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Code is written once but read many times. Abbreviations like e, cb, err, req, and res save a few keystrokes but force every future reader to decode the shorthand. This rule flags discouraged abbreviations and suggests full-word replacements, with an auto-fix when there is exactly one possible replacement.
Recommended✅ recommended
Fixable🔧 Auto-fix (single replacement only)
Suggestions—

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Examples

const e = new Error();
const e = document.createEvent('Event');
class Btn {}

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Configuration

eslint.config.js
export default [
  {
    rules: {
      'unicorn/prevent-abbreviations': ['error', {
        replacements: {},
        extendDefaultReplacements: true,
        allowList: {},
        extendDefaultAllowList: true,
        checkDefaultAndNamespaceImports: 'internal',
        checkShorthandImports: 'internal',
        checkShorthandProperties: false,
        checkProperties: false,
        checkVariables: true,
        checkFilenames: true,
        ignore: [],
      }],
    },
  },
];

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replacements

Type: object Extend or override the default replacements. Each key is an abbreviation; the value is an object mapping replacement names to true (enabled) or false (disabled). 
'unicorn/prevent-abbreviations': ['error', {
  replacements: {
    e: { event: false },       // disable e → event, keep e → error
    res: false,                 // disable all replacements for `res`
    cmd: { command: true },     // add custom cmd → command
    errCb: { handleError: true }, // add custom errCb → handleError
  },
}]

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extendDefaultReplacements

Type: boolean — Default: true When false, the replacements option completely replaces the built-in list instead of extending it.

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allowList

Type: object Map of exact identifier names (case-sensitive) to true to exempt them from reporting. 
// Allow `getInitialProps` even though `props` is normally discouraged
{ allowList: { getInitialProps: true } }

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extendDefaultAllowList

Type: boolean — Default: true When false, the allowList option completely replaces the built-in allow list.

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checkDefaultAndNamespaceImports

Type: 'internal' | boolean — Default: 'internal'
  • 'internal' — check default and namespace import names only for internal modules (relative or absolute paths, not node_modules).
  • true — check all default and namespace import names.
  • false — skip default and namespace import names entirely.

​
checkShorthandImports

Type: 'internal' | boolean — Default: 'internal' Same as checkDefaultAndNamespaceImports but for shorthand ({named}) imports.

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checkShorthandProperties

Type: boolean — Default: false When true, destructured shorthand property names are also checked. 
// Reported when checkShorthandProperties: true
const { err } = foo;
function f({ err }) {}

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checkProperties

Type: boolean — Default: false When true, object property keys and class member names are checked.

​
checkVariables

Type: boolean — Default: true Set to false to skip variable name checks entirely.

​
checkFilenames

Type: boolean — Default: true Set to false to skip filename checks. When enabled, only the basename is tested (not the full path).

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ignore

Type: Array<string | RegExp> — Default: [] Patterns to ignore. Strings are interpreted as regular expressions. 
{ ignore: ['\\.e2e$', /^ignore/i] }
The auto-fix only applies when there is exactly one possible replacement. When multiple replacements exist, the rule reports all suggestions but leaves the rename to you.

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