Merge pull request #6484 from opf/fix/pandoc-version

Detect pandoc functionality based on usage and output formats

[ci skip]

lib/open_project/text_formatting/formats/markdown/pandoc_wrapper.rb

@@ -0,0 +1,110 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is a project management system.
+# Copyright (C) 2012-2018 the OpenProject Foundation (OPF)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'open3'
+
+module OpenProject::TextFormatting::Formats
+  module Markdown
+    class PandocWrapper
+      def initialize; end
+
+      def execute!(stdin)
+        run_pandoc! pandoc_arguments, stdin_data: stdin
+      end
+
+      def pandoc_arguments
+        [
+          wrap_mode,
+          '--atx-headers',
+          '-f',
+          'textile',
+          '-t',
+          output_format
+        ]
+      end
+
+      ##
+      # Detect available output markdown format
+      # pandoc recommends format 'gfm' but that isnt available in current LTS
+      # markdown_github, which is deprecated, is however available.
+      def output_format
+        if gfm_supported?
+          'gfm'
+        else
+          'markdown_github'
+        end
+      end
+
+      ##
+      # Detect available wrap mode
+      # --wrap=preserve will keep the wrapping the same, however is only available in versions 1.16+
+      # In older versions we try to use the deprecated --no-wrap instead
+      # --atx-headers will lead to headers like `### Some header` and '## Another header'
+      def wrap_mode
+        usage = read_usage_string
+
+        # Detect wrap usage
+        if usage.include? '--wrap='
+          '--wrap=preserve'
+        elsif usage.include? '--no-wrap'
+          '--no-wrap'
+        else
+          raise 'Your pandoc version has neither --no-wrap nor --wrap=preserve. Please install a recent version of pandoc.'
+        end
+      end
+
+      ##
+      # Detect whether an output format for gfm exists
+      # so we don't have to use the legacy github_markdown format.
+      def gfm_supported?
+        read_output_formats.match? /^gfm$/
+      end
+
+      private
+
+      ##
+      # Run pandoc through open3 and raise if an exception occurred
+      def run_pandoc!(args, **options)
+        output, stderr_str, status = Open3.capture3('pandoc', *args, **options)
+        raise stderr_str unless status.success?
+
+        output
+      end
+
+      def read_usage_string
+        run_pandoc! %w[--help]
+      end
+
+      def read_output_formats
+        run_pandoc! %w[--list-output-formats]
+      end
+    end
+  end
+end

lib/open_project/text_formatting/formats/markdown/textile_converter.rb

@@ -52,7 +52,7 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 
-require 'open3'
+require_relative 'pandoc_wrapper'
 
 module OpenProject::TextFormatting::Formats
   module Markdown
@@ -186,22 +186,18 @@ module OpenProject::TextFormatting::Formats
 
         cleanup_before_pandoc(textile)
 
-        # TODO pandoc recommends format 'gfm' but that isnt available in current LTS
-        # markdown_github, which is deprecated, is however available.
-        # --wrap=preserve will keep the wrapping the same
-        # --atx-headers will lead to headers like `### Some header` and '## Another header'
-        command = %w(pandoc --wrap=preserve --atx-headers -f textile -t markdown_github)
-        markdown, stderr_str, status = begin
-          Open3.capture3(*command, stdin_data: textile)
-        rescue StandardError
-          raise "Pandoc failed with unspecific error"
-        end
-
-        raise "Pandoc failed: #{stderr_str}" unless status.success?
+        markdown = execute_pandoc_with_stdin! textile
 
         cleanup_after_pandoc(markdown)
       end
 
+      def execute_pandoc_with_stdin!(textile)
+        wrapper = PandocWrapper.new
+        wrapper.execute! textile
+      rescue StandardError => e
+        raise "Execution of pandoc failed: #{e}"
+      end
+
       def models_to_convert
         {
           ::Announcement => [:text],

spec/lib/open_project/text_formatting/markdown/pandoc_wrapper_spec.rb

@@ -0,0 +1,99 @@
+#-- encoding: UTF-8
+#-- copyright
+# OpenProject is a project management system.
+# Copyright (C) 2012-2018 the OpenProject Foundation (OPF)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe OpenProject::TextFormatting::Formats::Markdown::PandocWrapper do
+  let(:subject) { described_class.new }
+  let(:output_formats) { "gfm\n foo\n" }
+
+  before do
+    allow(subject).to receive(:read_usage_string).and_return(usage_string)
+    allow(subject).to receive(:read_output_formats).and_return(output_formats)
+  end
+
+  describe 'gfm mode' do
+    let(:usage_string) { 'does not matter' }
+    context 'when gfm exists' do
+      it 'uses gfm format' do
+        expect(subject.output_format).to eq 'gfm'
+      end
+    end
+
+    context 'when gfm does not exist' do
+      let(:output_formats) { "bar\n foo\n" }
+
+      it 'uses the legacy format' do
+        expect(subject.output_format).to eq 'markdown_github'
+      end
+    end
+  end
+
+  describe 'wrap mode' do
+    context 'when wrap=preserve exists' do
+      let(:usage_string) do
+        <<~EOS
+                        --list-output-formats                           
+                        --list-highlight-languages                      
+                        --list-highlight-styles                         
+                        --wrap=auto|none|preserve
+  -v                    --version                                       
+  -h                    --help
+        EOS
+      end
+
+      it do
+        expect(subject.wrap_mode).to eq('--wrap=preserve')
+      end
+    end
+
+    context 'when only no-wrap exists' do
+      let(:usage_string) do
+        <<~EOS
+                        --list-output-formats                           
+                        --list-highlight-languages                      
+                        --list-highlight-styles                         
+                        --no-wrap
+  -v                    --version                                       
+  -h                    --help
+        EOS
+      end
+      it do
+        expect(subject.wrap_mode).to eq('--no-wrap')
+      end
+    end
+
+    context 'when neither exists' do
+      let(:usage_string) { 'wat?' }
+      it do
+        expect { subject.wrap_mode }.to raise_error 'Your pandoc version has neither --no-wrap nor --wrap=preserve. Please install a recent version of pandoc.'
+      end
+    end
+  end
+end