Address reviewer comments

- Add shared examples
- Add credit to community contributor

changelogs/unreleased/37359-cablett-support-envelope-to.yml

 ---
 title: Accept `Envelope-To` as possible location for Service Desk key
 merge_request: 22354
-author:
+author: Max Winterstein
 type: added

spec/fixtures/emails/envelope_to_header.eml

-Return-Path: <jake@adventuretime.ooo>
-Received: from iceking.adventuretime.ooo ([unix socket]) by iceking (Cyrus v2.2.13-Debian-2.2.13-19+squeeze3) with LMTPA; Thu, 13 Jun 2013 17:03:50 -0400
-Received: from mail-ie0-x234.google.com (mail-ie0-x234.google.com [IPv6:2607:f8b0:4001:c03::234]) by iceking.adventuretime.ooo (8.14.3/8.14.3/Debian-9.4) with ESMTP id r5DL3nFJ016967 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for <incoming+gitlabhq/gitlabhq@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 17:03:50 -0400
-Received: by mail-ie0-f180.google.com with SMTP id f4so21977375iea.25 for <incoming+gitlabhq/gitlabhq@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 14:03:48 -0700
+Return-Path: <jake@example.com>
+Received: from myserver.example.com ([unix socket]) by myserver (Cyrus v2.2.13-Debian-2.2.13-19+squeeze3) with LMTPA; Thu, 13 Jun 2013 17:03:50 -0400
+Received: from mail.example.com (mail.example.com [IPv6:2607:f8b0:4001:c03::234]) by myserver.example.com (8.14.3/8.14.3/Debian-9.4) with ESMTP id r5DL3nFJ016967 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for <incoming+gitlabhq/gitlabhq@example.com>; Thu, 13 Jun 2013 17:03:50 -0400
+Received: by myserver.example.com with SMTP id f4so21977375iea.25 for <incoming+gitlabhq/gitlabhq@appmail.example.com>; Thu, 13 Jun 2013 14:03:48 -0700
 Received: by 10.0.0.1 with HTTP; Thu, 13 Jun 2013 14:03:48 -0700
-From: "jake@adventuretime.ooo" <jake@adventuretime.ooo>
-To: "support@adventuretime.ooo" <support@adventuretime.ooo>
-Subject: Insert witty Adventure Time reference
+From: "jake@example.com" <jake@example.com>
+To: "support@example.com" <support@example.com>
+Subject: Insert hilarious subject line here
 Date: Tue, 26 Nov 2019 14:22:41 +0000
 Message-ID: <7e2296f83dbf4de388cbf5f56f52c11f@EXDAG29-1.EXCHANGE.INT>
 Accept-Language: de-DE, en-US
@@ -17,7 +17,7 @@ x-originating-ip: [62.96.54.178]
 Content-Type: multipart/alternative;
 	boundary="_000_7e2296f83dbf4de388cbf5f56f52c11fEXDAG291EXCHANGEINT_"
 MIME-Version: 1.0
-Envelope-To: incoming+gitlabhq/gitlabhq+auth_token@appmail.adventuretime.ooo
+Envelope-To: incoming+gitlabhq/gitlabhq+auth_token@appmail.example.com
 
 --_000_7e2296f83dbf4de388cbf5f56f52c11fEXDAG291EXCHANGEINT_
 Content-Type: text/plain; charset="iso-8859-1"

