Creating multiple many:many relationships can lead to silent failures to migrate or reset database

[AdamIsrael]

Description

I'm learning Loco with a pet project. I noticed that my latest migration wasn't generating the expected table, so I manually dropped my tables (including the migration table) and attempted to recreate them. I found that the tables were not being created when I ran cargo loco db migrate or cargo loco db reset.

What I ended up discovering is that the generate model is creating boilerplate code that was re-using a primary key index name. When migrate or reset ran, postgresql logged the message ERROR: relation "idx-refs-pk" already exists and aborts the transaction.

Because two migrations are attempting to use the same primary key name of idx-refs-pk, the second migration will fail silently, which seems to abort the entire transaction.

To Reproduce

# Create a fresh Saas project
loco new

# Create a "Movies" scaffold 
cargo loco generate scaffold movies name:string^

# Create a many:many relationship, which creates a pkey of "idx-refs-pk"
cargo loco generate model --link movies_actors user:references movie:references

# Do the same thing, but for tv
cargo loco generate scaffold tvshows name:string^

# Create another many:many, but for tv shows. It also tries to use a pkey of "idx-refs-pk"
cargo loco generate model --link tvshows_actors user:references tvshow:references

Expected Behavior

A clear and concise description of what you expected to happen.

1. The generated migration uses a unique primary key index name, like idx-movies-actors-pk.
2. When running cargo loco db migrate or cargo loco db reset, if there is a failure to create, a clear error message is returned to the user.

Environment:

MacOS 14.2.1
Rust 1.75.0

Additional Context

I suspect that the migration is running within a single transaction, so the last migration causes the entire migration to fail, which is why dropping all tables and re-running the migration resulted in no tables being recreated.

demo.zip

[jondot]

checking

[jondot]

Thanks, added a fix for it. Your bug report was very detailed and it allowed me to find the issue very quickly, thanks! ❤️