"ReferenceError: Cannot access 'Entity' before initialization" when running migrations

Issue type:

[x] question [x] bug report? [ ] feature request [ ] documentation issue

Database system/driver:

[ ] cordova [ ] mongodb [ ] mssql [ ] mysql / mariadb [ ] oracle [x] postgres [ ] cockroachdb [ ] sqlite [ ] sqljs [ ] react-native [ ] expo

TypeORM version:

[ ] latest [ ] @next [x] 0.2.24

Steps to reproduce or a small repository showing the problem:

Getting the following error when trying to add relations and then generate migrations:

Error during migration generation:
ReferenceError: Cannot access 'B' before initialization

Even with this incredibly simple example (classes in the same file):

@Entity()
export class A extends BaseEntity {
  @PrimaryGeneratedColumn('uuid')
  public id!: string;

  @OneToOne(
    () => B,
    b => b.a
  )
  public b!: B;
}

@Entity()
export class B extends BaseEntity {
  @PrimaryGeneratedColumn('uuid')
  public id!: string;

  @OneToOne(
    () => A,
    a => a.b
  )
  @JoinColumn()
  public a!: A;
}

This code compiles ~and runs~ fine, I just cannot run migrations for it.

Edit: I get the same error when starting my server.

My orm config is something like:

import { ConnectionOptions } from 'typeorm';

import * as entities from './entities';

export const ORM_CONFIG: ConnectionOptions = {
  type: 'postgres',
  url: process.env.DATABASE_URL,
  entities: Object.values(entities),
  logging: true,
};

I had to import my entities because I haven’t yet been able to get typeorm to pick them up at all when using paths; for example, ./entities/**/*.ts.

And here’s my tsconfig:

{
  "compilerOptions": {
    "strict": true,
    "noImplicitAny": true,
    "pretty": true,
    "sourceMap": true,
    "skipLibCheck": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "jsx": "react",
    "target": "es6",
    "moduleResolution": "node",
    "typeRoots": ["./node_modules/@types/", "./@types/"]
  },
  "include": ["./src/", "./@types/"]
}

[cacabo]

Ooh solution exists! https://github.com/typeorm/typeorm/issues/4190

[JakeSidSmith]

Okay, this now appears to work if I put the entities into separate modules and change my orm config to:

import * as fs from 'fs';
import * as path from 'path';
import { ConnectionOptions } from 'typeorm';

const ENTITIES_DIR = path.resolve(__dirname, 'entities');

const entities = fs
  .readdirSync(ENTITIES_DIR)
  .map(file => path.resolve(ENTITIES_DIR, file));

export const ORM_CONFIG: ConnectionOptions = {
  type: 'postgres',
  url: process.env.DATABASE_URL,
  entities,
  logging: true,
};

But this isn’t ideal. Can I not have my entities in the same file?