test suite is now testing pdf files content

Gemfile

@@ -62,6 +62,7 @@ group :test do
   gem 'webmock'
   gem 'vcr'
   gem 'byebug'
+  gem 'pdf-reader'
 end
 
 group :production do

Gemfile.lock

@@ -1,6 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    Ascii85 (1.0.2)
     aasm (4.1.0)
     actionmailer (4.2.5)
       actionpack (= 4.2.5)
@@ -41,6 +42,7 @@ GEM
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
     addressable (2.3.8)
+    afm (0.2.2)
     ansi (1.5.0)
     api-pagination (4.3.0)
     apipie-rails (0.3.6)
@@ -177,6 +179,7 @@ GEM
     has_secure_token (1.0.0)
       activerecord (>= 3.0)
     hashdiff (0.3.0)
+    hashery (2.1.2)
     hashie (3.4.2)
     highline (1.7.1)
     hike (1.2.3)
@@ -265,6 +268,12 @@ GEM
       httparty (~> 0.13)
     orm_adapter (0.5.0)
     pdf-core (0.5.1)
+    pdf-reader (1.4.0)
+      Ascii85 (~> 1.0.0)
+      afm (~> 0.2.1)
+      hashery (~> 2.0)
+      ruby-rc4
+      ttfunk
     pg (0.18.1)
     pkg-config (1.1.7)
     prawn (2.0.1)
@@ -335,6 +344,7 @@ GEM
       netrc (~> 0.7)
     rolify (4.0.0)
     ruby-progressbar (1.7.5)
+    ruby-rc4 (0.1.5)
     rubyzip (1.1.7)
     rufus-scheduler (3.0.9)
       tzinfo
@@ -488,6 +498,7 @@ DEPENDENCIES
   omniauth
   omniauth-oauth2
   openlab_ruby
+  pdf-reader
   pg
   prawn
   prawn-table
@@ -522,4 +533,4 @@ DEPENDENCIES
   webmock
 
 BUNDLED WITH
-   1.12.5
+   1.13.1

test/test_helper.rb

@@ -68,6 +68,31 @@ class ActiveSupport::TestCase
 
     assert File.exist?(invoice.file), 'Invoice PDF was not generated'
 
+    # now we check the file content
+    reader = PDF::Reader.new(invoice.file)
+    assert_equal 1, reader.page_count # single page invoice
+
+    ht_amount = invoice.total
+    page = reader.pages.first
+    lines = page.text.scan(/^.+/)
+    lines.each do |line|
+      # check that the numbers printed into the PDF file match the total stored in DB
+      if line.include? I18n.t('invoices.total_amount')
+        assert_equal invoice.total / 100.0, parse_amount_from_invoice_line(line), 'Invoice total rendered in the PDF file does not match'
+      end
+
+      # check that the VAT was correctly applied if it was configured
+      if line.include? I18n.t('invoices.including_total_excluding_taxes')
+        ht_amount = parse_amount_from_invoice_line(line)
+      end
+    end
+
+    if Setting.find_by(name: 'invoice_VAT-active').value == 'true'
+      vat_rate = Setting.find_by({name: 'invoice_VAT-rate'}).value.to_f
+      assert_equal (invoice.total / (vat_rate / 100 + 1)), ht_amount, 'Total excluding taxes rendered in the PDF file is not computed correct'
+    else
+      assert_equal invoice.total, ht_amount, 'VAT information was rendered in the PDF file despite that VAT was disabled'
+    end
     File.delete(invoice.file)
   end
 
@@ -89,6 +114,15 @@ class ActiveSupport::TestCase
       skip('Unable to test export which is not of the category "statistics"')
     end
   end
+
+  private
+
+  # Parse a line of text read from a PDF file and return the price included inside
+  # Line of text should be of form 'Label              $10.00'
+  # @returns {float}
+  def parse_amount_from_invoice_line line
+    line[line.rindex(' ')+1..-1].tr(I18n.t('number.currency.format.unit'), '').to_f
+  end
 end
 
 class ActionDispatch::IntegrationTest