new
    doc.write(output, validate: false, optimize: false)
    output.string
  end
end

RSpec.describe HexaPdfFiller do
  let(:root) { Pathname(__dir__) }
  let(:tmp_dir) { root.join('tmp/') }

  before do
    FileUtils.mkdir_p(tmp_dir)
  end

  context 'when PDF template filled with hexapdf' do
    it 'keeps form field font in generated PDF' do
      filler = described_class.new

      result = filler.call(
        File.binread('textfield.pdf'), { 'bootstyp' => 'Bootstyp' }, readonly: false
      )

      write_file('hexapdf.pdf', result)
      open_file('hexapdf.pdf')
    end
  end

  context 'when PDF template filled and flatten with hexapdf' do
    it 'does not keep form field font in generated PDF' do
      filler = described_class.new
      result = filler.call(
        File.binread('textfield.pdf'), { 'bootstyp' => 'Bootstyp' }, readonly: true
      )

      write_file('hexapdf_flatten.pdf', result)
      open_file('hexapdf_flatten.pdf')
    end
  end

  def write_file(filename, content)
    FileUtils.rm_f(tmp_dir.join(filename))
    File.binwrite(tmp_dir.join(filename), content)
  end

  def open_file(filename)
    system "open #{(tmp_dir.join(filename))}"
  end
end