fix: Make category non-mandatory (#7117)

Creating articles in a new help center without categories throws an error. This PR fixes that.

app/views/api/v1/accounts/articles/_article.json.jbuilder

@@ -8,11 +8,12 @@ json.position article.position
 json.account_id article.account_id
 json.updated_at article.updated_at.to_i
 json.meta article.meta
+
 json.category do
   json.id article.category_id
-  json.name article.category.name
-  json.slug article.category.slug
-  json.locale article.category.locale
+  json.name article.category&.name
+  json.slug article.category&.slug
+  json.locale article.category&.locale
 end
 
 json.views article.views

spec/controllers/api/v1/accounts/articles_controller_spec.rb

@@ -41,6 +41,29 @@ RSpec.describe 'Api::V1::Accounts::Articles', type: :request do
         expect(json_response['payload']['position']).to be(3)
       end
 
+      it 'creates article even if category is not provided' do
+        article_params = {
+          article: {
+            category_id: nil,
+            description: 'test description',
+            title: 'MyTitle',
+            slug: 'my-title',
+            content: 'This is my content.',
+            status: :published,
+            author_id: agent.id,
+            position: 3
+          }
+        }
+        post "/api/v1/accounts/#{account.id}/portals/#{portal.slug}/articles",
+             params: article_params,
+             headers: agent.create_new_auth_token
+        expect(response).to have_http_status(:success)
+        json_response = JSON.parse(response.body)
+        expect(json_response['payload']['title']).to eql('MyTitle')
+        expect(json_response['payload']['status']).to eql('draft')
+        expect(json_response['payload']['position']).to be(3)
+      end
+
       it 'associate to the root article' do
         root_article = create(:article, category: category, slug: 'root-article', portal: portal, account_id: account.id, author_id: agent.id,
                                         associated_article_id: nil)