sindresorhus/type-fest

`NonEmptyObject` fails for objects with dynamic properties

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#821 opened on Feb 27, 2024

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 (3 comments) (1 reaction) (0 assignees)TypeScript (471 forks)batch import
buggood first issuehelp wanted

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Description

The following code is considered as valid by Typescript, although I was expecting it to complain that the filter foo in commonArguments was empty.

import type { NonEmptyObject } from "type-fest"

interface CommonArguments {
  [filter: string]: NonEmptyObject<{ [argument: string]: string | number | undefined }>
}

export const commonArguments: CommonArguments = {
  foo: {}
}

Contributor guide

Research direction
Examine the implementation of NonEmptyObject in the source code and understand how it handles index signatures to determine why objects with dynamic properties like { [key: string]: ... } are incorrectly considered non empty even when empty.
Tech stack
typescript
Domain
developer 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.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
TypeScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65