eslint-plugin-no-function-declare-after-return

1.1.0 verified Sat Apr 25 auth: no javascript

An ESLint plugin that enforces a code style rule disallowing function declarations after a return statement within the same scope. Version 1.1.0 is the latest stable release, with auto-fix support added in this version. The plugin is mature, actively maintained, and has no known security issues. It differs from ESLint's built-in no-unreachable rule by focusing specifically on hoisted function declarations after return, which are syntactically valid but harm readability. The plugin is lightweight with zero runtime dependencies besides ESLint.

Common errors

error Error: Failed to load plugin 'no-function-declare-after-return': Unable to load rule 'no-function-declare-after-return/no-function-declare-after-return' ↓

cause The rule name is incorrectly spelled or the plugin isn't installed.

fix

npm install --save-dev eslint-plugin-no-function-declare-after-return and ensure the rule name is 'no-function-declare-after-return/no-function-declare-after-return'.

error ESLint: Configuration for rule 'no-function-declare-after-return' is unknown ↓

cause Used rule name without plugin prefix in flat config or missing plugin declaration.

fix

Add 'no-function-declare-after-return' to the plugins array and prefix the rule: 'no-function-declare-after-return/no-function-declare-after-return'.

Warnings

gotcha This rule enforces a stylistic preference; it does not prevent runtime errors because function declarations are hoisted. ↓

fix Use ESLint's 'no-unreachable' rule to catch truly unreachable code.

breaking Version 1.0.0 was the initial release; rules and plugin name may mismatch in early versions. ↓

fix Upgrade to >=1.0.0 and use the rule as described in the README.

deprecated The package name 'no-function-declare-after-return' used in install instructions may be mistaken for the plugin name; the plugin is imported as 'eslint-plugin-no-function-declare-after-return'. ↓

fix Always use 'no-function-declare-after-return' as the plugin name in .eslintrc, but the npm package name is the same.

Install

npm install eslint-plugin-no-function-declare-after-return

yarn add eslint-plugin-no-function-declare-after-return

pnpm add eslint-plugin-no-function-declare-after-return

Imports

plugin

wrong

// Incorrect: { "rules": { "no-function-declare-after-return": "error" } } (omits plugin name prefix)

correct

// In .eslintrc: { "plugins": ["no-function-declare-after-return"], "rules": { "no-function-declare-after-return/no-function-declare-after-return": "error" } }

The rule is namespaced under the plugin name, unlike built-in rules. Always use 'no-function-declare-after-return/no-function-declare-after-return'.

flat config (ESLint 9+)

wrong

// Incorrect: using .eslintrc style with flat config or importing incorrectly

correct

import noFunctionDeclareAfterReturn from 'eslint-plugin-no-function-declare-after-return';
export default [noFunctionDeclareAfterReturn.configs.recommended];

For ESLint 9+ flat config, import the plugin and spread its config. The recommended config includes the rule.

CommonJS require

wrong

// Incorrect: const plugin = require('eslint-plugin-no-function-declare-after-return/no-function-declare-after-return');

correct

const plugin = require('eslint-plugin-no-function-declare-after-return');
// In .eslintrc: plugins: ["no-function-declare-after-return"], rules: { ... }

Require the plugin package, not the rule file. The plugin object is exported as a default.

Quickstart

Configures ESLint to disallow function declarations after return, with a failing example.

// .eslintrc.js
module.exports = {
  plugins: ['no-function-declare-after-return'],
  rules: {
    'no-function-declare-after-return/no-function-declare-after-return': 'error',
  },
};

// Example file that will fail:
function foo() {
  return 1;
  function bar() { return 2; }
}