Add frontend view and API controllers for PayPal checkout

Adds routes for orders_controller - which allows the creation of
orders on PayPals side. This is called when the paypal button is
first clicked, to send the order info to PayPal so they know how
to build the order and how much is going to be charged.
Also adds a route for payments_controller, which handles the creation
of the source/payment for the order.
en.yml was updated to display nothing for validation errors for
paypal_order_id - the reason is that when you try to proceed
without having created a payment on PayPal, the error message
"Payments Source #{en.yml entry} Can't Be Blank" appears, with
whatever you've set in the paypal_order_id entry appearing in the
middle of the string. We may want to adjust the entire error message,
but I think it's clearer with nothing in the middle - so just
"Payments Source Can't Be Blank", instead of "Payments Source
Paypal Order Id Can't Be Blank".
Also adds tests for the frontend! 🎉

app/assets/javascripts/spree/frontend/solidus_paypal_commerce_platform.js

@@ -1,2 +1,2 @@
-// Placeholder manifest file.
-// the installer will append this file to the app vendored assets here: vendor/assets/javascripts/spree/frontend/all.js'
+//= require spree/frontend/solidus_paypal_commerce_platform/namespace
+//= require spree/frontend/solidus_paypal_commerce_platform/buttons

app/assets/javascripts/spree/frontend/solidus_paypal_commerce_platform/buttons.js

@@ -0,0 +1,21 @@
+SolidusPaypalCommercePlatform.renderButton = function(payment_method_id) {
+  paypal.Buttons({
+    createOrder: function (data, actions) {
+      return Spree.ajax({
+        url: '/solidus_paypal_commerce_platform/orders',
+        method: 'POST',
+        data: {
+          payment_method_id: payment_method_id,
+          order_id: Spree.current_order_id,
+          order_token: Spree.current_order_token
+        }
+      }).then(function(res) {
+        return res.table.id;
+      })
+    },
+    onApprove: function (data, actions) {
+      $("#payments_source_paypal_order_id").val(data.orderID)
+      $("#checkout_form_payment").submit()
+    }
+  }).render('#paypal-button-container')
+}

app/assets/javascripts/spree/frontend/solidus_paypal_commerce_platform/namespace.js

@@ -0,0 +1 @@
+window.SolidusPaypalCommercePlatform = {}

app/controllers/solidus_paypal_commerce_platform/orders_controller.rb

@@ -0,0 +1,26 @@
+module SolidusPaypalCommercePlatform
+  class OrdersController < ::Spree::Api::BaseController
+    before_action :load_order
+    before_action :load_payment_method
+    skip_before_action :authenticate_user
+
+    def create
+      authorize! :update, @order, order_token
+      request = SolidusPaypalCommercePlatform::Requests.new(
+        @payment_method.client_id, @payment_method.client_secret
+      ).create_order(@order, @payment_method.auto_capture)
+      render json: request, status: :ok
+    end
+
+    private
+
+    def load_order
+      @order = Spree::Order.find_by!(number: params[:order_id])
+    end
+
+    def load_payment_method
+      @payment_method = Spree::PaymentMethod.find(params[:payment_method_id])
+    end
+
+  end
+end

app/controllers/solidus_paypal_commerce_platform/payments_controller.rb

@@ -0,0 +1,43 @@
+module SolidusPaypalCommercePlatform
+  class PaymentsController < ::Spree::Api::BaseController
+    before_action :load_order
+    skip_before_action :authenticate_user
+
+    def create
+      authorize! :update, @order, order_token
+      paypal_order_id = paypal_params[:paypal_order_id]
+
+      if !paypal_order_id
+        return redirect_to checkout_state_path(@order.state), notice: "Invalid order confirmation data passed in"
+      end
+
+      if @order.complete?
+        return redirect_to spree.order_path(@order), notice: "Order is already in complete state"
+      end
+
+      source = SolidusPaypalCommercePlatform::Source.new(paypal_order_id: paypal_order_id)
+
+      source.transaction do
+        if source.save!
+          payment = @order.payments.create!({
+            payment_method_id: paypal_params[:payment_method_id],
+            source: source
+          })
+
+          render json: {}, status: :ok
+        end
+      end
+    end
+
+    private
+
+    def paypal_params
+      params.permit(:paypal_order_id, :order_id, :order_token, :payment_method_id)
+    end
+
+    def load_order
+      @order = Spree::Order.find_by!(number: params[:order_id])
+    end
+
+  end
+end

