Validate that API article params are a Hash (#5963)

* Add check for article param being a Hash & spec

* Remove unnecessary blank line

* Move logic to private method and before_action call

* Change check_if to validate

* Use is_a? to type check

* Fix type check for specs

app/controllers/api/v0/articles_controller.rb

@@ -7,6 +7,8 @@ module Api
       before_action :authenticate!, only: :me
       before_action -> { doorkeeper_authorize! :public }, only: %w[index show], if: -> { doorkeeper_token }
 
+      before_action :validate_article_param_is_hash, only: %w[create update]
+
       before_action :set_cache_control_headers, only: %i[index show]
 
       before_action :cors_preflight_check
@@ -116,6 +118,13 @@ module Api
             @user.any_admin?
         end
       end
+
+      def validate_article_param_is_hash
+        return if params.to_unsafe_h.dig(:article).is_a?(Hash)
+
+        message = "article param must be a JSON object. You provided article as a #{params[:article].class.name}"
+        render json: { error: message, status: 422 }, status: :unprocessable_entity
+      end
     end
   end
 end

spec/requests/api/v0/articles_spec.rb

@@ -474,6 +474,16 @@ RSpec.describe "Api::V0::Articles", type: :request do
         expect(response).to have_http_status(:unprocessable_entity)
       end
 
+      it "fails if params are not a Hash" do
+        # Not using the nifty post_article helper method because it expects a Hash
+        headers = { "api-key" => api_secret.secret, "content-type" => "application/json" }
+        string_params = "this_string_is_definitely_not_a_hash"
+        post api_articles_path, params: { article: string_params }.to_json, headers: headers
+
+        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response.parsed_body["error"]).to be_present
+      end
+
       it "creates an article belonging to the user" do
         post_article(title: Faker::Book.title)
         expect(response).to have_http_status(:created)
@@ -941,6 +951,16 @@ RSpec.describe "Api::V0::Articles", type: :request do
         expect(response).to have_http_status(:ok)
         expect(article.reload.organization).to eq(organization)
       end
+
+      it "fails if params are not a Hash" do
+        # Not using the nifty put_article helper method because it expects a Hash
+        headers = { "api-key" => api_secret.secret, "content-type" => "application/json" }
+        string_params = "this_string_is_definitely_not_a_hash"
+        put path, params: { article: string_params }.to_json, headers: headers
+
+        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response.parsed_body["error"]).to be_present
+      end
     end
   end
 end