Fix fold return type annotations - #82
Merged
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The foldLeft and foldRight annotations used a single template for the initial value and the callback result, which rejects valid heterogeneous folds, as @axlon pointed out in #77. That fix went too far the other way, though, since None returns the initial value at runtime, so the true return type is the union of the two. This types the base methods as returning S|R and adds exact overriding docblocks on Some and None, which removes the false positives without blessing any code that could fail at runtime, and leaves our own PHPStan run clean with no baseline changes.