config/locales/en.yml

@@ -1,5 +1,8 @@
 en:
   activerecord:
+    attributes:
+      solidus_paypal_commerce_platform/source:
+        paypal_order_id: ""
     models:
       solidus_paypal_commerce_platform/gateway: Paypal Commerce Platform
   hello: Hello world

config/routes.rb

@@ -3,5 +3,6 @@
 SolidusPaypalCommercePlatform::Engine.routes.draw do
   # Add your extension routes here
   resources :wizard, only: [:create]
-  # post :paypal_wizard, to: "wizard#create"
+  resources :orders, only: [:create]
+  resources :payments, only: [:create]
 end

lib/views/frontend/spree/checkout/payment/_paypal_commerce_platform.html.erb

@@ -0,0 +1,12 @@
+<script
+  src="<%= payment_method.sdk_url %>">
+</script>
+
+<div id="paypal-button-container"></div>
+<input type="hidden" name="payment_source[<%= payment_method.id %>][paypal_order_id]" id="payments_source_paypal_order_id">
+
+<script>
+  $( document ).ready(function() {
+    SolidusPaypalCommercePlatform.renderButton("<%= payment_method.id %>")
+  })
+</script>

spec/factories/paypal_payment_method_factory.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :paypal_payment_method, class: 'SolidusPaypalCommercePlatform::Gateway' do
+    type { "SolidusPaypalCommercePlatform::Gateway" }
+    name { "PayPal Payment Method" }
+    preferences { 
+      { 
+        client_id: SecureRandom.hex(8),
+        client_secret: SecureRandom.hex(10) 
+      } 
+    }
+  end
+end

spec/features/frontend/checkout_spec.rb

@@ -0,0 +1,55 @@
+require 'spec_helper'
+
+RSpec.describe "Checkout" do
+
+  context "paypal payment method" do
+    let(:order) { Spree::TestingSupport::OrderWalkthrough.up_to(:payment) }
+    let(:paypal_payment_method) { create(:paypal_payment_method) }
+
+    before do
+      user = create(:user)
+      order.user = user
+      order.recalculate
+
+      paypal_payment_method
+      allow_any_instance_of(Spree::CheckoutController).to receive_messages(current_order: order, try_spree_current_user: user)
+    end
+
+    it "should generate a js file with the correct credentials and intent attached" do
+      visit '/checkout/payment'
+      expect(page).to have_css(
+        'script[src*="sdk/js?client-id=' + paypal_payment_method.preferences[:client_id] + '&intent=authorize"]', visible: false
+        )
+    end
+
+    context "when auto-capture is set to true" do
+      it "should generate a js file with intent capture" do
+        paypal_payment_method.update(auto_capture: true)
+        visit '/checkout/payment'
+        expect(page).to have_css(
+          'script[src*="sdk/js?client-id=' + paypal_payment_method.preferences[:client_id] + '&intent=capture"]', visible: false
+          )
+      end
+    end
+
+    context "if no payment has been made" do
+      it "should fail to process" do
+        visit '/checkout/payment'
+        choose(option: paypal_payment_method.id)
+        click_button("Save and Continue")
+        expect(page).to have_content("Payments source can't be blank")
+      end
+    end
+
+    context "if payment has been made" do
+      it "should proceed to the next step" do
+        visit '/checkout/payment'
+        choose(option: paypal_payment_method.id)
+        find(:xpath, "//input[@id='payments_source_paypal_order_id']", visible: false).set SecureRandom.hex(8)
+        click_button("Save and Continue")
+        expect(page).to have_css(".current", text: "Confirm")
+      end
+    end
+
+  end
+end

