Fix capture function to preserve type identity
#4
Conversation
This file contains 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
The `capture` function should pass-through any type it is given, in fact, it should act as an identity-function from the type perspective.
It should act as an identity function from type perspective. The use-case is that CancellablePromise might be enhanced with some additional information, such as progress reporting. We need the enhancements to be preserved when the promise is passed through the `capture` function. Before the fix, the return type from `capture` would be a bare CancellablePromise<T>, hiding any additional features of the particular type that inherited from CancellablePromise<T>.
ondrej-stanek-ozobot
force-pushed
the
fix-capture-function-to-preserve-type-identity
branch
from
6c52548
to
36558d4
Compare
srmagura
requested changes
Jan 19, 2023
There was a problem hiding this comment.
Hey @ondrej-stanek-ozobot, thanks for this change! It looks good.
Can you fix the Prettier and ESLint issues in the code you added to utils.test.ts? Once that is resolved, I will merge and deploy a new version.
The nested block was there for documentation purposes.
|
Sure, no problem, please review the fixes. |
|
Just published 1.1.2 to npm. Thanks for your contribution :) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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
capturefunction used inbuildCancellablePromisehelper function hides the type that is passed to it.The
capturefunction should act as an identity function from type perspective.The use-case is that
CancellablePromise<T>might be subclassed or enhanced with some additional information, such as progress reporting. We need the enhancements to be preserved when the an enhanced CancellablePromise is passed through thecapturefunction.Before the fix, the return type from
capturewould be a bareCancellablePromise<T>, hiding any additional features of the particular type that inherited fromCancellablePromise<T>and was passed tocapture.This issue is shown in the automted compile-time test that is part of this PR. The step
$ yarn tscfails when the test is run on the original codebase, but passes after the proposed fix.Thanks for your work on the
real-cancellable-promisepackage! I am happy I finally found a solid solution to the promise cancellation problem.