Add error-code for truthy-iterable#13762
Conversation
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
cdce8p
force-pushed
the
truthy-iterable
branch
from
0f61110 to
412a3a9
Compare
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
This comment has been minimized.
|
@hauntsaninja This is related to #13686, this time for |
cdce8p
force-pushed
the
truthy-iterable
branch
from
412a3a9 to
64065e4
Compare
This comment has been minimized.
This comment has been minimized.
cdce8p
force-pushed
the
truthy-iterable
branch
from
64065e4 to
38ae87a
Compare
cdce8p
force-pushed
the
truthy-iterable
branch
from
38ae87a to
d146b47
Compare
This comment has been minimized.
This comment has been minimized.
|
Pushed a new commit to disable the error-code by default. That should minimize the impact of the PR. |
|
@JelleZijlstra Would you mind taking a look? The actual code change is quite small but I think it will be an improvement never the less. The PR is ready from my POV. |
| "Function {} could always be true in boolean context", code=codes.TRUTHY_FUNCTION | ||
| ) | ||
| ITERABLE_ALWAYS_TRUE: Final = ErrorMessage( | ||
| "{} which can always be true in boolean context. Consider using {} instead.", |
There was a problem hiding this comment.
This message reads a bit weird to me but I guess it's consistent with the other ALWAYS_TRUE messages.
There was a problem hiding this comment.
On its own, I agree. It gets better once the variables are inserted. E.g.
"var" has type "Iterable[str]" which can always be true in boolean context.
Consider using "Collection[str]" instead. [truthy-iterable]
| This is similar in concept to ensuring that an expression's type implements an expected interface (e.g. ``Sized``), | ||
| except that attempting to invoke an undefined method (e.g. ``__len__``) results in an error, | ||
| while attempting to evaluate an object in boolean context without a concrete implementation results in a truthy value. |
There was a problem hiding this comment.
I don't understand what this sentence is trying to say. What is "this" exactly?
There was a problem hiding this comment.
As best as I can tell, "this" refers to the check itself and the fact that it doesn't highlight a concrete issue but rather only a potential one.
|
According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉 |
2 participants
Add a separate error code for
truthy-iterable.Iterabledoes not implement__len__, so passing aGeneratorwould always evaluate totrue. SuggestCollectionas alternative.In most cases this isn't an issue as the function is often called with
listanyway. However, the dedicated check can pinpoint subtle errors that might get unnoticed otherwise.