Needs test/migrations test

@Shinigami92 check it out. I fixed the renameIndex and removed the alterIndex method.I just don't know how to use reverse in migration tests.There's no examples using on down. If u gimme the answer I'll use it.

test/migrations/098_rename_index.js

Hey @beterrabaA, thanks for the update! 🙌

You don't need to call reverse manually — and you actually shouldn't write a down at all here. When a migration exports only up and every operation in it is reversible, node-pg-migrate auto-generates the down for you by calling each operation's .reverse in reverse order.

Both operations you use are reversible:

• createIndex.reverse → dropIndex
• renameIndex.reverse → the one you just added 🎉

There are already examples of this pattern in the test suite that omit down entirely, e.g. test/migrations/006_table_rename.js:

export const up = (pgm) => {
  pgm.renameTable('t2', 't2r');
};

So test/migrations/098_rename_index.js can be simplified to just:

export const up = (pgm) => {
  pgm.createIndex('t1', ['nmbr'], { name: 'idxfoo' });
  pgm.renameIndex('idxfoo', 'quxfoo');
};

The auto-generated down will then run the reverses in reverse order:

ALTER INDEX "quxfoo" RENAME TO "idxfoo";
DROP INDEX "idxfoo";

This is also better than the current hand-written down: right now down only renames quxfoo back to idxfoo and leaves the created index behind, so it isn't a true inverse of up. The auto-reverse drops it too.

One last thing: after this change the integration snapshots need refreshing (the migrations-down.*.stdout.log files), since the down output now includes the DROP INDEX. You can update them with the test runner's update flag.