Infer from context sensitive return expressions #60909
Open
+2,881
−10
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
typescript-bot
added
the
For Uncommitted Bug
Andarist
commented
Jan 3, 2025
| inferFromAnnotatedParameters(signature, contextualSignature, inferenceContext!); | ||
| } | ||
| } | ||
| if (contextualSignature && !getReturnTypeFromAnnotation(node) && !signature.resolvedReturnType) { | ||
| const returnType = getReturnTypeFromBody(node, checkMode); | ||
| let contextualReturnType: Type; |
There was a problem hiding this comment.
I literally wrote this code in August so I need to take another look at this, self-review it and add more tests. In the meantime though, it could be helpful for me to learn what the extended test suite thinks about this. cc @jakebailey :p
There was a problem hiding this comment.
Hm, damn self-check :p I need to fix this first: repro
|
@typescript-bot test it |
|
Hey @jakebailey, the results of running the DT tests are ready. Everything looks the same! |
|
@jakebailey Here are the results of running the user tests with tsc comparing Everything looks good! |
|
@jakebailey Here they are:
tscComparison Report - baseline..pr
System info unknown
Hosts
Scenarios
Developer Information: |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
@jakebailey Here are the results of running the top 400 repos with tsc comparing Everything looks good! |
|
Ok, I think this one is in good shape for review. I've only made a small change to the code - I don't think it will impact any code in the wild but it might be good to rerun the extended tests. |
Andarist
commented
Jan 6, 2025
| @@ -1329,11 +1329,14 @@ export const enum CheckMode { | |||
| Inferential = 1 << 1, // Inferential typing | |||
| SkipContextSensitive = 1 << 2, // Skip context sensitive function expressions | |||
| SkipGenericFunctions = 1 << 3, // Skip single signature generic functions | |||
| IsForSignatureHelp = 1 << 4, // Call resolution for purposes of signature help | |||
| RestBindingElement = 1 << 5, // Checking a type that is going to be used to determine the type of a rest binding element | |||
| SkipReturnTypeFromBodyInference = 1 << 4, // Skip inferring from return types of context sensitive functions | |||
There was a problem hiding this comment.
It's separate from SkipGenericFunctions because getReturnTypeFromBody removes SkipGenericFunctions bit - so when the compiler gets to a function node with type parameters within a context-sensitive function's return it can't just use SkipGenericFunctions to skip over inferring its own return type from body.
The goal of SkipReturnTypeFromBodyInference is to persist through getReturnTypeFromBody.
Andarist
commented
Jan 6, 2025
| const inferenceContext = getInferenceContext(node); | ||
| const isReturnContextSensitive = !!node.body && (node.body.kind === SyntaxKind.Block ? forEachReturnStatement(node.body as Block, statement => !!statement.expression && isContextSensitive(statement.expression)) : isContextSensitive(node.body)); | ||
| returnType = getReturnTypeFromBody(node, checkMode | (isReturnContextSensitive ? CheckMode.SkipContextSensitive : 0)); | ||
| inferTypes(inferenceContext!.inferences, returnType, contextualReturnType); |
There was a problem hiding this comment.
alternatively, this could be handled by intra expression inference but that is order-sensitive and traditionally simple cases like this one aren't:
declare function test<T>(_: {
stuff: T,
consume: (arg: T) => void
}): void
test({
consume: (arg) => {},
stuff: 'foo' // this can come after `consume`
})So the reason I put this logic here is that it allows for the same order-independence
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.
fixes #60720
fixes #57021