Python unittest with test/ and src/ not finding src modules

Question

I have a simple directory structure:

proj/
    src/
        __init__.py
        foo.py
        bar.py
    test/
        __init__.py
        test_foo.py

test_foo.py

import unittest

import sys
sys.path.append('../src')

from src import foo

class TestFoo(unittest.TestCase):

  def test_foo(self):
    foo.start()


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

foo.py

import bar

def start():
  bar.do_stuff()

When running my test (I'm using vscode), I get the following error:

Failed to import test module: test_foo
Traceback (most recent call last):
  File "~/.pyenv/versions/3.8.6/lib/python3.8/unittest/loader.py", line 436, in _find_test_path
    module = self._get_module_from_name(name)
  File "~/.pyenv/versions/3.8.6/lib/python3.8/unittest/loader.py", line 377, in _get_module_from_name
    __import__(name)
  File "~/proj/test/test_foo.py", line 6, in <module>
    from src import foo
  File "~/proj/src/foo.py", line 1, in <module>
    import bar
ModuleNotFoundError: No module named 'bar'

I'm not sure why the test can't discover the src/bar when importing src/foo

Answer 1

What is in your bar.py file? Just the do_stuff() function? Or is the do_stuff() function a method of object bar?

Depending on the answer to the question above, try doing something like this in your foo.py file:

from proj.src.bar import [name of function you're testing here]

In your specific case, it would be like this if do_stuff() is a standalone function:

from proj.src.bar import do_stuff

and then your foo.py file would be:

from proj.src.bar import do_stuff

def stuff():
  do_stuff()

However, if do_stuff() is a method of the bar object, it would probably be something like this, although it's hard to tell without knowing the contents of the bar.py file:

from proj.src.bar import bar

and then your foo.py file would be similar to the way you have it now:

from proj.src.bar import bar

def stuff():
  bar.do_stuff()

I recently ran into a similar problem when trying to import one neighboring file into another. This link helped me out, too.