spec/models/gateway_spec.rb

@@ -0,0 +1,82 @@
+require 'spec_helper'
+require 'paypal-checkout-sdk'
+
+RSpec.describe "SolidusPaypalCommercePlatform::Gateway", type: :model do
+  let(:paypal_payment_method) { create(:paypal_payment_method) }
+  let(:payment) { create(:payment) }
+
+  before do
+    response = OpenStruct.new(
+      status_code: 201, 
+      result: OpenStruct.new(
+        purchase_units: [
+          OpenStruct.new(
+            payments: OpenStruct.new(
+              authorizations: [
+                OpenStruct.new(id: SecureRandom.hex(4))
+                ]
+              )
+            )
+          ]
+        )
+      ) 
+
+    allow_any_instance_of(PayPal::PayPalHttpClient).to receive(:execute) { response }
+    allow_any_instance_of(PayPal::SandboxEnvironment).to receive(:authorizationString) { "test auth" }
+  end
+
+  context "#purchase" do
+    it "should send a purchase request to paypal" do
+      paypal_order_id = SecureRandom.hex(8)
+      source = paypal_payment_method.payment_source_class.create(paypal_order_id: paypal_order_id)
+      request = {
+        path: "/v2/checkout/orders/#{paypal_order_id}/capture",
+        headers: {
+          "Content-Type" => "application/json",
+          "Authoriation" => "test auth",
+          "PayPal-Partner-Attribution-Id" => "Solidus_PCP_SP",
+        },
+        verb: "POST"
+      }
+      expect(SolidusPaypalCommercePlatform::Requests::Request).to receive(:new).with(request)
+      paypal_payment_method.purchase(1000,source,{})
+    end
+  end
+
+  context "#authorize" do
+    it "should send an authorize request to paypal" do
+      paypal_order_id = SecureRandom.hex(8)
+      source = paypal_payment_method.payment_source_class.create(paypal_order_id: paypal_order_id)
+      request = {
+        path: "/v2/checkout/orders/#{paypal_order_id}/authorize",
+        headers: {
+          "Content-Type" => "application/json",
+          "Authoriation" => "test auth",
+          "PayPal-Partner-Attribution-Id" => "Solidus_PCP_SP",
+        },
+        verb: "POST"
+      }
+      expect(SolidusPaypalCommercePlatform::Requests::Request).to receive(:new).with(request)
+      paypal_payment_method.authorize(1000,source,{})
+    end
+  end
+
+  context "#capture" do
+    it "should send a capture request to paypal" do
+      authorization_id = SecureRandom.hex(8)
+      source = paypal_payment_method.payment_source_class.create(authorization_id: authorization_id)
+      payment.source = source
+      request = {
+        path: "/v2/payments/authorizations/#{authorization_id}/capture",
+        headers: {
+          "Content-Type" => "application/json",
+          "Authoriation" => "test auth",
+          "PayPal-Partner-Attribution-Id" => "Solidus_PCP_SP",
+        },
+        verb: "POST"
+      }
+      expect(SolidusPaypalCommercePlatform::Requests::Request).to receive(:new).with(request)
+      paypal_payment_method.capture(1000,{},{originator: payment})
+    end
+  end
+end

spec/spec_helper.rb

@@ -10,6 +10,7 @@
 
 # Requires factories and other useful helpers defined in spree_core.
 require 'solidus_dev_support/rspec/feature_helper'
+require 'spree/testing_support/order_walkthrough'
 
 # Requires supporting ruby files with custom matchers and macros, etc,
 # in spec/support/ and its subdirectories.