django-email-extras Add tests

Should be applied after/on top of #39. I will rebase this on top of master once that gets merged in.

The first six commits are from #39.

TODO:

[x] Fix some bugs uncovered by tests
[x] Add tests for email_extras.utils.send_mail function
[x] Add tests for the model save() and delete() functions
[x] Add tests for the encrypting backend from #39
[x] Add tests BrowsableEmailBackend
[x] Add tests for has_add_permission on Address admin
[x] Improve coverage for existing test cases (key.email_addresses property)
[x] Add tests for signing outgoing mail
[x] Add tests for management command
[x] Add tests for forms
[x] Add tests for default exception handlers, and tests to make sure custom exception handlers are called
[x] Figure out what the behavior should be when ALWAYS_TRUST is False and add tests for that ~~- is this even useful? Everything broke when I turned that off...~~ Test for this added from @theithec's comment
[x] Add Travis CI integration
[x] Add flake8 check
[x] Add Travis build status badge and Coveralls coverage status badge to README

~~There's only one line of crypto code that isn't tested: email_extras/backends.py:72~~

This PR now has 100% test coverage for django-email-extras!

Further work for future PRs:

Add create, update, and delete functions to the queryset on the models so queryset functions operate the same way model functions do
Move the save() and delete() functions from the models into their own pre_save, post_save, and pre_delete signal handlers and wire them up in email_extras/apps.py. This should allow us to use serialized fixtures in tests.
Make the models swappable

Mar 30 '17 12:03 blag

I think this is really cool. Both, the tests and the backends. Maybe the tests should live in email_extras, so they would be available to anyone who installed the package. In that case, GNUPG_HOME should be hardcoded in tests.utils and the gpg_keyring directory could move into tests. And the tests would have to make sure to set email_extras.utils.encrypt_kwargs['always_trust'] is True.

I don't like encrypt_kwargs in settings that much. Maybe utils would be a better place do define it?
And the code duplication in utils and backend should be removed somehow.

Here is a test that could be added:

# tests/utils.py
# import email_extras.utils

def test_send_mail_key_validation_fail_raises_exception(self):
    msg_subject = "Test Subject"
    to = ['[email protected]']
    from_email = settings.DEFAULT_FROM_EMAIL
    msg_text = "Test Body Text"
    msg_html = "<html><body><b>Hello</b> World <i>Text</i>"

    email_extras.utils.encrypt_kwargs['always_trust'] = False
    with self.assertRaises(email_extras.utils.EncryptionFailedError):
        self.send_mail(
            msg_subject, msg_text, from_email, to,
            html_message=mark_safe(msg_html))
    email_extras.utils.encrypt_kwargs['always_trust'] = True

Mar 30 '17 19:03 theithec

@theithec Thanks for the review. I rewrote the backend (removed admin page and added a management command to generate/upload signing keys), and I'll be rebasing this off of that and adding your test this weekend.

Travis CI results (add-tests branch): Coveralls results:

Mar 31 '17 23:03 blag

Aside from getting this reviewed (and any changes that I'll make from that), this is done. It's got 97% overall coverage, and 99% coverage for the crypto code. The only line of crypto code that isn't tested is the second encryption failure test for the backend:

def encrypt(text, addr):
    encryption_result = gpg.encrypt(text, addr, **encrypt_kwargs)
    if not encryption_result.ok:
        raise EncryptionFailedError("Encrypting mail to %s failed: '%s'",
                                    addr, encryption_result.status)
    if smart_text(encryption_result) == "" and text != "":  # <-- THIS LINE
        raise EncryptionFailedError("Encrypting mail to %s failed.",
                                    addr)
    return smart_text(encryption_result)

Apr 03 '17 14:04 blag

Rebasing on master now that #41 is merged...

Apr 09 '17 23:04 blag

Done rebasing.

Apr 09 '17 23:04 blag

This PR just hit 100% coverage for all code!

I did skip coverage for the following lines. They are either not mission critical (testing body_html and html_message aren't both passed to send_mail, ImportError in email_extras/settings.py), are pretty much guaranteed to work properly (the AppConfig.ready() function being called), or would have permanent, irreversible, global side effects we don't want (gpg.send_keys()).

email_extras/apps.py:11

    def ready(self):  # pragma: noqa

email_extras/management/commands/email_signing_key.py:21

    gpg.send_keys(keyservers, fingerprint)  # pragma: nocover

email_extras/settings.py:31

    except ImportError:  # pragma: no cover

email_extras/utils.py:82,87

    if body_html is not None and html_message is not None:  # pragma: no cover

    if body_html is not None:  # pragma: no cover

Now that this has hit 100%, I'll stop tweaking it. So @theithec if you want to review it again, I would appreciate it. I know that @stephenmcd has a lot of stuff going on at the moment.

Apr 10 '17 18:04 blag