Flexible matching for eg SubjectSpecification

[xurizaemon]

I have a site which sends emails with subject like "Your order 123 is confirmed" and would like to test for presence of the order confirmation email using rpkamp/mailhog-behat-extension; in order to simplify tests, I'd like to use a loose match such as "Your order * is confirmed".

Current behaviour for the following appears to be:

Then I should see an email with subject "subject" and body "body" to "[email protected]"

• subject match is exact (===)
• body match uses strpos to test for string presence
• recipient match is any (contains)

I see that matching implementations vary:

https://github.com/rpkamp/mailhog-client/blob/a93d089d2d88aeb5b3095ae61987da609d8ed940/src/Specification/SubjectSpecification.php#L20-L23

https://github.com/rpkamp/mailhog-client/blob/a93d089d2d88aeb5b3095ae61987da609d8ed940/src/Specification/SenderSpecification.php#L21-L24

https://github.com/rpkamp/mailhog-client/blob/a93d089d2d88aeb5b3095ae61987da609d8ed940/src/Specification/BodySpecification.php#L22-L25

https://github.com/rpkamp/mailhog-client/blob/a93d089d2d88aeb5b3095ae61987da609d8ed940/src/Specification/RecipientSpecification.php#L21-L24

https://github.com/rpkamp/mailhog-client/blob/a93d089d2d88aeb5b3095ae61987da609d8ed940/src/Specification/AttachmentSpecification.php#L20-L29

One approach would be that the looser specification apply (eg subject, recipient, body all are "contains" type implementations). Alternatively we could introduce a way to flag specification matches for the new looser behaviour, to preserve BC better.

I've opened this in rpkamp/mailhog-client as I believe that's the right place for it, but let me know if I'm missing a trick over in rpkamp/mailhog-behat-extension!

[rpkamp]

That's a good point and something to be expanded upon in the future! I don't want to add that now in haste, but rather chew on it a bit to get it right.

In the meantime you could quite easily add your own Specification and Behat Context.

SubjectMatchesSpecification

final class SubjectMatchesSpecification implements Specification
{
   /**
    * @var string
    */
    private $regex;
      
    public function __construct(string $regex)
    {
        $this->regex = $regex;
    }
    
    public function isSatisfiedBy(Message $message): bool
    {
        return preg_match($this->regex, $message->subject);
     }
}

MessageMatchingContext.php

<?php
declare(strict_types=1);

use rpkamp\Mailhog\MailhogClient;
use rpkamp\Behat\MailhogExtension\Context\MailhogAwareContext;

class FeatureContext implements MailhogAwareContext
{
    private $mailhog;
    
    public function setMailhog(MailhogClient $client)
    {
         $this->mailhog = $client;
    }

    /**
     * @Then /^I should see an email where subject matches "([^"]+)"$/
     */
    public function iShouldSeeAnEmailWhereSubjectMatches(string $regex): void
    {
        $messages = $this->mailhogClient->findMessagesSatisfying(new SubjectMatchesSpecification($regex));

        if (count($message) > 0) {
            return;
        }

        // throw exception
    }
}

With that you can use the step like so

Then I should see an email where subject matches "Your order \d is confirmed"

As a general approach though, I would always suggest wiping the database before any actions like these, so the number in the email becomes predictable and you can directly check against it.