sindresorhus/eslint-plugin-unicorn

Rule proposal: `no-duplicate-loops`

Open

#846 opened on Sep 30, 2020

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 (24 comments) (7 reactions) (0 assignees)JavaScript (5,022 stars) (468 forks)user submission
help wantednew rule

Description

I've seen this a couple of times

Error

for (const gamma of bars.map(alpha => alpha.beta.gamma)) {
  gamma('ray')
}
 
for (const act of actions.filter(act => typeof act === 'function')) {
  act('a fool')
}

Pass

for (const alpha of bars) {
  alpha.beta.gamma('ray')
}


for (const act of actions) {
  if (typeof act === 'function') {
    act('a fool')
  }
}

Contributor guide

Tech stack
javascriptnodejs
Domain
toolingdeveloper experience
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.
half day
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.
mostly clear
Prerequisites
ESLint plugin developmentAST knowledgeJavaScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50
Research direction
Review existing rules in eslint plugin unicorn to understand the pattern for rule creation. Study the AST structure of the 'no duplicate loops' pattern by analyzing the provided examples. Check the issue comments for any proposed implementation details or maintainer preferences. Familiarize yourself with ESLint's rule API and testing utilities.