Re: [PATCH v9 08/14] iotests: touch up log function signature

[Kevin Wolf]

Am 25.03.2020 um 00:20 hat John Snow geschrieben:
> Representing nested, recursive data structures in mypy is notoriously
> difficult; the best we can reliably do right now is denote the atom
> types as "Any" while describing the general shape of the data.
> 
> Regardless, this fully annotates the log() function.
> 
> Typing notes:
> 
> TypeVar is a Type variable that can optionally be constrained by a
> sequence of possible types. This variable is bound per-invocation such
> that the signature for filter=() requires that its callables take e.g. a
> str and return a str.
> 
> Signed-off-by: John Snow <address@hidden>

I like it. Does your version of mypy accept this? I actually get a
warning that doesn't make sense to me:

    iotests.py:392: error: Argument 1 to "info" of "Logger" has incompatible 
type "Dict[str, Any]"; expected "str"

The code looks like this:

    if isinstance(msg, (dict, list)):
        # Don't sort if it's already sorted
        do_sort = not isinstance(msg, OrderedDict)
        test_logger.info(json.dumps(msg, sort_keys=do_sort, indent=indent))
    else:
        test_logger.info(msg)

I have no idea why it would think it can still be Dict[str, Any] in the
else branch. Even after adding an 'assert not instanceof(msg, dict), it
still thinks so.

Probably time to update for me...

Kevin