spec/fixtures/emails/forwarded_new_issue.eml

-Delivered-To: incoming+gitlabhq/gitlabhq+auth_token@appmail.adventuretime.ooo
-Return-Path: <jake@adventuretime.ooo>
-Received: from iceking.adventuretime.ooo ([unix socket]) by iceking (Cyrus v2.2.13-Debian-2.2.13-19+squeeze3) with LMTPA; Thu, 13 Jun 2013 17:03:50 -0400
-Received: from mail-ie0-x234.google.com (mail-ie0-x234.google.com [IPv6:2607:f8b0:4001:c03::234]) by iceking.adventuretime.ooo (8.14.3/8.14.3/Debian-9.4) with ESMTP id r5DL3nFJ016967 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for <incoming+gitlabhq/gitlabhq@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 17:03:50 -0400
-Received: by mail-ie0-f180.google.com with SMTP id f4so21977375iea.25 for <incoming+gitlabhq/gitlabhq@appmail.adventuretime.ooo>; Thu, 13 Jun 2013 14:03:48 -0700
+Delivered-To: incoming+gitlabhq/gitlabhq+auth_token@appmail.example.com
+Return-Path: <jake@example.com>
+Received: from iceking.example.com ([unix socket]) by iceking (Cyrus v2.2.13-Debian-2.2.13-19+squeeze3) with LMTPA; Thu, 13 Jun 2013 17:03:50 -0400
+Received: from mail-ie0-x234.google.com (mail-ie0-x234.google.com [IPv6:2607:f8b0:4001:c03::234]) by iceking.example.com (8.14.3/8.14.3/Debian-9.4) with ESMTP id r5DL3nFJ016967 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for <incoming+gitlabhq/gitlabhq@appmail.example.com>; Thu, 13 Jun 2013 17:03:50 -0400
+Received: by mail-ie0-f180.google.com with SMTP id f4so21977375iea.25 for <incoming+gitlabhq/gitlabhq@appmail.example.com>; Thu, 13 Jun 2013 14:03:48 -0700
 Received: by 10.0.0.1 with HTTP; Thu, 13 Jun 2013 14:03:48 -0700
 Date: Thu, 13 Jun 2013 17:03:48 -0400
-From: Jake the Dog <jake@adventuretime.ooo>
-Delivered-To: support@adventuretime.ooo
-To: support@adventuretime.ooo
+From: Jake the Dog <jake@example.com>
+Delivered-To: support@example.com
+To: support@example.com
 Message-ID: <CADkmRc+rNGAGGbV2iE5p918UVy4UyJqVcXRO2=otppgzduJSg@mail.gmail.com>
 Subject: New Issue by email
 Mime-Version: 1.0

spec/lib/gitlab/email/receiver_spec.rb

@@ -5,7 +5,7 @@ require 'spec_helper'
 describe Gitlab::Email::Receiver do
   include_context :email_shared_context
 
-  context "when the email contains a valid email address in a header" do
+  context 'when the email contains a valid email address in a header' do
     let(:handler) { double(:handler) }
 
     before do
@@ -13,24 +13,19 @@ describe Gitlab::Email::Receiver do
       allow(handler).to receive(:metrics_params)
       allow(handler).to receive(:metrics_event)
 
-      expect(Gitlab::Email::Handler).to receive(:for).with(an_instance_of(Mail::Message), 'gitlabhq/gitlabhq+auth_token').and_return(handler)
-      stub_incoming_email_setting(enabled: true, address: "incoming+%{key}@appmail.adventuretime.ooo")
+      stub_incoming_email_setting(enabled: true, address: "incoming+%{key}@appmail.example.com")
     end
 
     context 'when in a Delivered-To header' do
       let(:email_raw) { fixture_file('emails/forwarded_new_issue.eml') }
 
-      it "finds the mail key" do
-        receiver.execute
-      end
+      it_behaves_like 'correctly finds the mail key'
     end
 
     context 'when in an Envelope-To header' do
       let(:email_raw) { fixture_file('emails/envelope_to_header.eml') }
 
-      it "finds the mail key" do
-        receiver.execute
-      end
+      it_behaves_like 'correctly finds the mail key'
     end
   end
 

spec/support/shared_examples/email_shared_examples.rb

+# frozen_string_literal: true
+
+shared_examples_for 'correctly finds the mail key' do
+  specify do
+    expect(Gitlab::Email::Handler).to receive(:for).with(an_instance_of(Mail::Message), 'gitlabhq/gitlabhq+auth_token').and_return(handler)
+
+    receiver.execute
+  end
+end