Allow partial filters on embedded resources in OpenAPI schema generation

[nallwhy]

Describe the bug

When generating filter schemas using AshJsonApi.OpenApi.raw_filter_type/2, filtering on embedded resources currently requires all attributes of the embedded struct to match. This means it’s not possible to query based on partial conditions (i.e., using at_path) for specific fields within the embedded resource.

%{
  "description" => "Filter results",
  "properties" => %{
    "bio" => %{
      "additionalProperties" => false,
      "properties" => %{
        "eq" => %{
          "additionalProperties" => false,
          "properties" => %{
            "birth" => %{
              "anyOf" => [
                %{
                  "description" => "Field included by default.",
                  "format" => "date",
                  "nullable" => true,
                  "type" => "string"
                },
                %{"type" => "null"}
              ]
            },
            "nationality" => %{
              "anyOf" => [
                %{
                  "description" => "Field included by default.",
                  "nullable" => true,
                  "type" => "string"
                },
                %{"type" => "null"}
              ]
            }
          },
          "type" => "object"
        }
      }
    }
  }
}

To Reproduce

Run AshJsonApi.OpenApi.raw_filter_type/2 with any resource that has embedded resource.

Expected behavior

To allow multiple at_path filters on an embedded resource, it seems necessary to pass a list of filters to Ash.Query.filter_input/2. Therefore, the filter type should be wrapped in an array in the generated JSON schema to properly support this use case.

Runtime

• Elixir version: 1.18
• Erlang version: 27
• OS: mac
• Ash version: 3.5.1
• any related extension versions: AshJsonAPI 1.4.22

Additional context

[zachdaniel]

I think we may need to solve this to some degree in Ash first. Specifically, I don't think we support turning nested paths for embeds into get_path.