Add convert_na_to_nil option

Closes #21

LGTM given by: @ivdma
Squashed commit of the following:

commit 2589c43
Author: timraasveld <ttimitri@gmail.com>
Date:   Wed Feb 3 09:05:57 2016 +0100

    Remove extra space

commit 6e7cb0e
Author: timraasveld <ttimitri@gmail.com>
Date:   Fri Jan 29 13:44:49 2016 +0100

    Process feedback

commit 31a9550
Author: timraasveld <ttimitri@gmail.com>
Date:   Wed Jan 27 09:00:08 2016 +0100

    Remove extra vcr recording

commit 48ece1e
Author: timraasveld <ttimitri@gmail.com>
Date:   Wed Jan 27 08:56:12 2016 +0100

    Update bundler for travis

commit 512876e
Author: timraasveld <ttimitri@gmail.com>
Date:   Tue Jan 26 17:21:26 2016 +0100

    Add changelog

commit 062a2ca
Author: timraasveld <ttimitri@gmail.com>
Date:   Tue Jan 26 17:21:09 2016 +0100

    Add convert na to nil option

.travis.yml

@@ -4,3 +4,5 @@ rvm:
   - 2.0.0-p576
   - 2.1.3
 script: bundle exec rspec spec
+before_install:
+  - gem install bundler

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.9.1
+
+* Added `convert_na_to_nil=true/false` option to Client#execute
+
 # 0.9.0
 
 * Added support for Github R repos through OpenCPU

lib/opencpu/client.rb

@@ -8,12 +8,29 @@ def initialize
     end
 
     def execute(package, function, options = {})
-      user   = options.fetch :user, :system
-      data   = options.fetch :data, {}
-      format = options.fetch :format, :json
-      github_remote = options.fetch :github_remote, false
+      user                      = options.fetch :user, :system
+      data                      = options.fetch :data, {}
+      format                    = options.fetch :format, :json
+      github_remote             = options.fetch :github_remote, false
+      should_convert_na_to_nil  = options.fetch :convert_na_to_nil, false
+
       process_query package_url(package, function, user, github_remote, :json), data, format do |response|
-        JSON.parse(response.body)
+        output = JSON.parse(response.body)
+        output = convert_na_to_nil(output) if should_convert_na_to_nil
+        output
+      end
+    end
+
+    def convert_na_to_nil(data)
+      case data
+      when 'NA'
+        nil
+      when Hash
+        data.each { |k, v| data[k] = convert_na_to_nil(v) }
+      when Array
+        data.map! { |v| convert_na_to_nil(v) }
+      else
+        data
       end
     end
 

spec/fixtures/vcr_cassettes/animation_flip_coin.yml

@@ -3004,4 +3004,3 @@ http_interactions:
         \    \n"
     http_version: 
   recorded_at: Tue, 14 Oct 2014 18:51:02 GMT
-recorded_with: VCR 2.9.3

spec/lib/opencpu/client_spec.rb

@@ -105,6 +105,15 @@
       end
     end
 
+    context 'na_to_nil = true option is given' do
+      it 'converts "na" values to nil' do
+        VCR.use_cassette :response_with_na_values do |cassette|
+          response = client.execute(:base, :identity, format: nil, data: {}, convert_na_to_nil: true)
+          expect(response).to eq [{"x"=>nil, "y"=>"not_na"}]
+        end
+      end
+    end
+
     context 'multipart form / file uploads' do
       it "works" do
         skip # vcr is broken for file uploads https://github.com/vcr/vcr/issues/441
@@ -190,6 +199,25 @@
     end
   end
 
+  describe "#convert_na_to_nil" do
+    let(:client) { described_class.new }
+
+    it "converts 'NA' values in hashes in arrays" do
+      res = client.convert_na_to_nil([4, {foo: 'NA'}])
+      expect(res[1][:foo]).to be_nil
+    end
+
+    it "converts 'NA' values in arrays in hashes" do
+      res = client.convert_na_to_nil(foo: [1, 'NA'])
+      expect(res[:foo][1]).to be_nil
+    end
+
+    it 'leaves other values alone' do
+      res = client.convert_na_to_nil(foo: [1, 'NOTNA'])
+      expect(res[:foo][1]).to eq 'NOTNA'
+    end
+  end
+
   describe '#request_options' do
     it 'uses verify_ssl setting' do
       expect(described_class.new.send(:request_options, {}, nil)[:verify]).to be_truthy