add job run mailer and start hooking up mailer to jobrun model

app/mailers/application_mailer.rb

@@ -1,4 +1,4 @@
 class ApplicationMailer < ActionMailer::Base
-  default from: 'from@example.com'
+  default from: 'no-reply-preassembly@.stanford.edu'
   layout 'mailer'
 end

app/mailers/job_mailer.rb

@@ -0,0 +1,10 @@
+class JobMailer < ApplicationMailer
+  default from: 'no-reply-preassembly-job@stanford.edu'
+
+  def completion_email
+    @job = params[:job_run]
+    @user = @job.bundle_context.user
+    mail(to: @user.email, subject: 'Your pre-assembly job has completed')
+  end
+
+end

app/models/job_run.rb

@@ -2,6 +2,7 @@ class JobRun < ApplicationRecord
   belongs_to :bundle_context
   validates :job_type, presence: true
   after_create :enqueue!
+  after_update :send_notification, if: -> { saved_change_to_output_location? }
 
   enum job_type: {
     "discovery_report" => 0,
@@ -14,4 +15,10 @@ def enqueue!
     return nil unless persisted?
     "#{job_type.camelize}Job".constantize.perform_later(self)
   end
+
+  def send_notification
+    return unless output_location
+    JobMailer.with(job_run: self).completion_email.deliver_later
+  end
+
 end

app/models/user.rb

@@ -2,4 +2,9 @@ class User < ApplicationRecord
   devise :remote_user_authenticatable # We don't want other (default) Devise modules
   has_many :bundle_contexts
   validates :sunet_id, presence: true, uniqueness: true, null: false
+
+  def email
+    "#{sunet_id}@stanford.edu"
+  end
+
 end

app/views/job_mailer/completion_email.text.erb

@@ -0,0 +1 @@
+<%=@user.sunet_id%>, your <%=@job.job_type%> job #<%=@job.id%> completed.  View the job details here: "=url_for(@job) will go here".

spec/mailers/job_mailer_spec.rb

@@ -0,0 +1,37 @@
+require "rails_helper"
+
+RSpec.describe JobMailer, type: :mailer do
+  let(:user) do
+    User.new(sunet_id: "Jdoe")
+  end
+
+  let(:bc) do
+    BundleContext.new(id: 1,
+                      project_name: "SmokeTest",
+                      content_structure: 1,
+                      bundle_dir: "spec/test_data/images_jp2_tif",
+                      staging_style_symlink: false,
+                      content_metadata_creation: 1,
+                      user: user)
+  end
+
+  let(:discovery_report_run) do
+    JobRun.new(id: 1,
+               output_location: "/path/to/report",
+               bundle_context: bc,
+               job_type: "discovery_report")
+  end
+
+  let(:job_notification) { JobMailer.with(job_run: discovery_report_run).completion_email }
+
+  it 'renders the headers' do
+    expect(job_notification.subject).to eq("Your pre-assembly job has completed")
+    expect(job_notification.to).to eq(["Jdoe@stanford.edu"])
+    expect(job_notification.from).to eq(["no-reply-preassembly-job@stanford.edu"])
+  end
+
+  it 'renders the body' do
+    expect(job_notification.body.encoded).to include("Jdoe, your discovery_report job #1 completed")
+  end
+
+end

spec/models/job_run_spec.rb

@@ -1,7 +1,8 @@
 RSpec.describe JobRun, type: :model do
   let(:user) { User.new(sunet_id: 'Jdoe') }
   let(:bc) do
-    BundleContext.new(project_name: 'SmokeTest',
+    BundleContext.new(id: 1,
+                      project_name: 'SmokeTest',
                       content_structure: 1,
                       bundle_dir: 'spec/test_data/bundle_input_g',
                       staging_style_symlink: false,
@@ -30,6 +31,30 @@
     end
   end
 
+  describe 'send_notification' do
+    let(:mock_mailer) { double JobMailer }
+    let(:mock_delivery) { double ActionMailer::MessageDelivery }
+    before { job_run.save }
+    it 'does nothing if output_location not saved' do
+      expect(job_run).not_to receive(:send_notification)
+      job_run.save
+    end
+    it 'does not actually send the email if output_location is nil' do
+      expect(job_run).to receive(:send_notification).and_call_original
+      expect(JobMailer).not_to receive(:with)
+      job_run.output_location = nil
+      job_run.save
+    end
+    it 'sends a notification if output_location is updated a new non-nil value' do
+      expect(job_run).to receive(:send_notification).and_call_original
+      expect(JobMailer).to receive(:with).with(job_run: job_run).and_return(mock_mailer)
+      expect(mock_mailer).to receive(:completion_email).and_return(mock_delivery)
+      expect(mock_delivery).to receive(:deliver_later)
+      job_run.output_location += '/tmp'
+      job_run.save
+    end
+  end
+
   describe '#job_type enum' do
     it 'defines expected values' do
       is_expected.to define_enum_for(:job_type).with(

spec/models/user_spec.rb

@@ -11,7 +11,6 @@
     it { is_expected.to validate_uniqueness_of(:sunet_id) }
     it { is_expected.to validate_presence_of(:sunet_id) }
     it { is_expected.to have_many(:bundle_contexts) }
-
     describe 'enforces unique constraint on sunet_id' do
       let(:required_attributes) do
         { sunet_id: "tempdoe" }
@@ -28,4 +27,12 @@
       end
     end
   end
+
+  context "email address" do
+    subject(:user) { User.new(sunet_id: "jdoe") }
+
+    it "returns the user's email address based on sunet" do
+      expect(user.email).to eq('jdoe@stanford.edu')
+    end
+  end
 end