Postgres, Node, Jest - Splitting testes into two suites results in deadlock - node.js

Question

I have two suites of tests, one for Accounts and one for Transactions, accounts.spec.js and transactions.spec.js. I'm also using supertest.
When I run them in jest, I get the error error: deadlock detected.
But if I move all describe blocks to one single spec.js file, and run only that file in jest, I get no errors.
The Account router is:
accountRouter.js
router.get('/accounts', async (req, res) => {
const result = await pool.query('SELECT * FROM accounts')
if (result.rows.length > 0) {
return res.status(200).send({ accounts: result.rows })
} else {
return res.status(404).send({ msg: 'No Account Found' })
}
})
And the Account test file is:
accounts.spec.js
describe('Accounts', () => {
beforeAll(() => {
return pool.query('BEGIN')
})
afterAll(() => {
return pool.query('ROLLBACK')
})
afterEach(() => {
return pool.query('TRUNCATE accounts')
})
it('returns 200 and all accounts', async () => {
await request(app).post(`${apiURL}/accounts`).send({title: 'Investments',})
const response = await request(app).get(`${apiURL}/accounts`).send()
expect(response.status).toBe(200)
expect(response.body.accounts.length).toBe(1)
});
})
The Transactions router is:
transactionsRouter.js
router.get('/:id/deposit', async (req, res) => {
const id = req.params.id
const result = await pool.query('SELECT * FROM accounts WHERE acc_id = ($1)', [id])
if (result.rows.length > 0) {
return res.status(200).send({destinationAccount: result.rows[0]})
} else {
return res.status(404).send({validationErrors: {invalidId: 'Account Not Found'}})
})
And the Transactions test file is:
transactions.spec.js
describe('Transactions DEPOSIT', () => {
beforeAll(() => {
return pool.query('BEGIN')
})
afterAll(() => {
return pool.query('ROLLBACK')
})
afterEach(() => {
return pool.query('TRUNCATE accounts')
})
afterEach(() => {
return pool.query('TRUNCATE transactions')
})
it('DEPOSIT returns 200 OK and account by id', async () => {
const insertMockAccountQuery = 'INSERT INTO accounts (title) VALUES ($1) RETURNING acc_id, title, budget';
const mockAccount = await pool.query(insertMockAccountQuery, [title])
const existingAccount = mockAccount.rows[0];
const response = await request(app).get(`${apiURL}/transactions/${existingAccount.acc_id}/deposit`).send();
expect(response.status).toBe(200);
expect(response.body.destinationAccount).toEqual(existingAccount);
})
});
Can anyone help me figure out the problem, please?
Thanks

Answer 1

Jest runs tests from one describe sequentially. Whereas runs tests from multiple files simultaneously.
In order to run all the tests sequentially the CLI flag --runInBand could be used.
More details here:
Are tests inside one file run in parallel in Jest?