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Testing the ravens

Exercise 5 of 6 in chapter 7 · 260 XP · 5 objectives checked by tests

Topics covered: Testing messagesIn-memory queueWorker

The aviary works. Now you need to make sure it will still work in six months, when Pippin has “tidied up” the configuration.

Testing messages calls for a bit of method: the work no longer happens during the request. A test that only looks at the final result would not see the difference between “handled in the background” and “handled right away”.

Your mission

In tests/Taverne/CorbeauxTest.php, write the tests for the whole chain:

  1. a reservation puts a message in the queue, and does not send any raven right away;
  2. when the queue is handled, the raven leaves, with the right message;
  3. an impossible delivery (Sauron) is retried, then set aside in the failure queue;
  4. the evening summary only counts tomorrow's tables.

Your tools

The FileDeMessages trait (message queue), already provided:

$this->messagesEnFile();          // the messages waiting in the queue ("async" transport)
$this->messagesEnFile('echoues'); // the ones that were set aside
$this->consommerLaFile();         // handles the queue, and returns the number of messages handled
$this->lancerLeWorker();          // a real worker: retries and failure queue included

consommerLaFile() (consume the queue) is enough for the normal case. To observe a failure, you need a real worker (lancerLeWorker(), start the worker): its retries are what end up setting the message aside.

How you're graded

Same as in the previous chapter: your tests must pass on the aviary as it is, then fail on each of the four mutants 🐛. A mutant that survives means a missing test.