Same mailer instance being returned regardless of which request is passed to get_mailer

[pyramidX]

In a given unit test function I create 2 requests, each send one email. Even though I'm passing 2 different instances of DummyRequest to get_mailer, the DummyMailer objects returned are the same instance. You can see in my last assert statement it fails because there are 2 emails in the outbox (one created by request1 and the other by request2).

I can do a mailer1.outbox.clear() to get the expected behavior. But is this the right way of doing this? How come get_mailer behaves like this, returning the same instance every time?

request1 = testing.DummyRequest(...)
views.send_one_email(...)
mailer1 = get_mailer(request1)

# mailer1.outbox.clear()  # Why is this necessary for the last assert below not to fail?

request2 = testing.DummyRequest(...)
views.send_one_different_email(...)
mailer2 = get_mailer(request2)

assert request1 is not request2  # Not the same request instances
assert mailer1 is mailer2  # It's the same mailer instance
assert len(mailer1.outbox) == 1
assert len(mailer2.outbox) == 1  # Fails

It works the same if I do it like this, which wouldn't make me think there will be 2 different mailers returned, but in this case what's the purpose of passing a DummyRequest to get_mailer?

single_mailer = get_mailer(testing.DummyRequest())

request1 = testing.DummyRequest(...)
views.send_one_email(...)

request2 = testing.DummyRequest(...)
views.send_one_different_email(...)

assert request1 is not request2  # Not the same request instances
assert len(single_mailer.outbox) == 1
assert len(single_mailer.outbox) == 1  # Fails

[Tres Seaver]

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On 12/22/2014 03:04 PM, pyramidX wrote:
> It works the same if I do it like this, which wouldn't make me think
> there will be 2 different mailers returned, but in this case what's
> the purpose of passing a DummyRequest to get_mailer?

The mailer is a "utility" (a singleton), registered in 'request.registry'.


Tres.
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===================================================================
Tres Seaver +1 540-429-0999 tse...@palladion.com
Palladion Software "Excellence by Design" http://palladion.com
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[Michael Merickel]

The mailer is a utility that represents an external service. It is not
different per-request just like how your smtp server is not different
per email you send.

Using .clear() is appropriate here.

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[Jonathan Vanasco]

On Monday, December 22, 2014 3:40:11 PM UTC-5, Tres Seaver wrote:

The mailer is a "utility" (a singleton), registered in 'request.registry'.

Just to expand on this answer a bit...

The mailer is designed to be configured-for and associated-with the scope of an application -- not each individual request. 

[pyramidX]

I see, I'm accessing it now with

mailer = config.registry.getUtility(IMailer)

which definitely gives it more of an utility kind of feel. Thanks!