Support for non-PIPE outputs

[abjonnes]

I have some code with uses subprocess with a file handle as the stdout argument. The subprocess module will write the output of the command to the file handle, and my code does not directly call communicate. When I register a command with fake_process in the tests with some stdout content specified, the file doesn't seem to have the expected content written to it. Have I overlooked something, or is that not supported by this library?

Example:

# tests/test_sp.py
import subprocess


def test_sp(fake_process):
    fake_process.register_subprocess(["echo", "hello"], stdout="hello\n")

    filename = "file.txt"
    with open(filename, "w") as handle:
        subprocess.run(["echo", "hello"], stdout=handle)

    assert open(filename).read() == "hello\n"

Result:

╰─❯ poetry run pytest
============================= test session starts ==============================
platform darwin -- Python 3.9.7, pytest-5.4.3, py-1.10.0, pluggy-0.13.1
rootdir: [...]/fake_sp_test
plugins: subprocess-1.3.0
collected 1 item                                                               

tests/test_sp.py F                                                       [100%]

=================================== FAILURES ===================================
___________________________________ test_sp ____________________________________

fake_process = <pytest_subprocess.core.FakeProcess object at 0x10ee90190>

    def test_sp(fake_process):
        fake_process.register_subprocess(["echo", "hello"], stdout="hello\n")
    
        filename = "file.txt"
        with open(filename, "w") as handle:
            subprocess.run(["echo", "hello"], stdout=handle)
    
>       assert open(filename).read() == "hello\n"
E       AssertionError: assert '' == 'hello\n'
E         - hello

tests/test_sp.py:11: AssertionError
=========================== short test summary info ============================
FAILED tests/test_sp.py::test_sp - AssertionError: assert '' == 'hello\n'
============================== 1 failed in 0.06s ===============================

[aklajnert]

I've missed that use case, it's not supported right now. I think it could be done currently by using the callback function, but it would be quite clunky.
I'll fix the code to support this feature soon. Thanks for reporting.

[abjonnes]

Awesome, thanks!

[aklajnert]

This fix has been just released in 1.3.1.