add mongomock if app.config['TESTING']

[ocean1]

i would love to be able to have a mongomock connection if app.config['TESTING'] is true
this would allow easier testing of the flask application (otherwise an in-memory mongo like the one implemented in ming would be great)

[aviau]

+1

[sri85]

+1

[brunobelarmino]

+1

[losintikfos]

I will be looking into adding this to the milestone.

Thanks

[losintikfos]

Target

• Create a temporary mongod instance for testing purposes only. The presence of setting app.config['TESTING'] will instruct Flask-MongoEngine bootstrap to provide temporary mongod instance else a valid instance connection is established and provided instead.

[brunobelarmino]

@losintikfos why not use mongomock like mongo engine?
I think the best solution is change the "_create_connection" method of flask-mongoengine to not call pymongo "uri_parser.parse_uri" method when it contains the protocol: "mongomock://" like the mongoengine team has done (MongoEngine/mongoengine@23f07fd).

The problem is the current version of mongo engine (0.10.5) doens't support it yet. But the next version (0.10.6) will.

What do you think about?

[losintikfos]

@brunobelarmino so similarly to MongoEngine - check for the connection string protocol construct instead of the app.config['TESTING'] setting?

[brunobelarmino]

@losintikfos IMHO it is the better solution. 😄

let me know yours.

[losintikfos]

@brunobelarmino I did not patronise nor pooped your suggestion. I was enquiring for confirmation to ensure you meant avoid using setting app.config['TESTING'], but instead check for the connection string protocol construct.

Your solution might be best to you but not to others.

[brunobelarmino]

Sorry whether my message seems selfish. But it isnt the intention.

I think flask-mongoengine shouldnt decide whats the best way to test apps. For example: create a mongod instance, use a existing mongod instance or use mongomock.

I think the best solution is turn flask-mongoengine flexible and working with all this approaches.

But my point is today flask-mongoengine doesnt work with mongomock. I Think when the app.config['TESTING'] is true we could by pass de pymongo uri validation. Additionally would be nice have a default approach to use when neither of the others is defined.

[losintikfos]

@brunobelarmino agree +1

[lafrech]

Fixed in master. @brunobelarmino, @ocean1, time to give it a try before the release ships.

[the-jake-z]

Is there any word for adding back support for MongoMock in? I saw it was removed in 2bb06df, but for a lot of people this could be a deal breaker for using flask and mongo who want to write good unittests.

[LaundroMat]

Hi @jzarob - I've been able to get things to work with pytest, flask-mongoengine and mongomock by adding this to my conftest.py

@pytest.fixture
def app():
    os.environ["MONGO_DB"] = "test"
    os.environ["MONGO_URI"] = 'mongomock://localhost'

    app = create_app()
    return app

This overloads the environment settings for when flask_mongo_engine.MongoEngine(app) is called in create_app(). (Of course, I'm assuming that your create_app() gets its settings from environment variables, like mine does).

[claradaia]

Hi @LaundroMat, could you provide more details? Perhaps your create_app code?

[LaundroMat]

Well, the only relevant code in create_app() is

    app = Flask(__name__)
    app.config['SECRET_KEY'] = os.getenv('SECRET_KEY')
    csrf = CSRFProtect(app)
    app.config['MONGODB_SETTINGS'] = {
        'db': os.getenv('MONGO_DB'),
        'host': os.environ['MONGO_URI']
    }
    app.config['MONGODB_CONNECT'] = False  # open connection only on first database access
    db = MongoEngine(app)

You also need to include app as a parameter to every test function that touches the database. E.g.

def test_create_model_instance(app):    # <- by including app, you're using the conftest app and thereby overriding the normal db connection
    # your test code.

[claradaia]

Thank you, @LaundroMat! Turns out my problem was I had not imported the main 'app' nor included the fixture as a parameter like you mentioned, so the database was never configured.

[thmsklngr]

Hi,
I'm just a newbie using pytest for testing my code. Is there any full code example out there to see how a combination Flask/MongoEngine/mongomock could work? Snippets are not so meaningful to me, unfortunately.
Many thanks in advance for any answer, regards, Thomas