Introduce suspenders:db:migrate task

[stevepolitodesign]

Lifted from our dotfiles, this task runs the latest migration, rolls
it back, and runs it again in an effort to ensure it's reversible. More
context can be found in these comments.

Unfortunately, the following implementation did not work because Rake recognized
that it db:migrate was already invoked, so it wasn't invoked a second
time.

task migrate: ["db:migrate", "db:rollback", "db:migrate", "db:test:prepare"]

Instead, we needed to reenable the task manually.

[stevepolitodesign]

I tested this locally and it worked.

❯ bin/rails suspenders:migrate
== 20240220120804 CreateUsers: reverting ======================================
-- drop_table(:users)
   -> 0.0011s
== 20240220120804 CreateUsers: reverted (0.0034s) =============================

== 20240220120804 CreateUsers: migrating ======================================
-- create_table(:users)
   -> 0.0015s
== 20240220120804 CreateUsers: migrated (0.0015s) =============================

[crackofdusk]

What is the advantage of this approach vs bin/rails db:migrate:redo?

[stevepolitodesign]

What is the advantage of this approach vs bin/rails db:migrate:redo?

@crackofdusk this is a great question.

When there's a pending migration, db:migrate:redo simply runs the migration. It does not revert it, and run it again, which is what suspenders:migrate aims to do.

bin/rails db:migrate:status

 Status   Migration ID    Migration Name
--------------------------------------------------
  down    20240220120804  Create users

bin/rails db:migrate:redo
== 20240220120804 CreateUsers: migrating ======================================
-- create_table(:users)
   -> 0.0121s
== 20240220120804 CreateUsers: migrated (0.0122s) =============================

However, if the migration has been run, then db:migrate:redo will revert it, and migrate it again.

bin/rails db:migrate:status

 Status   Migration ID    Migration Name
--------------------------------------------------
   up     20240220120804  Create users

bin/rails db:migrate:redo
== 20240220120804 CreateUsers: reverting ======================================
-- drop_table(:users)
   -> 0.0009s
== 20240220120804 CreateUsers: reverted (0.0031s) =============================

== 20240220120804 CreateUsers: migrating ======================================
-- create_table(:users)
   -> 0.0008s
== 20240220120804 CreateUsers: migrated (0.0008s) =============================

This is in contrast to suspenders:migrate in that it will always run the latest migration, revert it, and run it again.

[mike-burns]

1. LGTM, pushing this into Suspenders makes some sense (though I still need the shell alias for most Boost projects).
2. Should it be called like suspenders:db:migrate? I worry that we might one day want a way to migrate part of Suspenders itself.