Yes. Claude has worked on the deprecation in
https://github.com/django/django/pull/3220 but it requires adding more
migrations to our test suite and he noted that each migration we add to
Django's test suite adds up to ~3.5 seconds to the run time of the test
suite. He also worked on some speed ups to mitigate this in
https://github.com/django/django/pull/3484 but there are some unsolved
issues.
On Friday, December 19, 2014 11:03:04 AM UTC-5, Andrew Godwin wrote:
>
> Hi Tim,
>
> I can have a look, but I can't be certain about hitting any deadlines. I
> do want to get that deprecation in, though...
>
> Did you want it with a view to us being able to drop that in for tests
> rather than making migrations for every test app, I presume?
>
> Andrew
>
> On Fri, Dec 19, 2014 at 3:06 PM, Tim Graham <timog...@gmail.com
> <javascript:>> wrote:
>>
>> Andrew, I've thought of something similar to the in-memory migrations
>> idea you've proposed. It would be great not to have to add and maintain
>> migrations for all of the apps in Django's test suite. Do you think you
>> might be able to investigate this solution in the next month or so before
>> 1.8 alpha? I think we need a solution in 1.8 if we are to complete #22340 -
>> Legacy
>> Table Creation Methods Not Properly Deprecated (otherwise, we can again
>> postpone that deprecation).
>>
>> On Friday, December 19, 2014 8:17:05 AM UTC-5, Andrew Godwin wrote:
>>>
>>> I agree that migrations are slower than syncdb - that's perhaps the only
>>> thing worse about them - but the reason we plan to deprecate the other
>>> methods is code simplicity; migrations does not share almost any code with
>>> the old DatabaseCreation backends, and if we don't deprecate it we're going
>>> to end up maintaining two creation backends for every database driver,
>>> which isn't going to go well.
>>>
>>> There's perhaps something to be said for an option where tests make an
>>> in-memory set of migrations from the autodetector and an empty state and
>>> run them immediately - somewhat replicating the syncdb process while still
>>> using the same code paths - but I haven't had the time to investigate how
>>> well this would work yet (there are some migration decisions that would
>>> need defaults inserted).
>>>
>>> I think the end result would be an alternative test runner that you
>>> could switch to if you wanted this behaviour (and a mixin with the actual
>>> logic or something similar so it's easy to incorporate into other test
>>> runners).
>>>
>>> Andrew
>>>
>>> On Wed, Dec 17, 2014 at 6:59 PM, <c...@epantry.com> wrote:
>>>
>>>> At the risk of reviving an old topic, I wanted to add one significant
>>>> point in favor of (and mitigation for) running tests with migrations
>>>> disabled: Speed.
>>>>
>>>> Creating a test DB in sqlite for our project (~100 database tables)
>>>> takes approximately 1-2 minutes on most developer machines. 1-2
>>>> minutes of idle time to run any test was just unacceptable so we disabled
>>>> migrations by setting fake migrations in MIGRATION_MODULES and brought the
>>>> test DB creation time down to about 5 seconds (!!).
>>>>
>>>> However the risk of committing invalid code because someone forgot to
>>>> makemigrations is real. We've addressed it by only overriding migrations
>>>> on
>>>> our local test settings and still having migrations run on our CI server.
>>>> We have our CI server use settings.test, while developers running tests on
>>>> their local machine use settings.test_local which is just:
>>>>
>>>> from settings.test import *
>>>>
>>>> MIGRATION_MODULES = ((app, '%s.fake_migrations' % app) for app in
>>>> INSTALLED_APPS)
>>>>
>>>>
>>>> This seems to get us the best of both worlds. I was surprised to read
>>>> through this thread and not see other mentions of the performance
>>>> implications of running migrations on every test run. I'd be curious to
>>>> hear if this has been a bottleneck for other teams.
>>>>
>>>> -Chris
>>>>
>>>> On Tuesday, March 25, 2014 10:21:51 AM UTC-7, Bernie Sumption wrote:
>>>>
>>>>> Hi Django devs,
>>>>>
>>>>> I've just started a new project in 1.7b, and the development
>>>>> experience working with unit tests on models is more complicated than it
>>>>> was in 1.6. It's all down to how the throwaway test databases are
>>>>> created.
>>>>> In 1.6, the create_test_db function "Creates a new test database and runs
>>>>> syncdb against it." In 1.7, it runs "migrate".
>>>>>
>>>>> While generally speaking, migrate is the new syncdb, this behaviour is
>>>>> not ideal for tests. In 1.6 "syncdb" created a database reflecting the
>>>>> current state of the models in models.py. "migrate" creates a database
>>>>> reflecting the state of the models at the last time makemigrations was
>>>>> run.
>>>>> If you're doing TDD and constantly making small changes to your models
>>>>> then
>>>>> runnning unit tests, you have to run makemigrations before each test run
>>>>> to
>>>>> get your tests to work. You therefore end up with many tiny migration
>>>>> files
>>>>> representing the minute-by-minute history of development.
>>>>>
>>>>> I came up with a pretty effective workaround that is working for me,
>>>>> but I thought I'd post this here as others are sure to encounter this
>>>>> issue, and I think that it makes more sense for the behaviour produced by
>>>>> this workaround to be the default for running tests.
>>>>>
>>>>> If makemigrations has not yet been run, the "migrate" command treats
>>>>> an app as unmigrated, and creates tables directly from the models just
>>>>> like
>>>>> syncdb did in 1.6. I defined a new settings module just for unit tests
>>>>> called "settings_test.py", which imports * from the main settings module
>>>>> and adds this line:
>>>>>
>>>>> MIGRATION_MODULES = {"myapp": "myapp.migrations_not_used_in_tests"}
>>>>>
>>>>> Then I run tests like this:
>>>>>
>>>>> DJANGO_SETTINGS_MODULE="myapp.settings_test" python manage.py test
>>>>>
>>>>> This fools migrate into thinking that the app is unmigrated, and so
>>>>> every time a test database is created it reflects the current structure
>>>>> of
>>>>> models.py.
>>>>>
>>>>> So my feature request is as follows:
>>>>>
>>>>> If the new behaviour is by design and considered desirable, then it is
>>>>> a big change from the previous version and should be prominently
>>>>> documented
>>>>> in the migrations and testing pages, along with the workaround. I'm happy
>>>>> to write this documentation if that's the way you want to go.
>>>>>
>>>>> However, if the new behaviour is not by design but just a by-product
>>>>> of the new migrations feature, I suggest making the workaround the
>>>>> default
>>>>> behaviour. I don't (yet!) know enough about Django internals to volunteer
>>>>> for this however.
>>>>>
>>>>> Thanks for your time,
>>>>>
>>>>> Bernie :o)
>>>>>
>>>>> --
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