I have an app.py file which creates an flask app
def create_app():
app = Flask(__name__)
return app
I am trying to write an unittest for my module and below is the file
from app import create_app
class TestCase(unittest.TestCase):
def setUp(self):
self.app = create_app()
self.client = self.app.test_client()
ctx = self.app.app_context()
ctx.push()
def test_healthcheck(self):
res = self.client.get("/")
self.assertEqual(res.status_code, 200)
def test_tenant_creation(self):
res = self.client.post("/tenants")
self.assertEqual(res.status_code, 200)
When i run individual test methods it is working fine. But when i run the entire test case , the create app is called again which causes issues since my create app has dependencies which needs to be called only once.
Is it possible to create app only once ?
setUp gets called before each test method. Therefore, if you run the whole test case, it will be called twice (one for each test method).
To run something only once for the TestCase, you could try overriding the __init__ method (see this SO question), or setUpClass or setUpModule. YMMV depending on which python version and test runners you are using.
IMO, the problem may related with context. You should create a tearDown() method to destroy the application context you created in setUp():
class TestCase(unittest.TestCase):
def setUp(self):
self.app = create_app()
self.client = self.app.test_client()
self.ctx = self.app.app_context()
self.ctx.push()
def tearDown(self):
self.ctx.pop()
Related
I'm learning Flask and am a bit confused about how to structure my code. So I tried to extend Flask main class as follows:
from flask import Flask, ...
class App(Flask):
def __init__(self, import_name, *args, **kwargs):
super(App, self).__init__(import_name, *args, **kwargs)
Note that I am aware of that this may be a completely wrong approach.
So that when I want to start the app I do:
app = App(__name__)
if __name__ == '__main__':
app.run()
This way I can order my methods and routes in the class, but the problem is when using self-decorators:
#route('/')
def home(self, context=None):
context = context or dict()
return render_template('home.html', **context)
Which raises an error as unresolved reference 'route'. I guess this is not the way I should be structuring the app. How should I do it instead or how do I get the error fixed?
Doing this doesn't make sense. You would subclass Flask to change its internal behavior, not to define your routes as class methods.
Instead, you're looking for blueprints and the app factory pattern. Blueprints divide your views into groups without requiring an app, and the factory creates and sets up the app only when called.
my_app/users/__init__.py
from flask import Blueprint
bp = Blueprint('users', __name__, url_prefix='/users')
my_app/users/views.py
from flask import render_template
from my_app.users import bp
#bp.route('/')
def index():
return render_template('users/index.html')
my_app/__init__.py
def create_app():
app = Flask(__name__)
# set up the app here
# for example, register a blueprint
from my_app.users import bp
app.register_blueprint(bp)
return app
run.py
from my_app import create_app
app = create_app()
Run the dev server with:
FLASK_APP=run.py
FLASK_DEBUG=True
flask run
If you need access to the app in a view, use current_app, just like request gives access to the request in the view.
from flask import current_app
from itsdangerous import URLSafeSerializer
#bp.route('/token')
def token():
s = URLSafeSerializer(current_app.secret_key)
return s.dumps('secret')
If you really want to define routes as methods of a Flask subclass, you'll need to use self.add_url_rule in __init__ rather than decorating each route locally.
class MyFlask(Flask):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.add_url_rule('/', view_func=self.index)
def index(self):
return render_template('index.html')
The reason route (and self) won't work is because it's an instance method, but you don't have an instance when you're defining the class.
im using the unittest Framework to test my flask application. Since i have multiple Testcase classes i want to structure/refactor them.
BaseTest.py contains:
import unittest
from config import Config
from app import create_app, db
class TestConfig(Config):
""" overridden config for testing """
class TestInit(unittest.TestCase):
def setUp(self):
self.app = create_app(TestConfig)
self.app_context = self.app.app_context()
self.app_context.push()
self.app = self.app.test_client()
db.create_all()
def tearDown(self):
db.session.remove()
db.drop_all()
self.app_context.pop()
Then i try to have testcases in
ProjectTest.py:
from app.models import *
from tests.BaseTest import TestInit
class ProjectTest(TestInit):
def setUp(self):
super().setUp()
# create Test Data
proj1 = Project(
name='TestProject1',
project_state_id=1,
project_type_id=1
)
db.session.add(proj1)
db.session.commit()
for pro in Project.query.all():
print(pro)
def test_project_add(self):
pass
i get the error message:
ModuleNotFoundError: No module named 'tests.BaseTest'; 'tests' is not a package
I have all theses files in the folder tests and tried all variation on how to import it (even with a __init__.py file) but i always get the error.
if your source codes are in the same folder, you don't need to import tests.BaseTest
because interpreter shouldn't look anywhere else except current folder.
just importing BaseTest would be enough.
edited code would be:
from BaseTest import TestInit
I've got a Flask application which I'd like to run some unit tests on. To do so, I create a new Flask object, initialise blueprints, SQLA and a few other packages and execute the test case.
However, I've noticed that some endpoints on the test flask object are missing, which made me wonder about the general way of how initialisation is handled in flask.
