[Flask] Flask-sqlalchemy and testing

[Samuel Freeman]

Hello,
Thanks both for the above, helps towards my understanding of how some of
these things work : )

with apologies for going a bit off topic, it was Gabor's final comment that
sparked my reply - I also hope to oneday figure out how/why the different
patterns work

I have never found the
    Counter.query.all()
way of calling to work in my apps, instead relying on the
    db.session.query(Counter).all()
way...

I made the following util function to help me be less annoyed about it, but
it seems not very pythonic to hide the details in this way:
```
def db_q(what):
    return db.session.query(what)
```
>>> db_q(Counter).all()

I also struggle to get tests working most of the time, again because I am
yet to understand some of the patterns involved.

Samuel

On Fri, 14 May 2021 at 06:04, Gabor Szabo <gabor at szabgab.com> wrote:

> I've solved most of the issues in the second example though I still have
> to write
>     db.session.query(Counter).all()
> instead of the much nicer
>     Counter.query.all()
> but maybe one day I'll figure that out too.
>
> Gabor
>
> On Thu, May 13, 2021 at 4:57 PM Gabor Szabo <gabor at szabgab.com> wrote:
>
>> Nicolas, thanks. That helped a lot and I managed to write a full example
>> that shows this: https://code-maven.com/flask-counter-sqlite-sqlalchemy
>>
>>
>> However I still have an issue. We use yoyo to manage migrations and I
>> wanted to try the automap feature of SQLAlchemy.  I could not solve it
>> elegantly just this way:
>> https://code-maven.com/flask-counter-sqlite-sqlalchemy-yoyo
>>
>> * There is a "global" in the model.py
>> * I could not figure out how to create the classes for the table(s) so I
>> added them to a "base" class.
>> * I had to change the query code from Counter.query.all()
>>
>> Any suggestions there?
>>
>> Gabor
>>
>> On Wed, May 12, 2021 at 12:12 PM Nicolas Le Manchet <nicolas at lemanchet.fr>
>> wrote:
>>
>>> Hi,
>>>
>>> You should take a look at application factories (
>>> https://flask.palletsprojects.com/en/1.1.x/patterns/appfactories/).
>>> It's a pattern that allows to have multiple applications configured
>>> differently in the same interpreter, which tends to make testing easier.
>>>
>>> On Wed, May 12, 2021, at 11:00, Gabor Szabo wrote:
>>> > Hi,
>>> >
>>> > I am working on an application using Flask-sqlalchemy and I am not
>>> sure
>>> > how to write tests properly.
>>> >
>>> > In all the examples I have seen so far the main flask file has the line
>>> >
>>> >     db = SQLAlcehmy(app)
>>> >
>>> > meaning this is executed when the main file of Flask is loaded. so if
>>> > the test file has
>>> >
>>> >     import app
>>> >
>>> > that would still happen at compile time. This way I have only one
>>> > chance to set up a test-database , right before that import-statement.
>>> >
>>> > In order to make it easier to use different test database we moved the
>>> >     db = SQLAlcehmy(app)
>>> > call inside a function decorated with before_first_request.
>>> > This ensures the code is called for regular use and we can call the
>>> > before_first_request method for each test. Because we don't have db at
>>> > load time we also had to move all the class-declarations in this
>>> > function (because they all inherit from db.Model).
>>> >
>>> > The problem is that now all the model classes are scoped to this
>>> > function. We had to use "global" to make them accessible to the rest
>>> of
>>> > the code.
>>> >
>>> > That does not look right.
>>> >
>>> > The code can be found here: https://github.com/rnewstead1/workout-app/
>>> > (together with the tests)
>>> > And you can actually see our struggle in this video:
>>> > https://code-maven.com/workout-app-2
>>> >
>>> > I'd appreciate your insight on how to make this nicer or even just a
>>> > link to a code-base that has such tests.
>>> >
>>> > Gabor
>>>
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