node-postgres/packages/pg-cursor/test/transactions.js

const assert = require('assert');
const Cursor = require('../');
const pg = require('pg');

describe('transactions', () => {
  it('can execute multiple statements in a transaction', async () => {
    const client = new pg.Client();
    await client.connect();
    await client.query('begin');
    await client.query('CREATE TEMP TABLE foobar(id SERIAL PRIMARY KEY)');
    const cursor = client.query(new Cursor('SELECT * FROM foobar'));
    const rows = await new Promise((resolve, reject) => {
      cursor.read(10, (err, rows) => (err ? reject(err) : resolve(rows)));
    });
    assert.strictEqual(rows.length, 0);
    await client.query('ALTER TABLE foobar ADD COLUMN name TEXT');
    await client.end();
  });

  it('can execute multiple statements in a transaction if ending cursor early', async () => {
    const client = new pg.Client();
    await client.connect();
    await client.query('begin');
    await client.query('CREATE TEMP TABLE foobar(id SERIAL PRIMARY KEY)');
    const cursor = client.query(new Cursor('SELECT * FROM foobar'));
    await new Promise((resolve) => cursor.close(resolve));
    await client.query('ALTER TABLE foobar ADD COLUMN name TEXT');
    await client.end();
  });

  it('can execute multiple statements in a transaction if no data', async () => {
    const client = new pg.Client();
    await client.connect();
    await client.query('begin');
    // create a cursor that has no data response
    const createText = 'CREATE TEMP TABLE foobar(id SERIAL PRIMARY KEY)';
    const cursor = client.query(new Cursor(createText));
    const err = await new Promise((resolve) => cursor.read(100, resolve));
    assert.ifError(err);
    await client.query('ALTER TABLE foobar ADD COLUMN name TEXT');
    await client.end();
  });
});