eslint-plugin-reflect-metadata

ESLint plugin to ensure reflect-metadata is imported before any other imports.

Why?

reflect-metadata must be loaded before any code that relies on decorator metadata. If another module is imported first and uses decorators, the metadata won't be available. This plugin enforces that reflect-metadata (or reflect-metadata/lite) always appears as the very first import in your entry files.

Installation

npm install --save-dev eslint-plugin-reflect-metadata

Usage

Add the recommended configuration to your eslint.config.mjs:

import reflectMetadata from 'eslint-plugin-reflect-metadata'

export default [
  reflectMetadata.configs.recommended,
  // ...your other configs
]

Or configure the rule manually:

import reflectMetadata from 'eslint-plugin-reflect-metadata'

export default [
  {
    plugins: {
      'reflect-metadata': reflectMetadata,
    },
    rules: {
      'reflect-metadata/reflect-metadata-first': 'error',
    },
  },
]

Rules

reflect-metadata/reflect-metadata-first

Ensures that reflect-metadata or reflect-metadata/lite is imported before any other import in the file.

Incorrect:

import { Injectable } from '@nestjs/common'
import 'reflect-metadata' // Error: must be first

const express = require('express')
require('reflect-metadata') // Error: must be first

Correct:

import 'reflect-metadata'
import { Injectable } from '@nestjs/common'

require('reflect-metadata')
const express = require('express')

Both ESM import statements and CommonJS require() calls are supported.

Requirements

• Node.js >= 20.0.0
• ESLint >= 8.0.0

License

MIT