export async function tx(db, query) {
    const client = await db.connect()
    try {
        await client.query('BEGIN')
        try {
            await query(client)
            client.query('COMMIT')
        } catch(e) {
            client.query('ROLLBACK')
        }
    } finally {
        client.release()
    }
}

// Alternatively using an arrow function:

const tx = (db, query) => {
    const client = await db.connect()
    try {
        await client.query('BEGIN')
        try {
            await query(client)
            client.query('COMMIT')
        } catch(e) {
            client.query('ROLLBACK')
        }
    } finally {
        client.release()
    }
}

// Usage:
const pool = new Pool();
await tx(pool, async (txClient) => {
    // Do what you need to do within your transaction here..
    await txClient.query(`UPDATE users SET password = 'foo' WHERE username = 'bar'`);
    await txClient.query(`UPDATE users SET password = 'foo' WHERE username = 'baz'`);
});