coverage subprocess

.coveragerc

[run]
branch = True
source = .

impl.py

def foo():
    return "foo"


def bar():
    return "bar"

requirements.txt

coverage
pytest

sitecustomize.py

import coverage
coverage.process_startup()

subproc_test.py

from impl import foo, bar


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


def test_bar():
    assert bar() == "bar"

test.py

import subprocess

import os
os.environ['COVERAGE_PROCESS_START'] = ".coveragerc"


def test_via_subproc():
    proc = subprocess.Popen(["py.test", "subproc_test.py", "-v"])
    proc.wait()