Consolidate some application email receiver code in preparation for API changes

Summary:
Ref T7477. The various "create a new X via email" applications (Paste, Differential, Maniphest, etc) all have a bunch of duplicate code.

The inheritance stack here is generally a little weird. Extend these from a shared parent to reduce the number of callsites I need to change when this API is adjusted for T7477.

Test Plan: Ran unit tests. This will get more thorough testing once more pieces are in place.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T7477

Differential Revision: https://secure.phabricator.com/D19950

src/__phutil_library_map__.php

@@ -2111,6 +2111,7 @@ phutil_register_library_map(array(
     'PhabricatorApplicationEditHTTPParameterHelpView' => 'applications/transactions/view/PhabricatorApplicationEditHTTPParameterHelpView.php',
     'PhabricatorApplicationEditor' => 'applications/meta/editor/PhabricatorApplicationEditor.php',
     'PhabricatorApplicationEmailCommandsController' => 'applications/meta/controller/PhabricatorApplicationEmailCommandsController.php',
+    'PhabricatorApplicationMailReceiver' => 'applications/metamta/receiver/PhabricatorApplicationMailReceiver.php',
     'PhabricatorApplicationObjectMailEngineExtension' => 'applications/transactions/engineextension/PhabricatorApplicationObjectMailEngineExtension.php',
     'PhabricatorApplicationPanelController' => 'applications/meta/controller/PhabricatorApplicationPanelController.php',
     'PhabricatorApplicationPolicyChangeTransaction' => 'applications/meta/xactions/PhabricatorApplicationPolicyChangeTransaction.php',
@@ -5852,7 +5853,7 @@ phutil_register_library_map(array(
     'DifferentialCreateCommentConduitAPIMethod' => 'DifferentialConduitAPIMethod',
     'DifferentialCreateDiffConduitAPIMethod' => 'DifferentialConduitAPIMethod',
     'DifferentialCreateInlineConduitAPIMethod' => 'DifferentialConduitAPIMethod',
-    'DifferentialCreateMailReceiver' => 'PhabricatorMailReceiver',
+    'DifferentialCreateMailReceiver' => 'PhabricatorApplicationMailReceiver',
     'DifferentialCreateRawDiffConduitAPIMethod' => 'DifferentialConduitAPIMethod',
     'DifferentialCreateRevisionConduitAPIMethod' => 'DifferentialConduitAPIMethod',
     'DifferentialCustomField' => 'PhabricatorCustomField',
@@ -6704,7 +6705,7 @@ phutil_register_library_map(array(
     'FeedStoryNotificationGarbageCollector' => 'PhabricatorGarbageCollector',
     'FileAllocateConduitAPIMethod' => 'FileConduitAPIMethod',
     'FileConduitAPIMethod' => 'ConduitAPIMethod',
-    'FileCreateMailReceiver' => 'PhabricatorMailReceiver',
+    'FileCreateMailReceiver' => 'PhabricatorApplicationMailReceiver',
     'FileDeletionWorker' => 'PhabricatorWorker',
     'FileDownloadConduitAPIMethod' => 'FileConduitAPIMethod',
     'FileInfoConduitAPIMethod' => 'FileConduitAPIMethod',
@@ -7232,7 +7233,7 @@ phutil_register_library_map(array(
     ),
     'ManiphestConstants' => 'Phobject',
     'ManiphestController' => 'PhabricatorController',
-    'ManiphestCreateMailReceiver' => 'PhabricatorMailReceiver',
+    'ManiphestCreateMailReceiver' => 'PhabricatorApplicationMailReceiver',
     'ManiphestCreateTaskConduitAPIMethod' => 'ManiphestConduitAPIMethod',
     'ManiphestCustomField' => 'PhabricatorCustomField',
     'ManiphestCustomFieldNumericIndex' => 'PhabricatorCustomFieldNumericIndexStorage',
@@ -7679,7 +7680,7 @@ phutil_register_library_map(array(
     'PassphraseTokenCredentialType' => 'PassphraseCredentialType',
     'PasteConduitAPIMethod' => 'ConduitAPIMethod',
     'PasteCreateConduitAPIMethod' => 'PasteConduitAPIMethod',
-    'PasteCreateMailReceiver' => 'PhabricatorMailReceiver',
+    'PasteCreateMailReceiver' => 'PhabricatorApplicationMailReceiver',
     'PasteDefaultEditCapability' => 'PhabricatorPolicyCapability',
     'PasteDefaultViewCapability' => 'PhabricatorPolicyCapability',
     'PasteEditConduitAPIMethod' => 'PhabricatorEditEngineAPIMethod',
@@ -7740,6 +7741,7 @@ phutil_register_library_map(array(
     'PhabricatorApplicationEditHTTPParameterHelpView' => 'AphrontView',
     'PhabricatorApplicationEditor' => 'PhabricatorApplicationTransactionEditor',
     'PhabricatorApplicationEmailCommandsController' => 'PhabricatorApplicationsController',
+    'PhabricatorApplicationMailReceiver' => 'PhabricatorMailReceiver',
     'PhabricatorApplicationObjectMailEngineExtension' => 'PhabricatorMailEngineExtension',
     'PhabricatorApplicationPanelController' => 'PhabricatorApplicationsController',
     'PhabricatorApplicationPolicyChangeTransaction' => 'PhabricatorApplicationTransactionType',
@@ -11364,7 +11366,7 @@ phutil_register_library_map(array(
     'PonderQuestionAnswerWikiTransaction' => 'PonderQuestionTransactionType',
     'PonderQuestionCommentController' => 'PonderController',
     'PonderQuestionContentTransaction' => 'PonderQuestionTransactionType',
-    'PonderQuestionCreateMailReceiver' => 'PhabricatorMailReceiver',
+    'PonderQuestionCreateMailReceiver' => 'PhabricatorApplicationMailReceiver',
     'PonderQuestionEditController' => 'PonderController',
     'PonderQuestionEditEngine' => 'PhabricatorEditEngine',
     'PonderQuestionEditor' => 'PonderEditor',

