Rule proposal: `no-negated-some-every`

Repository metrics

Stars

5,022 stars (5,022 stars)

PR merge metrics

Avg merge 1d 16h (Avg merge 1d 16h)399 merged PRs in 30d (399 merged PRs in 30d)

Description

[
    ![].every(() => true) === [].some(() => !true),
    ![0].every(() => true) === [0].some(() => !true),
    ![1].every(() => true) === [1].some(() => !true),
    ![].every(() => false) === [].some(() => !false),
    ![0].every(() => false) === [0].some(() => !false),
    ![1].every(() => false) === [1].some(() => !false),
]

if (!array.some(element => test(element)));

if (!array.every(element => test(element)));

if (array.every(element => !test(element)));

if (array.some(element => !test(element)));

if (!array.every(Boolean));

if (
	  !array.some(element => {
	  	if (foo) {
			return true;
		}

	  	if (bar) {
			return false;
		}

		return baz;
	  })
);

Contributor guide

Research direction

Implement a new ESLint rule that suggests replacing `!array.every()` with `array.some()` and vice versa. Start by identifying negated `every` and `some` calls in AST, then provide auto fix to flip the call and negate the predicate. Consider edge cases like complex predicate bodies or callbacks that are not simple arrow functions.

Tech stack

javascript

Domain

tooling

Issue type

Feature

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

2

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.

Fresh

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

Clear

Prerequisites

JavaScriptESLint

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

70