Reflect-metadata doesn't work for tsyringe

[i-void]

What version of Bun is running?

1.0.0+822a00c4d508b54f650933a73ca5f4a3af9a7983

What platform is your computer?

Linux 6.2.0-32-generic x86_64 x86_64

What steps can reproduce the bug?

• Create a simple app with bun init
• add reflect-metadata and tsyringe to dependencies
• modify index.ts like this

  
  // index.ts
  import 'reflect-metadata'
  import { container, singleton } from 'tsyringe'

@singleton() class A { constructor() { console.log('A') } }

container.resolve(A)

- modify package.json like this

{ "name": "simplest", "module": "index.ts", "type": "module", "scripts": { "start": "bun ./index.ts" }, "devDependencies": { "bun-types": "latest" }, "peerDependencies": { "typescript": "^5.0.0" }, "dependencies": { "reflect-metadata": "^0.1.13", "tsyringe": "^4.8.0" } }

- modify tsconfig like this

{ "compilerOptions": { "lib": ["ESNext"], "module": "esnext", "target": "esnext", "moduleResolution": "bundler", "moduleDetection": "force", "allowImportingTsExtensions": true, "noEmit": true, "composite": true, "strict": true, "downlevelIteration": true, "skipLibCheck": true, "jsx": "preserve", "allowSyntheticDefaultImports": true, "forceConsistentCasingInFileNames": true, "allowJs": true, "emitDecoratorMetadata": true, "experimentalDecorators": true, "types": [ "bun-types" // add Bun global ] } }

- run `bun start`

### What is the expected behavior?

It should print `A` to the console.

### What do you see instead?

$ bun ./index.ts 1 | "use strict"; 2 | Object.defineProperty(exports, "__esModule", { value: true }); 3 | const tslib_1 = require("tslib"); 4 | if (typeof Reflect === "undefined" || !Reflect.getMetadata) { 5 | throw new Error(tsyringe requires a reflect polyfill. Please add 'import "reflect-metadata"' to the top of your entry point.); ^ error: tsyringe requires a reflect polyfill. Please add 'import "reflect-metadata"' to the top of your entry point. at /home/cm/Programming/bun/simplest/node_modules/tsyringe/dist/cjs/index.js:5:10 at globalThis (/home/cm/Programming/bun/simplest/node_modules/tsyringe/dist/cjs/index.js:15:126) error: script "start" exited with code 1 (SIGHUP)

### Additional information

When I use 
`const { container, singleton } = await import('tsyringe')` instead of direct import. It works.

[m-salman-afzal]

Same here, was trying to just run the node project in bun to see how it works, but stuck at this.

[alexbechmann]

Same, this is a blocker for me!

[Murzbul]

Same here!

[woehrl01]

Fyi, the latest version where this worked, was bun 0.6.11 (at least the application could execute without failure)

[woehrl01]

@i-void I found the rootcause of this. The problem is that the .cjs module gets imported instead of the ejs.

It looks like that the resolution does not work anymore as documented here

workaround is to modify the tsyringe's package.json to either:

• Remove "main": "./dist/cjs/index.js"

or:

• Add an "export" like that:

"exports": {
    "require": "./dist/cjs/index.js",
    "import": "./dist/esm2015/index.js"
  },

patch-package is your friend.

diff --git a/node_modules/tsyringe/package.json b/node_modules/tsyringe/package.json
index 8a7ebb7..f653a10 100644
--- a/node_modules/tsyringe/package.json
+++ b/node_modules/tsyringe/package.json
@@ -2,7 +2,11 @@
   "name": "tsyringe",
   "version": "4.8.0",
   "description": "Lightweight dependency injection container for JavaScript/TypeScript",
-  "main": "dist/cjs/index.js",
+  "exports": {
+    "require": "./dist/cjs/index.js",
+    "import": "./dist/esm2015/index.js"
+  },
+  "main": "./dist/cjs/index.js",
   "module": "./dist/esm5/index.js",
   "es2015": "./dist/esm2015/index.js",
   "typings": "./dist/typings/index.d.ts",

Edit: just found that it's an explicit breaking change in 0.6.12

PR for tsyringe: https://github.com/microsoft/tsyringe/pull/232

[alexbechmann]

Nice @woehrl01 !

With that fix I am able to import, however tsyringe still doesn't work as there is seemingly no metadata emitted for the classes?

error: TypeInfo not known for "MyClass"

[woehrl01]

@alexbechmann yes, that's right. But the underlying issue for that is, that bun only does transpiling. I don't have the github issue at hand, but there was a clear statement that will likely not be implemented in the near future, because of the complexity.