src/applications/differential/mail/DifferentialCreateMailReceiver.php

@@ -1,15 +1,10 @@
 <?php
 
-final class DifferentialCreateMailReceiver extends PhabricatorMailReceiver {
+final class DifferentialCreateMailReceiver
+  extends PhabricatorApplicationMailReceiver {
 
-  public function isEnabled() {
-    return PhabricatorApplication::isClassInstalled(
-      'PhabricatorDifferentialApplication');
-  }
-
-  public function canAcceptMail(PhabricatorMetaMTAReceivedMail $mail) {
-    $differential_app = new PhabricatorDifferentialApplication();
-    return $this->canAcceptApplicationMail($differential_app, $mail);
+  protected function newApplication() {
+    return new PhabricatorDifferentialApplication();
   }
 
   protected function processReceivedMail(

src/applications/files/mail/FileCreateMailReceiver.php

@@ -1,15 +1,10 @@
 <?php
 
-final class FileCreateMailReceiver extends PhabricatorMailReceiver {
+final class FileCreateMailReceiver
+  extends PhabricatorApplicationMailReceiver {
 
-  public function isEnabled() {
-    $app_class = 'PhabricatorFilesApplication';
-    return PhabricatorApplication::isClassInstalled($app_class);
-  }
-
-  public function canAcceptMail(PhabricatorMetaMTAReceivedMail $mail) {
-    $files_app = new PhabricatorFilesApplication();
-    return $this->canAcceptApplicationMail($files_app, $mail);
+  protected function newApplication() {
+    return new PhabricatorFilesApplication();
   }
 
   protected function processReceivedMail(

src/applications/maniphest/mail/ManiphestCreateMailReceiver.php

@@ -1,15 +1,10 @@
 <?php
 
-final class ManiphestCreateMailReceiver extends PhabricatorMailReceiver {
+final class ManiphestCreateMailReceiver
+  extends PhabricatorApplicationMailReceiver {
 
