x is None or y is None VS not all((x, y))

[virajkanwade]

Bug Report

(A clear and concise description of what the bug is.)

utils/emailsender.py:22: error: Argument "MAIL_USERNAME" to "ConnectionConfig" has incompatible type "str | None"; expected "str" [arg-type]

To Reproduce

# Ideally, a small sample program that demonstrates the problem.
# Or even better, a reproducible playground link https://mypy-play.net/ (use the "Gist" button)

if not all((
    self.settings.MAIL_USERNAME,
    self.settings.MAIL_PASSWORD,
    self.settings.EMAIL_SUPPORT,
    self.settings.MAIL_SERVER
)):
    raise ValueError("Mail settings must be configured and cannot be None.")

conf = ConnectionConfig(
            MAIL_USERNAME=self.settings.EMAIL_USERNAME,
            MAIL_PASSWORD=self.settings.EMAIL_PASSWORD,
            MAIL_PORT=self.settings.EMAIL_PORT,
            MAIL_FROM=self.settings.EMAIL_SUPPORT_ADDRESS,
            MAIL_SERVER=self.settings.EMAIL_SERVER,
            MAIL_SSL_TLS=self.settings.EMAIL_SSL_TLS,
            MAIL_STARTTLS=self.settings.EMAIL_STARTTLS,
        )

This raises the warning during check utils/emailsender.py:22: error: Argument "MAIL_USERNAME" to "ConnectionConfig" has incompatible type "str | None"; expected "str" [arg-type]

If i change it to

if (self.settings.EMAIL_USERNAME is None
            or self.settings.EMAIL_PASSWORD is None
            or self.settings.EMAIL_SUPPORT_ADDRESS is None
            or self.settings.EMAIL_SERVER is None
        ):
            raise ValueError("Mail settings must be configured and cannot be None.")

it reports no issues

Expected Behavior

In both cases it should not raise the warning.

Actual Behavior

Your Environment

• Mypy version used:
• Mypy command-line flags:
• Mypy configuration options from mypy.ini (and other config files):
• Python version used:

[erictraut]

I think this is a duplicate of #17149.

[virajkanwade]

I tried searching but for some reason didn't see it. Thanks for pointing it out.