Microsoft/TypeScript

Intl.Collator#compare method type does not match spec

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#62,048 opened on Jul 11, 2025

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 (4 comments) (0 reactions) (0 assignees)TypeScript (48,455 stars) (6,726 forks)batch import
BugDomain: lib.d.tsHelp Wanted

Description

⚙ Compilation target

ES2022

⚙ Library

N/A

Missing / Incorrect Definition

The Intl.Collator object has a compare method which is declared as compare(x: string, y: string): number; but according to the relevant spec is actually get compare(): (this: void, x: string, y: string) => number. Importantly, the spec states that

The returned function is bound to collator so that it can be passed directly to Array.prototype.sort or other functions

Sample Code

I'm having trouble putting together a Playground example that cares about the difference (which is admittedly subtle!) but it's the cause of https://github.com/typescript-eslint/typescript-eslint/issues/7098

Documentation Link

Collator#compare spec MDN docs on compare method

Contributor guide

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
TypeScriptIntl API
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
Examine the TypeScript standard library definition for Intl.Collator in lib.es2022.intl.d.ts (or similar). The compare property is currently defined as a method but should be a getter that returns a function. Verify the exact signature per ECMA 402 spec and update the type accordingly. Reference the linked spec and the related typescript eslint issue for context.