Description

function* sample() {
    const a = yield 1 // error, as expected, a is implicitly any
    const { b } = yield 1 // no error, but expected, b is implicitly any
    const [c] = yield 1 // no error, but expected, c is implicitly any
}

Contributor guide

Tech stack

typescript

Domain

backenddeveloper experience

Issue type

bug

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

3

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

half day

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

stale

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

TypeScriptgeneratorsdestructuringimplicit any types

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

20

Research direction

The issue is that implicit any errors are not reported when destructuring the result of a yield expression in a generator. The fix likely involves extending the existing logic that reports implicit any for a bare yield (as implemented in issue #41348). Look at the type checker (src/compiler/checker.ts) to find where yield expressions are checked and ensure destructuring patterns are also considered. Examine the check for 'yield' result type and propagate the implicit any error through destructuring. Also, add or modify test cases in tests/cases/compiler/ to cover this scenario. The related issue and linked PR for #41348 can provide guidance on the expected changes.