Adds def update to activity controller, and unit tests

app/controllers/api/v1/activities_controller.rb

@@ -1,6 +1,7 @@
 class Api::V1::ActivitiesController < ApplicationController
   before_action :set_activity, only: %i[show update destroy]
   before_action :check_login
+  before_action :check_owner, only: %i[update]
 
   def index
     render json: Activity.all
@@ -19,6 +20,14 @@ class Api::V1::ActivitiesController < ApplicationController
     end
   end
 
+  def update
+    if @activity.update(activity_params)
+      render json: @product
+    else
+      render json: @product.erros, status: :unprocessable_entity
+    end
+  end
+
   private
 
   # Only allow a trusted parameter "white list" through.
@@ -29,4 +38,8 @@ class Api::V1::ActivitiesController < ApplicationController
   def set_activity
     @activity = Activity.find(params[:id])
   end
+
+  def check_owner
+    head :forbidden unless @activity.author_id == current_user&.id
+  end
 end