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eslint/prefer-arrow-callback Style

🛠️ An auto-fix is available for this rule.

What it does

Requires using arrow functions for callbacks.

Why is this bad?

Arrow functions are generally better suited for callbacks because they:

• inherit this from the surrounding scope, avoiding a common source of bugs;
• are shorter and easier to read;
• cannot be used as constructors, which is desirable for callbacks.

Options

{
  "prefer-arrow-callback": [
    "error",
    {
      "allowNamedFunctions": false,
      "allowUnboundThis": true
    }
  ]
}

• allowNamedFunctions (default false) — when true, named function expressions are allowed.
• allowUnboundThis (default true) — when false, function expressions that reference this are reported even when they are not bound to a this value.

Examples

Examples of incorrect code for this rule:

foo(function (a) {
  return a;
});
foo(
  function () {
    return this.a;
  }.bind(this),
);

Examples of correct code for this rule:

foo((a) => a);
foo(function* () {
  yield;
});
foo(function () {
  this;
});
foo(function bar() {
  bar();
});

Configuration

allowNamedFunctions

type: boolean

default: false

allowUnboundThis

type: boolean

default: true

How to use

To enable this rule using the config file or in the CLI, you can use:

Config (.oxlintrc.json)

{
  "rules": {
    "prefer-arrow-callback": "error"
  }
}

Config (oxlint.config.ts)

import { defineConfig } from "oxlint";

export default defineConfig({
  rules: {
    "prefer-arrow-callback": "error",
  },
});

CLI

oxlint --deny prefer-arrow-callback

Version

This rule was added in vnext.

References

• Rule Source
• Open rule in Oxc Playground