Passing args as part of unittests to test pyspark script

Question

I have a python script which currently takes a command line argument 'path to the json file' and carries out some cleaning up on the data.

I am writing some unit tests where I am trying to pass path to the json file as an arg. It currently comes up with an error when no arg is passed but when it is passed i get the error:

AttributeError: 'module' object has no attribute 'data' which is data.json. 

I want to have three separate unit tests each having a different json file to be passed as an argument.

My code is as follows:

import unittest
import sys
import argparse

class TestTransform(unittest.TestCase):
    def test_transform(self,input_filename):
        target = __import__("cleaning.py")
        transform = target
        transform.ARGS(input_filename)
        self.assertTrue('Pass')

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

Answer 1

If I understood your problem correctly here is what I normally do in this case. I override the setUpClass method and make all the inputs to this class attributes that can be accessed by the tests:

class TestTransform():

    @classmethod
    def setUpClass(self, file_name):
        self.input_filename = file_name
        #Some other initialization code here

    def test_transform(self):
        target = __import__("cleaning.py")
        transform = target
        transform.ARGS(self.input_filename)
        self.assertTrue('Pass')

If you then want to make different tests with different input values you can create other classes by subclassing the TestTransform class (and of course the unittest.TestCase):

class Test1(TestTransform, unittest.TestCase):
    @classmethod
    def setUpClass(self):
        input_filename = 'MyFileName'
        #Here call the setUpClass from the TestTransform class
        TestTransform.setUpClass(input_filename)