typeorm: Cannot read property 'connect' of undefined

Issue type:

[ ] 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:

[x ] latest [ ] @next [ ] 0.x.x (or put your version here)

Steps to reproduce or a small repository showing the problem:

Configuration Options

export const test: Pool = {
  default: {
    name: 'default',
    type: 'postgres',
    host: 'localhost',
    port: 5432,
    username: 'test',
    password: '',
    database: 'main_test',
    logging: false,
    synchronize: true,
    migrations: ['db/migration/**/*{.ts,.js}'],
    subscribers: ['db/subscriber/**/*{.ts,.js}'],
    entities: ['dist/**/*.entity{.ts,.js}', 'app/**/*.entity{.ts,.js}'],
    cli: {
      migrationsDir: 'db/migration',
      subscribersDir: 'db/subscriber',
      entitiesDir: '',
    },
  },
};

Code

import supertest from 'supertest';
import { createServer } from 'http';
import { createConnection, getConnection } from 'typeorm';
import { test } from '../../config/connections';
import app from '../../app';

describe('Category - Testing', () => {
  beforeEach(async () => createConnection(test.default));
  afterEach(async () => getConnection('default').close());

  const testServer = supertest(createServer(app));

  it('responds with status code 200', async () => {
    const x = async () => {
      try {
        await testServer.get('/categories');
      } catch (err) {
        console.log(err);
      }
    };
    expect(x).toThrow();
  });
});

Error

TypeError: Cannot read property 'connect' of undefined
        at /Users/Stephano/Development/code-basket/application_6374/src/driver/postgres/PostgresDriver.ts:774:25
        at new Promise (<anonymous>)
        at PostgresDriver.Object.<anonymous>.PostgresDriver.obtainMasterConnection (/Users/Stephano/Development/code-basket/application_6374/src/driver/postgres/PostgresDriver.ts:773:16)
        at PostgresQueryRunner.Object.<anonymous>.PostgresQueryRunner.connect (/Users/Stephano/Development/code-basket/application_6374/src/driver/postgres/PostgresQueryRunner.ts:90:58)
        at PostgresQueryRunner.<anonymous> (/Users/Stephano/Development/code-basket/application_6374/src/driver/postgres/PostgresQueryRunner.ts:163:55)