Improve error message in Api::V0:ArticlesController#create (#4417)

app/controllers/api/v0/articles_controller.rb

@@ -39,7 +39,12 @@ module Api
 
       def create
         @article = Articles::Creator.call(@user, article_params)
-        render "show", status: :created, location: @article.url
+        if @article.persisted?
+          render "show", status: :created, location: @article.url
+        else
+          message = @article.errors.full_messages
+          render json: { errors: message, status: 422 }, status: :unprocessable_entity
+        end
       end
 
       def update

spec/requests/api/v0/articles_spec.rb

@@ -257,6 +257,12 @@ RSpec.describe "Api::V0::Articles", type: :request do
         expect(response).to have_http_status(:unprocessable_entity)
       end
 
+      it "fails if missing required params" do
+        tags = %w[meta discussion]
+        post_article(body_markdown: "Yo ho ho", tags: tags)
+        expect(response).to have_http_status(:unprocessable_entity)
+      end
+
       it "creates an article belonging to the user" do
         post_article(title: Faker::Book.title)
         expect(response).to have_http_status(:created)