为什么在 python 中进行单元测试时，我期望状态代码为 200，但状态代码为 404？

Question

I am writing a unit test case in python using unittest and pytest for a file. Out of the many functions I am unable to understand why doesn't it execute as a successfully passed test case. Here is function which displays a settings page,and upon a successfull call it displays an html page.

@app.route('/settings', methods=['GET', 'POST'])
@login_required
def settings():
    global application_inst
    if request.method == 'POST':
        print("Setting changed")

    return render_template('settings.html', user=session['user'], application=application_inst)

and the unit testcase for the function is written below as:

class MyApp(unittest.TestCase):
    def setUp(self):
        self.app = create_app(db)
        self.client = self.app.test_client(self)

        with self.app.app_context():
            # create all tables
            db.create_all()

    def tearDown(self):
        pass

    def test_settings_passed(self):
        response = self.client.get('/settings', follow_redirects=True)
        self.assertEqual(response.status_code, 200)

The error that I get in the stacktrace is:

test_app.py::MyApp::test_settings_passed FAILED                          [100%]ENV :default
############ INIT ############
############ INIT ############
############ INIT ############

 
200 != 404

Expected :404
Actual   :200
<Click to see difference>

Please help me on this.

Answer 1

Try to change so that self.client would be executed within app_context() as eg

class MyApp(unittest.TestCase):
    def setUp(self):
        self.app = create_app(db)
        self.client = self.app.test_client(self)

        with self.app.app_context():
            # create all tables
            db.create_all()

    def tearDown(self):
        pass

    def test_settings_passed(self):
        with self.app.app_context():
            response = self.client.get('/settings', follow_redirects=True)
            self.assertEqual(response.status_code, 200)

I have created the same scenario and it works with and without app_context for me. Also I have used this command to execute tests:

python -m unittest tests/test_the_test.py 

---

Also it depends of how you have set up the app. Used python3.7 for example bellow.

Mine is like this:

├── app.py
├── index
│   ├── __init__.py
│   └── routes.py
└── tests
    └── test_the_test.py

my app.py is like this:

from flask import Flask



def create_app():
    app = Flask(__name__)
    from index import bp
    app.register_blueprint(bp)
    return app

My index/__init__.py like this:

from flask import Blueprint

bp = Blueprint(__name__, '/')

from index import routes

my index/routes.py like this:

from index import bp
from flask import jsonify

@bp.route('/test')
def test():
    print('goes here?')
    return jsonify({'result': True})

my tests/test_the_test.py like this:

import unittest

from app import create_app


class MyApp(unittest.TestCase):
    def setUp(self):
        self.app = create_app()
        self.client = self.app.test_client(self)

    def tearDown(self):
        pass

    def test_settings_passed(self):
        response = self.client.get('/test', follow_redirects=True)
        self.assertEqual(response.status_code, 200)

    def test_settings_failed(self):
        response = self.client.get('/test_not_exist', follow_redirects=True)
        self.assertEqual(response.status_code, 404)

Executing this command:

python -m unittest tests/test_the_test.py 

And my setup works properly, does the testing and give a correct result for both when the endpoint exists and when it doesn't exist.

result:

python -m unittest tests/test_the_test.py 
.goes here?
.
----------------------------------------------------------------------
Ran 2 tests in 0.006s

OK