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Rslint

    no-callback-literal

    Unreleased

    Configuration

    rslint.config.ts
    import { defineConfig } from '@rslint/core';

export default defineConfig([
  {
    plugins: ['node'],
    rules: {
      'node/no-callback-literal': 'error',
    },
  },
]);

    Rule Details

    Enforce the Node.js convention of passing an error as the first callback argument. Calls to identifiers named cb or callback report literal values other than null, including strings, numbers, booleans, regular expressions, arrays, objects, and template literals.

    Examples of incorrect code for this rule:

    cb('Request failed');
cb({ message: 'Request failed' });
callback(0);

    Examples of correct code for this rule:

    cb(undefined);
cb(null, result);
callback(new Error('Request failed'));
callback(error);

    The rule checks syntax and allows expressions whose value may be an error. It does not verify variable types. Calls without arguments and member calls such as object.callback('message') are allowed.

    This rule has no options.

    Differences from upstream

    rslint reports regular expression literals in the first callback argument, including newer syntax such as cb(/(?i:error)/). When ESLint runs on a Node.js version that does not support that syntax, such as Node.js 22.18.0, the upstream rule may allow the same code. Use an Error for failures or put the regular expression in the result position, for example cb(null, /(?i:error)/).

    Original Documentation