Grapfiy the CI::Triggers API

lib/ci/api/triggers.rb

 module Ci
   module API
-    # Build Trigger API
     class Triggers < Grape::API
       resource :projects do
-        # Trigger a GitLab CI project build
-        #
-        # Parameters:
-        #   id (required) - The ID of a CI project
-        #   ref (required) - The name of project's branch or tag
-        #   token (required) - The uniq token of trigger
-        # Example Request:
-        #   POST /projects/:id/ref/:ref/trigger
+        desc 'Trigger a GitLab CI project build' do
+          success Entities::TriggerRequest
+        end
+        params do
+          requires :id, type: Integer, desc: 'The ID of a CI project'
+          requires :ref, type: String, desc: "The name of project's branch or tag"
+          requires :token, type: String, desc: 'The unique token of the trigger'
+          optional :variables, type: Hash, desc: 'Optional build variables'
+        end
         post ":id/refs/:ref/trigger" do
-          required_attributes! [:token]
-
-          project = Project.find_by(ci_id: params[:id].to_i)
-          trigger = Ci::Trigger.find_by_token(params[:token].to_s)
+          project = Project.find_by(ci_id: params[:id])
+          trigger = Ci::Trigger.find_by_token(params[:token])
           not_found! unless project && trigger
           unauthorized! unless trigger.project == project
 
-          # validate variables
-          variables = params[:variables]
-          if variables
-            unless variables.is_a?(Hash)
-              render_api_error!('variables needs to be a hash', 400)
-            end
-
+          # Validate variables
+          variables = params[:variables].to_h
           unless variables.all? { |key, value| key.is_a?(String) && value.is_a?(String) }
             render_api_error!('variables needs to be a map of key-valued strings', 400)
           end
 
-            # convert variables from Mash to Hash
-            variables = variables.to_h
-          end
-
           # create request and trigger builds
-          trigger_request = Ci::CreateTriggerRequestService.new.execute(project, trigger, params[:ref].to_s, variables)
+          trigger_request = Ci::CreateTriggerRequestService.new.execute(project, trigger, params[:ref], variables)
           if trigger_request
             present trigger_request, with: Entities::TriggerRequest
           else

spec/requests/ci/api/triggers_spec.rb

@@ -60,7 +60,8 @@ describe Ci::API::Triggers do
         it 'validates variables to be a hash' do
           post ci_api("/projects/#{project.ci_id}/refs/master/trigger"), options.merge(variables: 'value')
           expect(response).to have_http_status(400)
-          expect(json_response['message']).to eq('variables needs to be a hash')
+
+          expect(json_response['error']).to eq('variables is invalid')
         end
 
         it 'validates variables needs to be a map of key-valued strings' do