eslint/no-underscore-dangle Suspicious
What it does
Disallows dangling underscores in identifiers.
Why is this bad?
There is a long history of using _ as a prefix or suffix for private members in JavaScript. It is however recommended to use the formal private class feature introduced in ES2022. See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/Private_elements for more information.
Examples
Examples of incorrect code for this rule:
let foo_;
const __proto__ = {};
foo._bar();Examples of correct code for this rule:
const _ = require("underscore");
const obj = _.contains(items, item);
obj.__proto__ = {};
const file = __filename;
function foo(_bar) {}
const bar = { onClick(_bar) {} };
const baz = (_bar) => {};Configuration
allow
type: string[]
default: []
An array of variable names that are allowed to have dangling underscores.
allowAfterSuper
type: boolean
default: false
Whether to allow dangling underscores in members of the super object.
allowAfterThis
type: boolean
default: false
Whether to allow dangling underscores in members of the this object.
allowAfterThisConstructor
type: boolean
default: false
Whether to allow dangling underscores in members of the this.constructor object.
allowFunctionParams
type: boolean
default: true
Whether to allow dangling underscores in function parameter names.
allowInArrayDestructuring
type: boolean
default: true
Whether to allow dangling underscores in variable names assigned by array destructuring.
allowInObjectDestructuring
type: boolean
default: true
Whether to allow dangling underscores in variable names assigned by object destructuring.
enforceInClassFields
type: boolean
default: false
Whether to enforce dangling underscores in class field names.
enforceInMethodNames
type: boolean
default: false
Whether to enforce dangling underscores in method names.
How to use
To enable this rule using the config file or in the CLI, you can use:
{
"rules": {
"no-underscore-dangle": "error"
}
}import { defineConfig } from "oxlint";
export default defineConfig({
rules: {
"no-underscore-dangle": "error",
},
});oxlint --deny no-underscore-dangleVersion
This rule was added in v1.62.0.