Typeorm: Migrations should each run in a separate transaction

[Waldo000000]

It seems that all migrations run in a single transaction (https://github.com/typeorm/typeorm/blob/master/src/migration/MigrationExecutor.ts). This can cause issues, for example:

1. Add a migration that creates a table.
2. Add a migration that runs CREATE INDEX CONCURRENTLY (PostgreSQL), to add an index to that table outside of the current transaction, using the workaround described in https://github.com/typeorm/typeorm/issues/1169.
3. Connect to and run migrations on an empty database

Expected result: Migrations succeed.
Actual result: Fails because the transaction that creates the table in the first migration _is still open and uncommitted_ when the second migration runs.

Unless there is a reason to use a single transaction for all migrations, I suggest using a separate transaction per migration, which should fix this issue.

[pleerock]

Fixed in the latest @next.
Now you can specify an option to the migration:run command and disable transaction:

migration:run -t=false

You can try it via npm i typeorm@next.