Taking a minimal example, an endpoint would be created like so:
from flask import Flask
app = Flask(__name__)
#app.route('/')
def hello_world():
return 'Hello World!'
if __name__ == '__main__':
app.run()
If I was to create a new Flask object somewhere in my testcase's setUp method, it would most certainly not contain a route '/' as this route was created from another flask object (the one from the file above). So my question is: How should a test case be written and how is the initialisation meant to work in general? Somewhere I read that one should avoid initialisation at import (i.e. on a module level), but this seems to be impossible if annotations are used.
You don't create a new Flask object in your test cases. You import your existing app instead.
In many project setups you already added all your extensions to that app. In many of mine I have a factory method that'll take a configuration object and returns the fully initialized app object for me; I use this to create a base test case:
import unittest
import project
class Config(object):
DEBUG = False
TESTING = True
CACHE_NO_NULL_WARNING = True # silence Flask-Cache warning
SECRET_KEY = 'SECRET_KEY'
class ProjectCoreViewCase(unittest.TestCase):
"""Base test case for the Project core app"""
def setUp(self, **kwargs):
config = Config()
config.__dict__.update(kwargs)
app = project.create_app(config)
self.app = app.test_client()
and any tests can then use self.app as the test client in all tests.
This is a base test case, you'd inherit from it; the setUp() method allows for additional configuration to be set, by passing in keyword arguments to a super() call:
class ConcreteTestCase(ProjectCoreViewCase):
def setUp(self):
super(ConcreteTestCase, self).setUp(
SQLALCHEMY_DATABASE_URI='your_test_specific_connection_uri',
)
For every test I write that uses my apps models, I seem to have to use the current apps context:
SomeTestCase(unittest2.TestCase):
setUp(self):
self.app = Flask(__name__)
...
test_something(self):
with self.app.app_context():
# Do something
Is there a way to tell all of my tests to run using the current apps context to save me having this line in all of my tests?
I found the answer I was looking for by looking at the way the Flask-Testing extensions TestCase sets itself up, i.e., pushing the testing context to the _ctx stack inside a function that's called from within it's __call__ method.
class BaseTestCase(unittest2.TestCase):
def __call__(self, result=None):
try:
self._pre_setup()
super(BaseTestCase, self).__call__(result)
finally:
self._post_teardown()
def _pre_setup(self):
self.app = create_app()
self.client = self.app.test_client()
self._ctx = self.app.test_request_context()
self._ctx.push()
def _post_teardown(self):
if getattr(self, '_ctx') and self._ctx is not None:
self._ctx.pop()
del self._ctx
And my test:
class SomeTestCase(BaseTestCase):
test_something(self):
# Test something - we're using the right app context here
You can try something like below.
DISCLAIMER: I just came up with the idea and didn't test this solution thoroughly although it seems to work. It is also IMHO rather ugly.
from functools import wraps
def with_context(test):
#wraps(test)
def _with_context(self):
with self.app.app_context():
test(self)
return _with_context
SomeTestCase(unittest2.TestCase):
setUp(self):
self.app = Flask(__name__)
...
#with_context
test_something(self):
# Do something
Depending on how you test you may be able to use the test client. Example:
SomeTestCase(unittest2.TestCase):
setUp(self):
self.app = Flask(__name__)
self.client = self.app.text_client()
test_something(self):
response = self.client.get('/something')
# check response
I'm fairly new to Python, so my apologies in advance if this is much ado for something basic.
I have situation similar to How do you set up a Flask application with SQLAlchemy for testing? The big difference for me is that unlike most other Flask examples I see on the Internet, most of the code I have for my application is in a class. For some reason, this is causing my unit testing to not work correctly. Below is a basic setup of my application and tests:
Application:
from Flask import Flask
app = Flask(__name__)
class MyApplication():
def __init__(self, param1, param2):
app.add_url("/path/<methodParam>", "method1", self.method1, methods=["POST"])
# Initialize the app
def getApplication(self):
options = # application configuration options
middleware = ApplicationMiddleware(app, options)
return middleware
def method1(self, methodParam):
# Does useful stuff that should be tested
# More methods, etc.
Application Tests:
import unittest
from apppackage import MyApplication
class ApplicationTestCase(unittest.TestCase):
def setUp(self):
self.tearDown()
param1 = # Param values
param2 = # Param values
# Other local setup
self.app = MyApplication(param1, param2).app.test_client()
def tearDown(self):
# Clean up tests
def test_method1(self):
methodParam = # Param value
response = self.app.post("path/methodParam")
assert(reponse.status_code == 200)
When I run my tests via
nosetests --with-coverage --cover-package apppackage
./test/test_application.py
I get the following error:
param2).app.test_client() AttributeError: MyApplication instance has
no attribute 'app'
I've tried moving app inside the class declaration, but that doesn't do any good, and isn't how every other unit testing guide I've seen does it. Why can't my unit tests find the "app" attribute?
Your unit test cannot find the "app" attribute because MyApplication does not have one. There is an "app" attribute in the module where MyApplication is defined. But those are two separate places.
Perhaps try the following:
class MyApplication(object):
def __init__(self, param1, param2):
self.app = Flask(__name__)
self.app.add_url("/path/<methodParam>", "method1", self.method1, methods=["POST"])
# Initialize the app
Alternatively, you also seem to have a "getApplication" method which you aren't really doing anything with, but I imagine that you're using it for something. Perhaps you actually want this in your test...
def setUp(self):
self.tearDown()
param1 = # Param values
param2 = # Param values
# Other local setup
self.app = MyApplication(param1, param2).getApplication().test_client()