ESLint Plugin Handlebars

1.0.4 verified Fri May 01 auth: no javascript

An ESLint plugin for linting Handlebars templates, version 1.0.4. It enforces consistent formatting and validates template syntax, including block spacing, quotes, indentation, and closing tags. Provides recommended and strict configurations. All rules are auto-fixable except no-missing-closing-tag. Requires ESLint >=8.57.0 and Node.js >=18.18.0. Unlike general formatters, it targets Handlebars-specific syntax errors and style issues.

Common errors

error Error: Failed to load plugin 'handlebars' declared in 'plugins': Cannot find module 'eslint-plugin-handlebars' ↓

cause Missing npm install or incorrect import path in flat config.

fix

Run npm install eslint-plugin-handlebars --save-dev and restart ESLint.

error TypeError: plugins must be an object, a string, or a function ↓

cause Using array syntax ['handlebars'] in flat config instead of object.

fix

Change to plugins: { handlebars } (object with key matching the import).

error ReferenceError: require is not defined in ES module scope ↓

cause Using require() in an ESM project.

fix

Replace const handlebars = require('eslint-plugin-handlebars') with import handlebars from 'eslint-plugin-handlebars'.

Warnings

breaking ESM-only: require() not supported. Must use import syntax. ↓

fix Switch to ESM: set "type": "module" in package.json and use import statements.

breaking Requires ESLint >=8.57.0. Older ESLint versions incompatible. ↓

fix Upgrade ESLint to >=8.57.0.

breaking Flat config only; legacy .eslintrc configs not supported. ↓

fix Migrate to flat config using eslint.config.js.

gotcha All rules are auto-fixable except no-missing-closing-tag. ↓

fix Run eslint with --fix for auto-fixable rules; manually fix missing closing tags.

gotcha Plugin name in flat config must match the import variable. Use 'handlebars' as plugin key. ↓

fix Set plugins: { handlebars } not plugins: ['handlebars'].

Install

npm install eslint-plugin-handlebars

yarn add eslint-plugin-handlebars

pnpm add eslint-plugin-handlebars

Imports

default

wrong

const handlebars = require('eslint-plugin-handlebars')

correct

import handlebars from 'eslint-plugin-handlebars'

ESM-only; CommonJS require is not supported. ESLint flat config requires ESM imports.

defineConfig
wrong
```
const { defineConfig } = require('eslint/config')
```
correct
```
import { defineConfig } from 'eslint/config'
```
defineConfig is part of ESLint's flat config API; not available in legacy config.
plugins
wrong
```
plugins: ['handlebars']
```
correct
```
plugins: { handlebars }
```
In flat config, plugins are objects, not strings. The key is the namespace for rules.

Quickstart

Flat config example that enables all rules with error level, demonstrating recommended strict setup.

// eslint.config.js
import { defineConfig } from "eslint/config";
import handlebars from "eslint-plugin-handlebars";

export default defineConfig([
  {
    plugins: {
      handlebars,
    },
    rules: {
      "handlebars/block-spacing": "error",
      "handlebars/consistent-quotes": ["error", "double"],
      "handlebars/expression-spacing": "error",
      "handlebars/indentation": ["error", 2],
      "handlebars/no-missing-closing-tag": "error",
      "handlebars/no-multiple-empty-lines": ["error", { max: 1 }],
      "handlebars/no-trailing-spaces": "error",
    },
  },
]);