SMTPD_USE_SSL only honored when set in a separate fixture

[jwodder]

On Python 3.9.2 on macOS 11.2.1, using pytest 6.2.2 and smtpdfix 0.2.9, the following fails on the client = smtplib.SMTP_SSL(...) line with an SSL error:

from email.message import EmailMessage
import smtplib

def test_smtpd_ssl(monkeypatch, smtpd):
    monkeypatch.setenv("SMTPD_USE_SSL", "True")
    client = smtplib.SMTP_SSL(smtpd.hostname, smtpd.port)
    msg = EmailMessage()
    msg["Subject"] = "Hello, World!"
    msg["To"] = "world@earth.space"
    msg["From"] = "me@here.qq"
    msg.set_content("Hi, world!  How you doin'?\n")
    client.send_message(msg)
    client.quit()
    assert len(smtpd.messages) == 1

Meanwhile, setting SMTPD_USE_SSL outside of the test in a fixture succeeds:

from email.message import EmailMessage
import smtplib
import pytest

@pytest.fixture
def mock_smtpd_use_ssl(monkeypatch):
    monkeypatch.setenv("SMTPD_USE_SSL", "True")

def test_smtpd_ssl(mock_smtpd_use_ssl, smtpd):
    client = smtplib.SMTP_SSL(smtpd.hostname, smtpd.port)
    msg = EmailMessage()
    msg["Subject"] = "Hello, World!"
    msg["To"] = "world@earth.space"
    msg["From"] = "me@here.qq"
    msg.set_content("Hi, world!  How you doin'?\n")
    client.send_message(msg)
    client.quit()
    assert len(smtpd.messages) == 1

This is presumably not the intended way to set SMTPD_USE_SSL, and so I am reporting it as a bug.

[bebleo]

Thanks @jwodder for taking the time to report this issue! 🎉

As of version 0.3.0 this behaviour can now be handled by setting the smtpd.config.use_ssl property to True.

def test_smtpd_ssl(smtpd):
    smtpd.confg.use_ssl = True  # Not using monkeypatch!
    client = smtplib.SMTP_SSL(smtpd.hostname, smtpd.port)
    msg = EmailMessage()
    msg["Subject"] = "Hello, World!"
    msg["To"] = "world@earth.space"
    msg["From"] = "me@here.qq"
    msg.set_content("Hi, world!  How you doin'?\n")
    client.send_message(msg)
    client.quit()
    assert len(smtpd.messages) == 1