updated index

app/controllers/api/v1/todos_controller.rb

@@ -0,0 +1,45 @@
+class Api::V1::TodosController < ApplicationController
+
+  def index
+    @todo = Todo.all
+
+    render json: @todo
+  end
+
+  def show
+    @todo = Todo.find(params[:id])
+  end
+
+  def create
+    @todo = Todo.new(todo_params)
+
+    if @todo.save
+      render json: @todo, status: :created
+    else
+      render @todo.errors, status: :unprocessable_entity
+    end
+  end
+
+  def update
+    @todo = Todo.find(params[:id])
+
+    if @todo.update(todo_params)
+      head :no_content
+    else
+      render @todo.errors, status: :unprocessable_entity
+    end
+  end
+
+  def destroy
+    @todo = Todo.find(params[:id])
+    @todo.destroy
+
+    head :no_content
+  end
+
+  private
+
+  def todo_params
+    params.permit(:title, :order, :completed)
+  end
+end

app/serializers/todo_serializer.rb

@@ -0,0 +1,3 @@
+class TodoSerializer < ActiveModel::Serializer
+  attributes :id, :title, :order, :completed
+end

app/views/todos/index.json.jbuilder

@@ -0,0 +1 @@
+json.(@todo, :id, :title, :order, :completed)

test/controllers/api/v1/todos_controller_test.rb

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class Api::V1::TodosControllerTest < ActionController::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end