Better type support in Swift Client database requests

[tmcgann]

I like the Supabase swift client we have today but I think it would be so much better if it had better type support or could do some kind of type inference. For example, today I have a query like this:

client
      .from("some_table")
      .update([
        "some_column": "some_value",
      ])
      .eq("some_id", value: someUUID)
      .execute()

If the column names in my database change and I don't update the strings in this code then this request throws a runtime error instead of a compile time error.

It would be so much better if instead of allowing any arbitrary string in .from or .eq or even in the .update dictionary (or anything referencing database tables, columns, etc.) it could detect if that string was actually a valid column. I've seen this kind of thing done with ORMs in the TypeScript world and it's amazing DX. Even if you could give the client some type hints by passing in a model to the .from or to some kind of generic where it could then require you pass in the correct column names based on that model...that would be amazing. All your client requests would then be typed; no magic strings; compile time errors for the win. I'm already defining Codable DTOs anyway, so those could be used in the client requests as well when pushing data back to the database.

Example model:

struct SomeModelDTO: Identifiable, Codable {
  var id: UUID
  var createdAt: Date
  var updatedAt: Date
  var name: String
  
  enum CodingKeys: String, CodingKey {
    case id
    case createdAt = "created_at"
    case updatedAt = "updated_at"
    case name
  }
}

Example usage:

// BAD
client
      .from(SomeModelDTO.self)
      .update([
        "some_column": "some_value", // ERROR: Not a valid column name
      ])
      .eq("some_id", value: someUUID) // ERROR: Not a valid column name
      .execute()

// GOOD
client
      .from(SomeModelDTO.self)
      .update([
        SomeModelDTO.CodingKeys.name: "some_value",
      ])
      .eq(SomeModelDTO.CodingKeys.id, value: someUUID)
      .execute()

Open to other ideas (e.g. autogenerated models, etc.) but I'm desperate for a solution that will make my code more maintainable and leverage the advantages of the compiler/types.

I dropped a comment on the Swift OpenAPI generator discussion. That poses another interesting solution.