Python Testing with pytest

Running Coverage on a Single File

A lot of lovely single-file Python applications could use a little test coverage. Single-file applications, sometimes called scripts, are often not packaged or deployed, but just shared as single files. In those cases, it’s handy to put the test code right into the script.

Here’s a small example:

ch9/single_file.py

def foo():
    return "foo"


def bar():
    return "bar"


def baz():
    return "baz"


def main():
    print(foo(), baz())


if __name__ == "__main__":  # pragma: no cover
    main()

# test code, requires pytest


def test_foo():
    assert foo() == "foo"


def test_baz():
    assert baz() == "baz"


def test_main(capsys):
 main() ...