sindresorhus/eslint-plugin-unicorn

Rule proposal: `prefer-operator-assignment`

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#1,805 opened on May 2, 2022

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help wantednew rule

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Description

Description

if the new string starts with the previous string, prefer operator assignment as less code is written

Fail

foo = foo + 'baz qux'

foo = `${foo} baz ${qux}`

Pass

foo += 'baz qux'

foo += ` baz ${qux}`

Additional Info

ESLint's operator-assignment doesn't catch case with template literal interpolation https://eslint.org/demo#eyJ0ZXh0IjoibGV0IGZvbyA9IGAke2Zvb30gYmF6ICR7cXV4fWBcbmZvbyA9IGZvbyArICdiYXogcXV4JyIsIm9wdGlvbnMiOnsicGFyc2VyT3B0aW9ucyI6eyJlY21hVmVyc2lvbiI6ImxhdGVzdCIsInNvdXJjZVR5cGUiOiJzY3JpcHQiLCJlY21hRmVhdHVyZXMiOnt9fSwicnVsZXMiOnsiY2FwaXRhbGl6ZWQtY29tbWVudHMiOjIsIm9wZXJhdG9yLWFzc2lnbm1lbnQiOjJ9LCJlbnYiOnt9fX0=

Contributor guide

Research direction
Look at the AST for assignment expressions and template literals, then write a rule that checks if the left side of an assignment is the same variable as the right side's first part, and suggest operator assignment. Reference existing ESLint rule 'operator assignment' for implementation patterns.
Tech stack
javascript
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.
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.
Active
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