Edit: I did some research, and it looks like that there is currently a branch by @dylan-conway open, to add this. So maybe this come in the near future. 😊

[i-void]

my workaround is to use https://www.npmjs.com/package/core-js for reflect. But for some libraries like typegraphql its reflect implementation is missing some methods. So I use 2 libraries together, core-js initialize the Reflect object and reflect-metada does the remainin job.

import "core-js";
import "reflect-metadata";

This bug is still annoying though just wanted to share this as a workaround.

[alexbechmann]

I have an example repo with tsyringe working using a fixed version of esbuild-plugin-tsc: https://github.com/alexbechmann/bun-metadata-workaround for anybody needing a quick workaround until the real issue is resolved.

It works because the plugin compiles any file with decorators with tsc and therefore emitting the correct metadata.

[alexbechmann]

Tsyringe works with latest canary for me, without any plugins

bun upgrade --canary

[Zikoat]

This should be fixed in Bun v1.0.3 🎉🎉🎉 See the blog post and https://github.com/oven-sh/bun/issues/4575 This issue can be closed @i-void

[jonnysamps]

Using bun 1.0.3 and this is still happening for me.

[alekseibaryshnikov]

Still facing this issue on 1.0.11. 😢

[SamuelGaona]

Same problem on v1.0.13

tried:

root tsconfig.json --ts-config-override (has no effect)

[JMDowns]

There's a nice way to fix this as a workaround:

Make a bunfig.toml file in your root directory, and make the contents something like preload = ["./reflect-metadata-import.ts"]

Inside of 'reflect-metadata-import.ts', the content should be import 'reflect-metadata';

Running bun start after doing this gives me 'A'.

[BrennanColberg]

Still broken for me—I could replicate the exact bug as reported—on Bun v1.0.20. Can confirm that @JMDowns' patch works, though this is obviously suboptimal.

[dylan-conway]

This bug is happening because bun is evaluating modules in the wrong order sometimes. minimal repro: index.mjs:

import "./foo.cjs"
import bar from "usesGlobalFoo.cjs"

foo.cjs:

globalThis.foo = "foo";

usesGlobalFoo.cjs:

console.log(globalThis.foo);
module.exports = "bar";

Running this with node will print "foo" from the console.log in usesGlobalFoo.cjs. bun will print undefined because foo.cjs has not been evaluated yet.

This breaks tsyringe because import "reflect-metadata" will not modify global Reflect before the reflect metadata methods are used

[dilbarov]

Confirmed, if I run bun --hot index.ts, make minimal edits to the code, bun rebuilds the build and the error is not reproduced

[fccoelho7]

any update on that?

[etorralba]

It works when importing reflect-metadata at the Top of Your Entry Point File. In other words, you need to add import 'reflect-metadata'; at the very top of your main entry point file (usually src/index.ts or src/app.ts).

[oblx]

I had a try today after upgrading to latest 1.1.18, import 'reflect-metadata' at the top of my entrypoint src/index.ts and still buggy.

Luckily the workaround provided by @JMDowns fixed this issue 👌

[oblx]

@TheAyes my current working setup using bun 1.1.21 and based on the previous answer :

./bunfig.toml

preload = ["./src/config/reflectMetadata.ts"]
sourcemap = "external"
tsconfig = "tsconfig.json"

./src/config/reflectMetadata.ts

import 'reflect-metadata';

I used to have import 'reflect-metadata'; in index.ts but it looks fine without. In both run and bundle commands.

Edit : my deepest apologies, there are no tests in this project 🤦‍♂️

[lipex360x]

@TheAyes my current working setup using bun 1.1.21 and based on the previous answer :

./bunfig.toml

preload = ["./src/config/reflectMetadata.ts"]
sourcemap = "external"
tsconfig = "tsconfig.json"

./src/config/reflectMetadata.ts

import 'reflect-metadata';

I used to have import 'reflect-metadata'; in index.ts but it looks fine without. In both run and bundle commands.

Edit : my deepest apologies, there are no tests in this project 🤦‍♂️

For some reason that I really have no idea about, after a lot of head scratching I managed to "solve" the problem of reflect metadata in tests

in the root of my tests directory, what I did was create a file app.spec.ts with the following content

import { beforeAll } from 'bun:test'

import { app } from '@/app'

beforeAll(() => app.mount('/', () => null))

It is very important that this file is in the ROOT of the directory and not inside other subdirectories for it to work.

Reason: Once again... I have no idea

app.ts content (using core-js and tsyringe for dependency injection )

import '@/infra/containers'
import 'core-js'

import { Hono } from 'hono'
import { logger } from 'hono/logger'

import { carRoutes } from './infra/routes'

const app = new Hono()
app.use(logger())

app.route('/car', carRoutes)

export { app }