Dang it! I ran into import cycles with shared test utilities again. :-( Either I have to copy this function to set up an in-memory test storage across packages or I have to put it in the storage package itself and guard it with a build tag that is only used in tests (otherwise I end up with this function in my production binary as well). I don’t like any of the alternatives. :-(

@lyse@lyse.isobeef.org OK. So how I have worked things like this out is to have the interface in the root package from the implementations. The interface doesn’t need to be tested since it’s just a contract. The implementations don’t need to import storage.Storage

• storage/ defines the Storage interface (no tests!)
  
  • storage/sqlite for the sqlite implementation tests for sqlite directly
    
  • storage/ram for the ram implementation and tests for RAM directly
    
• controller/ can now import both storage and the implementation as needed.
  

So now I am guessing you wanted the RAM test for testing queries against sqlite and have it return some query response?

For that I usually would register a driver for SQL that emulates sqlite. Then it’s just a matter of passing the connection string to open the registered driver on setup.

https://github.com/glebarez/go-sqlite?tab=readme-ov-file#connection-string-examples

re reading so NewRAMStorage(…) is just something that setups your storage and initial data.. that can probably live with storage/sqlite. The point is the storage package does not import the implementations of storage.Storage It just defines the contract for things that use that interface. Now storage/sqlite CAN import storage and not have a circle dep.

It kinda works in reverse for import directions. usually you have your root package that imports things from deeper in the directory structures.. but for the case of interfaces it reverses where the deeper can import from parents but parents cannot import from children.

- app < storage
      < storage/sqlite
      < controller < storage
                   < storage/sqlite
 
- sqlite < storage

- storage X storage/sqlite