[wp-trac] [WordPress Trac] #28618: Allow PHPMailer class to be reliably overriden

[WordPress Trac]

#28618: Allow PHPMailer class to be reliably overriden
-------------------------------------------------+-------------------------
 Reporter:  leewillis77                          |       Owner:  (none)
     Type:  defect (bug)                         |      Status:  new
 Priority:  normal                               |   Milestone:  Future
                                                 |  Release
Component:  Mail                                 |     Version:  4.0
 Severity:  normal                               |  Resolution:
 Keywords:  needs-patch needs-unit-tests good-   |     Focuses:
  first-bug has-test-info                        |
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Changes (by SirLouen):

 * keywords:  has-patch has-unit-tests close reporter-feedback => needs-
     patch needs-unit-tests good-first-bug has-test-info
 * type:  enhancement => defect (bug)


Comment:

 Ok, after doing a little more research, yes I could reproduce this in a
 single test, but I could not reproduce in a plugin as the reporter
 suggested, because tests run in a different DB, and there should not be
 any `active_plugins` in the `wp_options` table by default unless we are
 doing something very wrong. This plugin thing was misdirecting my
 attention.

 But now I've been looking into how the `tear_down` in `wpMail` is running
 the `reset_phpmailer_instance`.

 The reality is that, if we test this way:

 {{{
 /**
  * @group sample
  */
 public function test_unsetting_phpmailer_instance() {
         global $phpmailer;
         $phpmailer = null;
         $this->assertNull( $phpmailer );
 }
 /**
  * @group sample
  */
 public function test_random_delivery() {
         wp_mail( 'test at example.com', 'Test', 'Test' );
         global $phpmailer;
         $this->assertInstanceOf( 'MockPHPMailer', $phpmailer );
 }
 }}}

 The PHPMailer instance is not being completely reset in `tear_down` in
 `reset_phpmailer_instance` and the email is being sent with a regular
 PHPMailer object.

 This section of code is not doing the job:

 https://github.com/WordPress/wordpress-
 develop/blob/3ea6be9fa8a4973c2b01c094f062de4fd33c0aba/tests/phpunit/includes
 /mock-mailer.php#L110-L123

 The problem is that the `$mailer` conditional is not covering the scenario
 where `$phpmailer` is unset.

 This was addressed in [41185], but was not sufficiently addressed, not
 covering this edge case. What I'm trying to devise is why the conditional
 was introduced first in [37358].

 I think that the object should be reset unconditionally. I would like to
 see a patch proposal.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/28618#comment:8>
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