whitelist options accepted by pandoc

Gemfile.lock

@@ -1,14 +1,12 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    json (1.8.3)
     metaclass (0.0.4)
-    minitest (5.8.4)
+    minitest (5.8.5)
     mocha (1.1.0)
       metaclass (~> 0.0.1)
-    rake (11.1.2)
-    rdoc (4.2.2)
-      json (~> 1.4)
+    rake (12.0.0)
+    rdoc (5.0.0)
 
 PLATFORMS
   ruby
@@ -20,4 +18,4 @@ DEPENDENCIES
   rdoc
 
 BUNDLED WITH
-   1.12.2
+   1.12.5

README.md

@@ -121,6 +121,10 @@ the correct header and footer are added.
 PandocRuby.new("# Some title", :standalone).to_rtf
 ```
 
+My default only whitelisted options (those known to Pandoc) are passed on to
+Pandoc. You can send all options to Pandoc by using the `:ignore_whitelist`
+option.
+
 ## Note on Patches/Pull Requests
 
 * Fork the project.

lib/pandoc-ruby.rb

@@ -57,6 +57,28 @@ class PandocRuby
   # All of the available Writers.
   WRITERS = STRING_WRITERS.merge(BINARY_WRITERS)
 
+  # Options understood by pandoc, taken from http://pandoc.org/MANUAL.html.
+  # Ignore all other options passed to pandoc, unless overriden.
+  AVAILABLE_OPTIONS = Set.new %w(from read to write output data-dir strict
+    parse-raw smart old-dashes base-header-level indented-code-classes filter
+    normalize preserve-tabs tab-stop track-changes file-scope extract-media
+    standalone template metadata variable print-default-template
+    print-default-data-file no-wrap wrap columns toc table-of-contents toc-depth
+    no-highlight highlight-style include-in-header include-before-body
+    include-after-body self-contained offline html5 html-q-tags ascii
+    reference-links reference-location atx-headers chapters top-level-division
+    number-sections number-offsetS no-tex-ligatures listings incremental
+    slide-level section-divs default-image-extension email-obfuscation id-prefix
+    title-prefix css reference-odt reference-docx epub-stylesheet
+    epub-cover-image epub-metadata epub-embed-font epub-chapter-level
+    latex-engine latex-engine-opt bibliography csl citation-abbreviations natbib
+    biblatex latexmathml asciimathml mathml mimetex webtex jsmath mathjax katex
+    katex-stylesheet gladtex trace dump-args ignore-args verbose bash-completion
+    list-input-formats list-output-formats list-extensions
+    list-highlight-languages list-highlight-styles)
+  ALIAS_OPTIONS = Set.new %w(f r t w o R S F p s M V D H B A 5 N i T c m)
+  ALLOWED_OPTIONS = AVAILABLE_OPTIONS + ALIAS_OPTIONS
+
   # To use run the pandoc command with a custom executable path, the path
   # to the pandoc executable can be set here.
   def self.pandoc_path=(path)
@@ -243,11 +265,13 @@ def prepare_options(opts = [])
     # Takes a flag and optional argument, uses it to set any relevant options
     # used by the library, and returns string with the option formatted as a
     # command line options. If the option has an argument, it is also included.
+    # Only whitelisted options are sent to pandoc, unless overridden.
     def create_option(flag, argument = nil)
       return '' unless flag
       flag = flag.to_s
       set_pandoc_ruby_options(flag, argument)
-      return '' if flag == 'timeout' # pandoc doesn't accept timeouts yet
+      return '' unless ALLOWED_OPTIONS.include?(flag.gsub('_', '-')) ||
+                       @options.find { |o| o == :ignore_whitelist }
       if !argument.nil?
         "#{format_flag(flag)} #{argument}"
       else

test/test_pandoc_ruby.rb

@@ -92,9 +92,15 @@
     assert converter.convert
   end
 
+  it 'ignores options not whitelisted' do
+    converter = PandocRuby.new('# hello', 'badopt')
+    converter.expects(:execute).with('pandoc').returns(true)
+    assert converter.convert
+  end
+
   it 'raises RuntimeError from pandoc executable error' do
     assert_raises(RuntimeError) do
-      PandocRuby.new('# hello', 'badopt').to_html5
+      PandocRuby.new('# hello', 'badopt', :ignore_whitelist).to_html5
     end
   end