Add create feature to variables API

lib/api/variables.rb

@@ -41,6 +41,24 @@ module API
         present variables.first, with: Entities::Variable
       end
+      # Create a new variable in project
+      #
+      # Parameters:
+      #   id (required) - The ID of a project
+      #   key (required) - The key of variable being created
+      #   value (required) - The value of variable being created
+      # Example Request:
+      #   POST /projects/:id/variables
+      post ':id/variables' do
+        required_attributes! [:key, :value]
+
+        variable = user_project.variables.create(key: params[:key], value: params[:value])
+        return render_validation_error!(variable) unless variable.valid?
+        variable.save!
+
+        present variable, with: Entities::Variable
+      end
+
       # Update existing variable of a project
       #
       # Parameters:
@@ -75,6 +93,8 @@ module API
         return not_found!('Variable') unless variable
         variable.destroy
+
+        present variable, with: Entities::Variable
       end
     end
   end

spec/factories/ci/variables.rb

@@ -16,7 +16,7 @@
 FactoryGirl.define do
   factory :ci_variable, class: Ci::Variable do
-    id 1
+    id 10
     key 'TEST_VARIABLE_1'
     value 'VALUE_1'

spec/requests/api/variables_spec.rb

@@ -79,6 +79,44 @@ describe API::API, api: true do
     end
   end
+  describe 'POST /projects/:id/variables' do
+    context 'authorized user with proper permissions' do
+      it 'should create variable' do
+        expect do
+          post api("/projects/#{project.id}/variables", user), key: 'TEST_VARIABLE_2', value: 'VALUE_2'
+        end.to change{project.variables.count}.by(1)
+
+        expect(response.status).to eq(201)
+        expect(json_response['key']).to eq('TEST_VARIABLE_2')
+        expect(json_response['value']).to eq('VALUE_2')
+      end
+
+      it 'should not allow to duplicate variable key' do
+        expect do
+          post api("/projects/#{project.id}/variables", user), key: 'TEST_VARIABLE_1', value: 'VALUE_2'
+        end.to change{project.variables.count}.by(0)
+
+        expect(response.status).to eq(400)
+      end
+    end
+
+    context 'authorized user with invalid permissions' do
+      it 'should not create variable' do
+        post api("/projects/#{project.id}/variables", user2)
+
+        expect(response.status).to eq(403)
+      end
+    end
+
+    context 'unauthorized user' do
+      it 'should not create variable' do
+        post api("/projects/#{project.id}/variables")
+
+        expect(response.status).to eq(401)
+      end
+    end
+  end
+
   describe 'PUT /projects/:id/variables/:variable_id' do
     context 'authorized user with proper permissions' do
       it 'should update variable data' do