Ash FrameworkAF
Ash Framework•9mo ago•
4 replies
adonig

Correct Way to Display Spark.Error.DslError?

Hi! I’m writing a custom DSL extension and I’m struggling with making Spark.Error.DslError show up in the right place.

I followed patterns from core Ash code (like default_accept.ex and verify_identities.ex), and also looked at extensions like Ash Cloak. Here's what I did in my verifier:

  @impl true
  def verify(dsl_state) do
    inferred_attrs = InferredAttributes.Info.inferred_attributes(dsl_state)

    for attr <- inferred_attrs do
      if !Ash.Resource.Info.attribute(dsl_state, attr.name) do
        raise Spark.Error.DslError,
          module: Spark.Dsl.Verifier.get_persisted(dsl_state, :module),
          message: "All inferred attributes must be attributes. Got: #{inspect(attr.name)}",
          path: [:inferred_attributes, attr.name]
      end
    end

    :ok
  end


This seems not to raise, so I tried again this time in the transformer code:

  @impl true
  def transform(dsl_state) do
    module = Spark.Dsl.Transformer.get_persisted(dsl_state, :module)
    inferred_attrs = InferredAttributes.Info.inferred_attributes(dsl_state)

    Enum.reduce_while(inferred_attrs, {:ok, dsl_state}, fn attr, {:ok, dsl_state} ->
      attribute = Ash.Resource.Info.attribute(dsl_state, attr.name)

      if !attribute do
        raise Spark.Error.DslError,
          module: module,
          message: "No attribute called #{attr.name} found",
          path: [:inferred_attributes, attr.name]
      end

      if attribute.primary_key? do
        raise Spark.Error.DslError,
          module: module,
          message: "Cannot infer primary key attribute",
          path: [:inferred_attributes, attr.name]
      end

      {:cont, {:ok, dsl_state}}
    end)
  end


This raises as expected, but the error isn't tied to the DSL location. It does show up, but only on line 1 of the module.

Is there a recommended way to raise Spark.Error.DslError so that it points you to the invalid DSL section or field?

Any help or examples appreciated! 🙏
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