Unable to use file path for loading entities and Entity Load Order

[thxmike]

Issue Description

Error when using TypeORM, and Typescript with folder path

Expected Behavior

As reported here
https://stackoverflow.com/questions/66735359/error-when-using-typeorm-and-typescript-with-folder-path
Entities should load without error.
Currently when using the following tsconfig

{
  "compilerOptions": {
    "target": "ES2020",
    "module":"ES2020",
    "esModuleInterop": true,
    "moduleResolution": "node",
    "strict": true,
    "declaration": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "outDir": "bin",
    "types": ["node"],
    "typeRoots": ["../node_modules/@types"],
    "sourceMap": true
  },
  "include": ["**/*.ts"],
  "exclude": ["tests", "node_modules", "lib", "bin", "dist"]
}

and package.json

{
  "name": "test-api",
  "version": "0.0.12",
  "description": "...",
  "license": "ISC",
  "author": "Me",
  "main": "server.js",
  "type": "module",
  "scripts": {
    "start": "node bin/server.js",
    "build": "npm i && tsc",
    "lint": "./node_modules/.bin/eslint --ignore-path .gitignore .",
    "test": "echo \"Error: currently no test specified\""
  },
  "dependencies": {
    "express": "^4.17.1",
    "mssql": "^6.3.1",
    "reflect-metadata": "^0.1.13",
    "syswide-cas": "^5.3.0",
    "typeorm": "^0.2.31",
    "uuid-mongodb": "^2.4.2"
  },
  "devDependencies": {
    "@types/node": "^14.14.35"
  }
}

I get the following error when loading the entities with a string file path - ${process.cwd()}/bin/models/entities/*.js

Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: ...\Projects\orders-api\bin\models\entities\Address.js
require() of ES modules is not supported.
require() of ...\Projects\orders-api\bin\models\entities\Address.js from ...\Projects\orders-api\node_modules\typeorm\util\DirectoryExportedClassesLoader.js is an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which defines all .js files in that package scope as ES modules.
Instead rename Address.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from ...
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1080:13)
at Module.load (internal/modules/cjs/loader.js:928:32)
at Function.Module._load (internal/modules/cjs/loader.js:769:14)
at Module.require (internal/modules/cjs/loader.js:952:19)
at require (internal/modules/cjs/helpers.js:88:18)
Instead rename Address.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from C:\Users\mrivera\Projects\orders-api\package.json.

I have tried different combinations of the tsconfig.json but no change. 

I load my connection options as follows

return createConnection({
name: "default",
type: "mssql",
host: this._server,
username: this._user_name,
password: this._password,
database: this._database,
extra: true,
options: {
isolation: "READ_UNCOMMITTED",
},
entities: [
${this._entity_path}/entities/*.js
],
})

Here is an example of one of the entities I use

import { Column, Entity, Index, OneToMany, PrimaryGeneratedColumn } from 'typeorm';

import { Patient } from './Patient.js';
import { PatientNextOfKin } from './PatientNextOfKin.js';

@Index("PK__Address__3213E83F7240D5FD", ["id"], { unique: true })
@entity("Address", { schema: "Orders" })
export class Address {
@PrimaryGeneratedColumn({ type: "int", name: "id" })
id!: number;

@column("nvarchar", { name: "line", length: 500 })
line!: string;

@column("nvarchar", { name: "line2", length: 100 })
line2!: string;

@column("nvarchar", { name: "city", length: 100 })
city!: string;

@column("nvarchar", { name: "state", length: 2 })
state!: string;

@column("nvarchar", { name: "zip", length: 10 })
zip!: string;

@OneToMany(() => Patient, (patient) => patient.address)
patients!: Patient[];

@OneToMany(
() => PatientNextOfKin,
(patientNextOfKin) => patientNextOfKin.address
)
patientNextOfKins!: PatientNextOfKin[];

}

I do not use a ormconfig.json since I cannot persist this data in my repo as these configuration values are load during runtime.

### Steps to Reproduce
tsc
node ..\bin\server.js


### Additional Context

As a work around, I collect each entity in an array and pass it into the connection options. However, I run into another issue which the runtime is unable to load the entities in the correct order which results in another runtime error

> file:///C:/Users/.../Projects/my-api/bin/models/entities/entity1.js:29 __metadata("design:type", Entity2) ^
> 
> ReferenceError: Cannot access 'Entity2' before initialization at file:///C:/Users/.../Projects/my-api/bin/models/entities/entity1.js:29:31 at ModuleJob.run (internal/modules/esm/module_job.js:152:23) at async Loader.import (internal/modules/esm/loader.js:166:24) at async Object.loadESM (internal/process/esm_loader.js:68:5)
>  and is documented here. 

https://stackoverflow.com/questions/66715166/referenceerror-with-typeorm-entity-and-onetomany

### Relevant Database Driver(s)
mssql
### Are you willing to resolve this issue by submitting a Pull Request?

Yes if I knew where to look.

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- [ ] Yes, I have the time, but I don't know how to start. I would need guidance.
- [ ] No, I don't have the time, although I believe I could do it if I had the time...
- [ ] No, I don't have the time and I wouldn't even know how to start.


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[kevin-lindsay-1]

I transpile my ts to a ./build/ folder, and i keep my entities in ./src/db/entities/.

Here's my config for entities which works fine:

createConnection({
  ...,
  entities: ['build/db/entities/*.js']
})

[thxmike]

Yes, in my post, I transpile to the bin directory, the "this._entity_path" variable includes bin in the path. i.e. bin/models/entities. This can be see in the error messages

[bartdorsey]

So this is happening because you are trying to output ES modules from the typescript compilation step, and down inside of DirectoryExportedClassesLoader.js It does uses require() to dynamically load the modules.

I'm not sure if there's an easy fix for TypeORM here. If they switch to await import() instead of require() for the dynamic loading of the entities, then it'll break for everyone NOT using ES modules in Node.

Unless it could do some introspection and check if require exists, and if it does, use the require function, else use the await import function.

[chetrit]

Same problem here, with an hybrid codebase (js/ts), this problem seems inevitable when updating ts-node to versions 10.x, I don't have any problem with ts-node 9.1.1 though.

[ChibiBlasphem]

This is pretty much problematic for any app which is on node 14 and higher and for which the runtime is fully modular.

EDIT: by the way import() syntax is supported for commonjs and ESModule and should not break anything as stated here (https://nodejs.org/api/esm.html#esm_import_expressions)

[cx690]

I meet the same problem,and I regist classes by this way.

import path from 'path';
import { fileURLToPath } from 'url';
import { createConnection } from 'typeorm';
const __dirname = path.dirname(fileURLToPath(import.meta.url));
const js_files = fs.readdirSync(path.resolve(__dirname, './entities')).filter((f) => {
    return f.endsWith('.js') || f.endsWith('.ts');
});//find all js or ts in entities dir

function* importSth() {
    for (const f of js_files) {
        yield import('./entities/' + f).then((res) => Object.values(res));//import all of them classes
    }
}
const entities = (await Promise.all([...importSth()])).flat();
createConnection({
        type: 'mysql',
        database: 'index',
        username: 'root', 
        password: '123456', 
        host: 'localhost', 
        entities, //regist
})

[justin-echternach]

try ... "allowSyntheticDefaultImports": true, in tsconfig.json