esbuild-plugin-typescript-decorators

0.1.0 verified Mon Apr 27 auth: no javascript

An ESBuild plugin that enables TypeScript decorator metadata emission (emitDecoratorMetadata) which ESBuild does not support natively. Version 0.1.0 is the initial release, with no further updates. It fills a gap for developers using ESBuild with decorators, as ESBuild skips type system features. This plugin ensures Reflect.getMetadata returns correct type information (e.g., design:type) during transpilation. It is a lightweight alternative to switching to tsc or ts-jest, but limited to emitDecoratorMetadata support only.

Common errors

error Error: [plugin: esbuild-decorators] Cannot find module 'typescript' ↓

cause Missing TypeScript as a peer dependency.

fix

Install typescript: npm install --save-dev typescript

error TypeError: esbuildDecorators is not a function ↓

cause Importing as default instead of named export or forgetting to call it.

fix

Use import { esbuildDecorators } from 'esbuild-plugin-typescript-decorators' and then in plugins: [esbuildDecorators()]

error Error: Reflect.getMetadata returns undefined even with plugin ↓

cause tsconfig.json missing emitDecoratorMetadata or experimentalDecorators.

fix

Set "experimentalDecorators": true and "emitDecoratorMetadata": true in tsconfig.

Warnings

gotcha ESBuild does not support decorators at all beyond basic transpilation; this plugin only adds emitDecoratorMetadata, not full decorator support (e.g., no proposal-stage decorators). ↓

fix Use a different tool like tsc or swc for full decorator support.

gotcha Plugin must be called as a function (esbuildDecorators()), not passed directly. ↓

fix Use esbuildDecorators() in plugins array.

deprecated Package has not been updated since v0.1.0; may not work with latest ESBuild versions (e.g., ESBuild v0.20+). ↓

fix Check compatibility; consider forking or using alternatives.

Install

npm install esbuild-plugin-typescript-decorators

yarn add esbuild-plugin-typescript-decorators

pnpm add esbuild-plugin-typescript-decorators

Imports

esbuildDecorators

wrong

const esbuildDecorators = require('esbuild-plugin-typescript-decorators').esbuildDecorators

correct

import { esbuildDecorators } from 'esbuild-plugin-typescript-decorators'

Named export only; no default export.

esbuildDecorators (as plugin)
wrong
```
plugins: [esbuildDecorators]
```
correct
```
plugins: [esbuildDecorators()]
```
Must call as function, it returns a plugin object.
esbuild
wrong
```
const esbuild = require('esbuild')
```
correct
```
import esbuild from 'esbuild'
```
CommonJS require fails because esbuild is ESM-only in recent versions.

Quickstart

Shows basic usage to bundle a TypeScript file with decorator metadata using ESBuild and the plugin.

import esbuild from 'esbuild'
import { esbuildDecorators } from 'esbuild-plugin-typescript-decorators'

await esbuild.build({
  entryPoints: ['src/index.ts'],
  outfile: 'dist/index.js',
  bundle: true,
  tsconfig: 'tsconfig.json', // must have "experimentalDecorators": true and "emitDecoratorMetadata": true
  plugins: [
    esbuildDecorators()
  ]
})