-  public function isEnabled() {
-    return PhabricatorApplication::isClassInstalled(
-      'PhabricatorManiphestApplication');
-  }
-
-  public function canAcceptMail(PhabricatorMetaMTAReceivedMail $mail) {
-    $maniphest_app = new PhabricatorManiphestApplication();
-    return $this->canAcceptApplicationMail($maniphest_app, $mail);
+  protected function newApplication() {
+    return new PhabricatorManiphestApplication();
   }
 
   protected function processReceivedMail(

src/applications/metamta/receiver/PhabricatorApplicationMailReceiver.php

@@ -0,0 +1,34 @@
+<?php
+
+abstract class PhabricatorApplicationMailReceiver
+  extends PhabricatorMailReceiver {
+
+  abstract protected function newApplication();
+
+  final public function isEnabled() {
+    return $this->newApplication()->isInstalled();
+  }
+
+  final public function canAcceptMail(PhabricatorMetaMTAReceivedMail $mail) {
+    $application = $this->newApplication();
+    $viewer = $this->getViewer();
+
+    $application_emails = id(new PhabricatorMetaMTAApplicationEmailQuery())
+      ->setViewer($viewer)
+      ->withApplicationPHIDs(array($application->getPHID()))
+      ->execute();
+
+    foreach ($mail->newTargetAddresses() as $address) {
+      foreach ($application_emails as $application_email) {
+        $create_address = $application_email->newAddress();
+        if (PhabricatorMailUtil::matchAddresses($create_address, $address)) {
+          $this->setApplicationEmail($application_email);
+          return true;
+        }
+      }
+    }
+
+    return false;
+  }
+
+}

src/applications/metamta/receiver/PhabricatorMailReceiver.php

@@ -16,28 +16,6 @@ abstract class PhabricatorMailReceiver extends Phobject {
 
   abstract public function isEnabled();
   abstract public function canAcceptMail(PhabricatorMetaMTAReceivedMail $mail);
-  final protected function canAcceptApplicationMail(
-    PhabricatorApplication $app,
-    PhabricatorMetaMTAReceivedMail $mail) {
-
-    $application_emails = id(new PhabricatorMetaMTAApplicationEmailQuery())
-      ->setViewer($this->getViewer())
-      ->withApplicationPHIDs(array($app->getPHID()))
-      ->execute();
-
-    foreach ($mail->newTargetAddresses() as $address) {
-      foreach ($application_emails as $application_email) {
-        $create_address = $application_email->newAddress();
-        if (PhabricatorMailUtil::matchAddresses($create_address, $address)) {
-          $this->setApplicationEmail($application_email);
-          return true;
-        }
-      }
-    }
-
-    return false;
-  }
-
 
   abstract protected function processReceivedMail(
     PhabricatorMetaMTAReceivedMail $mail,

src/applications/paste/mail/PasteCreateMailReceiver.php

@@ -1,15 +1,10 @@
 <?php
 
-final class PasteCreateMailReceiver extends PhabricatorMailReceiver {
+final class PasteCreateMailReceiver
+  extends PhabricatorApplicationMailReceiver {
 
-  public function isEnabled() {
-    $app_class = 'PhabricatorPasteApplication';
-    return PhabricatorApplication::isClassInstalled($app_class);
-  }
-
-  public function canAcceptMail(PhabricatorMetaMTAReceivedMail $mail) {
-    $paste_app = new PhabricatorPasteApplication();
-    return $this->canAcceptApplicationMail($paste_app, $mail);
+  protected function newApplication() {
+    return new PhabricatorPasteApplication();
   }
 
   protected function processReceivedMail(

src/applications/ponder/mail/PonderQuestionCreateMailReceiver.php

@@ -1,15 +1,10 @@
 <?php
 
-final class PonderQuestionCreateMailReceiver extends PhabricatorMailReceiver {
+final class PonderQuestionCreateMailReceiver
+  extends PhabricatorApplicationMailReceiver {
 
-  public function isEnabled() {
-    $app_class = 'PhabricatorPonderApplication';
-    return PhabricatorApplication::isClassInstalled($app_class);
-  }
-
-  public function canAcceptMail(PhabricatorMetaMTAReceivedMail $mail) {
-    $ponder_app = new PhabricatorPonderApplication();
-    return $this->canAcceptApplicationMail($ponder_app, $mail);
+  protected function newApplication() {
+    return new PhabricatorPonderApplication();
   }
 
   protected function processReceivedMail(