Flask EZ Test

Making flask app's that serve html and use a flasksqlalchemy backend engine easier to test

Setup

Make sure you set the environemnt variable FLASK_APP to the file path of your main app module

flaskeztest will expect there to be a variable named 'app' under this module and another named 'db'. 'app' should be a Flask object and 'db' should be an SQLAlchemy object.

# myapp/app.py
from model import db
app = Flask(__name__)
db.init_app(app)
...

# myapp/model.py
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()
...

Then run all test suites with eztest command

Other options

for running one testcase under a suite

$ eztest [suite] [testcase]

or

for running one whole suite

$ eztest [suite]

where suite is the same as a suite module without .py and testcase is the same as the classname of the testcase

In General, the eztest object get's its settings from a special test config module which is set in app.config as EZTEST_CONFIG_MODULE

i.e:

# test/config.py

EZTEST_FIXTURES_DIR = 'test/fixtures'
EZTEST_SUITES_PACKAGE = 'test/suites'

Make sure that the suites package has a `suite_names` list in its __init__.py'

And then in normal config module

Then in flask app module set config from normal config module

Developing Testcases

Test cases are pacakged in modules that expose a 'suite' object in its global scope

Example suite 'index':

# test/suites/index.py
from flaskeztest import EZTestSuite, EZTestCase

class SimpleTestCase(EZTestCase):

    FIXTURE = 'myfixture'  # json filename without .json

    def runTest(self):
        self.assertTrue(...the truth...)

...

suite = EZTestSuite('index', __name__)

Using Fixtures

Fixtures are a json file representing data to insert into the database before a test case runs

Example:

myfix.json

[
    {
        "model": "User",
        "row": {
            "name": "Bob",
            "email: "[email protected]"
        }
    }
]

or with multiple entries for one model:

myfix2.json

[
    {
        "model": "User",
        "rows": [
            {
                "name": "Bob",
                "email: "[email protected]"
            },
            {
                "name": "Alice",
                "email: "[email protected]"
            }
        ]
    }
]

The EZTestCase class

EZTestCase's setUp method loads the fixture named in its FIXTURE class variable which places the data for each field into the expected_models dict.

For instance:

class TC(EZTestCase):

    FIXTURE = 'myfix'  # Referring to the first fixture above

    def runTest(self):

        # Passes
        self.assertEqual(self.expected_models['User']['name'], 'Bob')

class TC2(EZTestCase):

    FIXTURE = 'myfix2' # Referring to the second fixture above

    def runTest(self):

        # Passes as well, but would give index error on first test case
        self.assertEqual(self.expected_models['User'][1]['name], 'Alice')

Two other useful method of the EZTestCase class is 'get_endpoint' and 'does_field_exist'.

Example:

class TC(EZTestCase):
    FIXTURE = 'myfix2'
    def runTest(self):
        # Pull up user details for Alice
        self.get_endpoint('index.users', user_id=2)  # Assume that index.users take user primary key as argument

        # Assert we see second user on page
        self.assertTrue(self.does_field_exist('User', 'name', 1))

In general most of the methods defined for EZTestCase are useful to include in your own test case classes. Check out flaskeztest/eztestcase.py for more of them.

Using capybara

Flaskeztest allows for querying the html returned from pages using capybara. Check out the docs at https://elliterate.github.io/capybara.py/ for all the useful methods that can be applied to the the EZTestCase.page object.

Running with a reflected SQL database

Sometimes flaskeztest may be used with a flask app that is not using declarative models with sqlalchemy, but instead want to simply use a database whose schema is contained within the remote database itself.

One can specify the remote database that flask-eztest should reflect by setting the EZTEST_REFLECTED_DB_URI in the test config module

i.e

# test/config.py
...
EZTEST_REFLECTED_DB_URI = 'mysql://..."