`encore db conn-uri` command fails when using the `--test` flag

[carson-strella]

Steps to Reproduce

1. define a new DB via Encore, for example:

export const DB = new SQLDatabase("myDb", {
  migrations: {
    path: "./migrations",
  },
});

2. Call encore run, which creates the DB
3. Call encore db conn-uri myDb to get a valid connection string (this works!)
4. Call encore db conn-uri myDb --test to try and get the test connection string, instead get:

error: could not connect to the database for service myDb: rename db myDb to myDb_template: ERROR: database "myDb_template" already exists (SQLSTATE 42P04)

Additional Context

I'm using Prisma to manage my DB migrations, though I didn't need to use Prisma to get the minimum repro here.

Let me know if there's anything else I can add!

[shimonenator]

@carson-strella I've battled the same, until I realized that test DBs are ephemeral. Each time test re-runs, db url is new. When you run this command with --test it tries to give you the connection url by spinning up the DB, but since there's no test running the DB does not get spun down leading to this error message.

So while this is a bug in the code, if you're running into it you're likely going against the Encore's philosophy about test db in the first place.

[carson-strella]

@shimonenator, if that's the case, should the --test flag be removed entirely then? I'm not sure in what situation it would be expected to work.

Notably, if I leave my encore test process running, the command is still unsuccessful. Wouldn't you expect the current URI to be returned in that case?

[shimonenator]

@carson-strella I don't disagree with you that having --test flag raises questions, but I can't speak for the Encore's core team intentions here.

However, running encore test and encore db ... is creating two separate instances of encore, which is why I said you're going against the Encore's philosophy here. It helped me to understand this by logging the DB connection string and noticing that the port was different each time test re-ran. It also helps to look into your Docker Desktop and into Encore's namespaces concept, which helped me appreciate how much heavy lifting Encore is doing behind the scenes.