chore: require name for ash.codegen

lib/ash/resource/transformers/create_join_relationship.ex

@@ -1,9 +1,6 @@
 defmodule Ash.Resource.Transformers.CreateJoinRelationship do
   @moduledoc """
   Creates an automatically named `has_many` relationship for each many_to_many.
-
-  This will likely not be around for long, as our logic around many to many relationships
-  will update soon.
   """
   use Spark.Dsl.Transformer
 

lib/mix/tasks/ash.codegen.ex

@@ -6,6 +6,39 @@ defmodule Mix.Tasks.Ash.Codegen do
 
   @shortdoc "Runs all codegen tasks for any extension on any resource/api in your application."
   def run(argv) do
+    {name, argv} =
+      case argv do
+        ["-" <> _ | _] ->
+          {nil, argv}
+
+        [first | rest] ->
+          {first, rest}
+
+        [] ->
+          {nil, []}
+      end
+
+    {opts, _} =
+      OptionParser.parse!(argv,
+        strict: [
+          name: :string,
+          no_format: :boolean,
+          dry_run: :boolean,
+          check: :boolean,
+          drop_columns: :boolean
+        ]
+      )
+
+    if !opts[:name] && !opts[:dry_run] && !opts[:check] do
+      raise ArgumentError, """
+      Name must be provided when running `ash.codegen`, unless `--dry-run` or `--check` is also provided.
+
+      Please provide a name. for example:
+
+          mix ash.codegen add_feature_for_reticulating_splines #{Enum.join(argv, " ")}
+      """
+    end
+
     argv
     |> Ash.Mix.Tasks.Helpers.extensions!()
     |> Enum.map(fn extension ->