Add support for with snapshot()

[zmievsa]

When you develop libraries, you often need to check that your library raises some exception at runtime.

I created better-devtools (Samuel Colvin's devtools fork) to automate this process and I would like to propose a similar tool for snapshot.

It would allow for something like the following syntax:

with snapshot():
    raise ValueError

Which would translate into something like the following:

with snapshot(pytest.raises(ValueError)):
    raise ValueError

[15r10nk]

I use something like this in my own tests.

def test_with():
    with raises(snapshot("ZeroDivisionError: division by zero")):
        print(1/0)

the implementation looks like this:

@contextlib.contextmanager
def raises(snapshot):
    with pytest.raises(Exception) as excinfo:
        yield

    assert f"{type(excinfo.value).__name__}: {excinfo.value}" == snapshot

would this fit your needs? I could put such generic utils in a inline_snapshot.extras module.

[zmievsa]

Yup, it would! Looks great! You really did think of all use cases.

This is an amazing project.

[alexmojaki]

That is very cool. I think I've had times where I would have used this, and it didn't occur to me that vanilla snapshot could do the trick.