sindresorhus/eslint-plugin-unicorn

Rule proposal: `no-return-prototype-method`

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#1,098 opened on Feb 11, 2021

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help wantednew rule

Description

It's easy to forget actually calling a prototype method which leads to possibly hard-to-debug errors.

Since e.g. many array methods accept a callback or only an optional parameter, this could be handled with an allowlist per global object, e.g. Array.prototype.map wouldnt need to be checked for.

Fail

function foo(myString) {
  return string.slice(3).toLowerCase
}

function foo(myArr) {
  return myArr.map(val => val ** 2).reverse
}

Pass

function foo(myString) {
  return string.slice(3).toLowerCase()
}

function foo(myArr) {
  return myArr.map(val => val ** 2).reverse()
}

Contributor guide

Tech stack
javascriptnodejs
Domain
developer experiencetooling
Issue type
feature
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.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaScript knowledgeESLint rule development basicsAST fundamentals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
Study existing rules in eslint plugin unicorn that check for method references, such as `no array callback reference`. The issue suggests an allowlist per global object; consider implementing a configuration option. Review the ESLint guide for custom rules. The issue comments may provide additional insights or constraints.