CODEWITHSUNDEEP
pythonpython-unittest
Biplov Dahal
Biplov Dahal

Reputation: 41

run python file with arguments in the unit test

I have a test case where I'd like to be able to run a python file with arguments.

I have 2 files. app.py

def process_data(arg1,arg2,arg3):
        return {'msg':'ok'}


if __name__ == "__main__":
      arg1 = sys.argv[1]
      arg2 = sys.argv[2]
      arg3 = sys.argv[3]
      process_data(arg1,arg2,arg3)

test_cases.py

class TestCase(unittest.TestCase):

  def test_case1(self):

    expected_output = {'msg':'ok'}
    with os.popen("echo python app.py arg1 arg2 arg3") as o:
        output = o.read()
    output = output.strip()
    self.assertEqual(output, expected_output)





if __name__ == "__main__":
   unittest.main()

expected result is {'msg':'ok'} however the variable output returns nothing.

Upvotes: 1

Views: 948

Answers (2)

Nihal
Nihal

Reputation: 5324

There is one thing you are forgetting is process output will return as string, but you are comparing with dict, so little change in expected_output = "{'msg': 'ok'}"

import os
import unittest


class TestCase(unittest.TestCase):

    def test_case1(self):
        expected_output = "{'msg': 'ok'}"
        output = os.popen('python3 app.py arg1 arg2 arg3').read().strip()
        print('=============>', output)
        self.assertEqual(output, expected_output)


if __name__ == "__main__":
    unittest.main()

app.py

import sys


def process_data(arg1, arg2, arg3):
    print({'msg': 'ok'})
    # return pass


if __name__ == "__main__":
    arg1 = sys.argv[1]
    arg2 = sys.argv[2]
    arg3 = sys.argv[3]
    process_data(arg1, arg2, arg3)

output:

Ran 1 test in 0.025s

OK
=============> {'msg': 'ok'}

Upvotes: 2

Amit Nanaware
Amit Nanaware

Reputation: 3346

you don't need to call that function using os.popen() you can directly import that function in your test_cases.py and call it(highly recommended ) see below example:

from app import process_data

class TestCase(unittest.TestCase):

    def test_case1(self):

        expected_output = {'msg':'ok'}
        output = process_data('arg1', 'arg2', 'arg3')
        self.assertEqual(output, expected_output)


if __name__ == "__main__":
   unittest.main()

Upvotes: 2

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