sindresorhus/eslint-plugin-unicorn

Rule proposal: `prefer-nullish-coalescing`

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#471 opened on Dec 6, 2019

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 (5 comments) (5 reactions) (1 assignee)JavaScript (468 forks)user submission
help wantednew rule

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Description

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator

https://github.com/tc39/proposal-nullish-coalescing

let foo = (undefined || null) || bar;

// equals

let foo = (undefined || null) ?? bar;

anyway, it not safe for foo || bar -> foo ?? bar, we should use ESLint suggestion api

Contributor guide

Research direction
Explore the existing eslint plugin unicorn structure, particularly how other rules are implemented. The issue references ESLint suggestion API (issue #441), so understand that approach. Look at the nullish coalescing proposal links provided. Files to examine: likely 'rules/prefer nullish coalescing.js' (needs creation) and related test files. Check comments for any additional context or maintainer guidance.
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.
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.
Fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Mostly clear
Prerequisites
ESLint rule developmentJavaScript knowledgenullish coalescing operator
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45