When starting processes during your tests, we should always prefer to use start_supervised!. It is hard to tell without further details, but it seems you’d have a Plug.Upload instance after casting, which one might use to retrieve the image, do whatever is needed (e. In other words, it helps guarantee that the state of one test is not going to interfere with the next one in case they depend on shared resources. After the castattachments/3 call, you get back a changeset that might be modified directly. The advantage of using start_supervised! is that ExUnit will guarantee that the registry process will be shutdown before the next test starts. It does the job of starting the KV.Registry process, by calling its start_link/1 function. The start_supervised! function was injected into our test module by use ExUnit.Case.

Any attributes we want to assign to the associated record we are saving. Ecto has two nifty methods for working with associated records in a changeset. buildassoc/3 takes in three arguments: The struct of the record we want to save.

Instead of starting the registry by hand by calling KV.Registry.start_link/1, we instead called the start_supervised!/2 function, passing the KV.Registry module. With a belongs to relationship, we can leverage Ecto’s buildassoc/3 function. There is one important difference between the setup block we wrote for KV.Registry and the one we wrote for KV.Bucket. Ecto is the go-to database toolkit in the Elixir ecosystem, usually used to interact with SQL databases like Postgres and MySQL.

In our example we are going to use /3 since users will only ever have one profile associated with them. Schemaless changesets make Ecto extremely useful to cast, validate and prune data even if it is not meant to be persisted to the database. Our test case first asserts there’s no buckets in our registry, creates a named bucket, looks it up, and asserts it behaves as a bucket. Your choice here affects the behavior of embed-specific functions like /4 and /3, so choose whichever is most appropriate to your use case. 1 Photo by Brooke Lark on Unsplash In our previous post we took a little look at the differences between some common changeset functions in Ecto.

Elixir ecto cast