Add markdown to article api response (#3394)

* Add failing test asserting markdown is returned

* Add markdown to the get article api response

app/views/api/v0/articles/show.json.jbuilder

@@ -21,6 +21,7 @@ json.published_at       @article.published_at&.utc&.iso8601
 json.last_comment_at    @article.last_comment_at&.utc&.iso8601
 
 json.body_html @article.processed_html
+json.body_markdown @article.body_markdown
 json.ltag_style(@article.liquid_tags_used.map { |ltag| Rails.application.assets["ltags/#{ltag}.css"].to_s.html_safe })
 json.ltag_script(@article.liquid_tags_used.map { |ltag| ltag.script.html_safe })
 

spec/requests/api/v0/articles_spec.rb

@@ -83,6 +83,11 @@ RSpec.describe "Api::V0::Articles", type: :request do
       get "/api/articles/#{article.id}"
       expect(json_response["title"]).to eq(article.title)
     end
+    
+    it "contains article markdown content" do
+      get "/api/articles/#{article.id}"
+      expect(json_response["body_markdown"]).to eq(article.body_markdown)
+    end
 
     it "fails with an unpublished article" do
       article.update_columns(published: false)