TypeORM does not provide builtin transactional tests. If your tests write to a non in-memory database, probably you have to truncate or erase all your tables for every test case.

This package allows the creation of transactional contexts during the test, starting a transaction in the begining of the test and rolling back at the end. This is a faster solution than truncate/delete, once nothing is really written to disk.

npm install --save-dev typeorm-transactional-tests

Or with yarn:

npm install --save-dev typeorm-transactional-tests

Versions 1.x.x of this library is compatible with typeorm 0.2.x

Versions 2.x.x of this library is compatible with typeorm 0.3.x

To apply the transactional context with Jest, just start the context in an beforeEach block and finish it in an afterEach:

import {Connection, getConnection } from 'typeorm';
import { TransactionalTestContext } from 'typeorm-transactional-tests';

let connection: Connection;
let transactionalContext: TransactionalTestContext;

beforeEach(async () => {
    connection = getConnection();
    transactionalContext = new TransactionalTestContext(connection);
    await transactionalContext.start();    
});

afterEach(async () => {
    await transactionalContext.finish();
});

Also, it is possible to apply the context to all your tests using a global Jest setup file. Add a new file on your test folder:

import { TransactionalTestContext } from 'typeorm-transactional-tests'

// @ts-ignore
global.beforeEach(async () => await transactionalContext.start());

// @ts-ignore
global.afterEach(async () => await transactionalContext.finish());

And point the Jest configuration to it:

 "setupFilesAfterEnv": [
   "<rootDir>/test/support/transactionalContext.ts"
  ]