Syntax errors when using union with first/limit in 1.0.4

Environment

Knex version: 1.0.4 Database + version: PostgreSQL 13.4 OS: Debian

Bug

In 1.0.4 the behavior (order and wrapping) of union changed causing queries that previously worked to generate syntax errors.

One example is:

const results = await knex('accounts')
  .select('last_name')
  .unionAll(function () {
    this.select('last_name').from('accounts');
  })
  .first();
expect(results).to.eql({ last_name: 'User' });

Which in 1.0.4 gives error: select "last_name" from "accounts" limit $1 union all select "last_name" from "accounts" - syntax error at or near "union".

But in 1.0.3 it generates select "last_name" from "accounts" union all select "last_name" from "accounts" limit ?.

Another query that fails is

const results = await knex
  .unionAll(
    function () {
      this.select('last_name').from('accounts');
    },
    function () {
      this.select('last_name').from('accounts');
    },
    true
  )
  .first();
expect(results).to.eql({ last_name: 'User' });

with error: (select "last_name" from "accounts") union all (select "last_name" from "accounts") (limit $1) - syntax error at or near "("

I believe this change is introduced in https://github.com/knex/knex/pull/5030. Is this new behavior intended and we should rewrite our union queries?

This following is working, so it’s not that hard to update the queries but it seems like a breaking change?

const results = await knex
  .unionAll(
    function () {
      this.select('last_name').from('accounts');
    },
    function () {
      this.select('last_name').from('accounts');
    }
  )
  .first();

[OlivierCavadenti]

Sorry for the wait, and thanks for all examples guys. I have find how to fix it and I added a lot of unit tests but still need more tests. I will push tomorrow at the end of day.

[OlivierCavadenti]

@fnatte @wa11a I will fix it as soon as possible (today or tomorrow).