sindresorhus/eslint-plugin-unicorn

Rule proposal: `arguments-length`

Closed

#1,998 opened on Nov 28, 2022

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 (5 comments) (4 reactions) (0 assignees)JavaScript (468 forks)user submission
help wantednew rule

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Description

Description

A common source of bugs during refactoring is when functions are called with less or more arguments than they expect. Prior art includes sonarjs/no-extra-arguments, but I would like to see a more strict version that also triggers on too few arguments.

Fail

const fn = (a, b) => a + b;
fn(1); // Expected 2 function arguments, but got 1

const fn = (a, b) => a + b;
fn(1, 2, 3); // Expected 2 function arguments, but got 3

Pass

const fn = (a, b) => a + b;
fn(1, 2);

Additional Info

Unlike sonarjs/no-extra-arguments, I'd not make a exception for arguments because such usage should be replaced with spread syntax.

Contributor guide

Research direction
Review the sonarjs/no extra arguments rule for reference, then study ESLint's custom rule creation guide and the existing patterns in eslint plugin unicorn. The rule should flag calls with too few or too many arguments, excluding rest parameters. Check issue comments for any additional requirements.
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.
1-2 days
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
ESLint rule APIJavaScript AST basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70