docs: improve docs/small error message tweak

lib/ash/doc_index/doc_index.ex

@@ -83,6 +83,37 @@ defmodule Ash.DocIndex do
     end
   end
 
+  def find_undocumented_items(doc_index) do
+    Enum.each(doc_index.extensions(), fn extension ->
+      Enum.each(
+        extension.module.sections(),
+        &find_undocumented_in_section(&1, [inspect(extension.module)])
+      )
+    end)
+  end
+
+  defp find_undocumented_in_section(section, path) do
+    find_undocumented_in_schema(section.schema(), [section.name() | path])
+    Enum.each(section.sections(), &find_undocumented_in_section(&1, [section.name() | path]))
+    Enum.each(section.entities(), &find_undocumented_in_entity(&1, [section.name() | path]))
+  end
+
+  defp find_undocumented_in_entity(entity, path) do
+    find_undocumented_in_schema(entity.schema(), [entity.name() | path])
+
+    Enum.each(entity.entities(), fn {_key, entities} ->
+      Enum.each(entities, &find_undocumented_in_entity(&1, [entity.name() | path]))
+    end)
+  end
+
+  defp find_undocumented_in_schema(schema, path) do
+    Enum.each(schema, fn {key, opts} ->
+      if !opts[:link] do
+        raise "Undocumented item #{Enum.reverse(path) |> Enum.join(".")}.#{key}"
+      end
+    end)
+  end
+
   # sobelow_skip ["Traversal.FileModule"]
   def read!(app, path) do
     app

lib/ash/flow/flow.ex

@@ -98,6 +98,9 @@ defmodule Ash.Flow do
             {:constrained, {:ok, nil}} ->
               {:cont, {:ok, Map.put(acc, arg.name, nil)}}
 
+            {:constrained, {:error, error}} ->
+              {:halt, {:error, error}}
+
             {:error, error} ->
               {:halt, {:error, error}}
           end

lib/ash/options_helpers.ex

@@ -38,7 +38,7 @@ defmodule Ash.OptionsHelpers do
     |> NimbleOptions.docs()
   end
 
-  @non_nimble_options [:hide, :as, :snippet]
+  @non_nimble_options [:hide, :as, :snippet, :links]
 
   defp sanitize_schema(schema) do
     Enum.map(schema, fn {key, opts} ->

lib/ash/resource/attribute.ex

@@ -37,11 +37,15 @@ defmodule Ash.Resource.Attribute do
   @schema [
     name: [
       type: :atom,
-      doc: "The name of the attribute."
+      doc: "The name of the attribute.",
+      links: []
     ],
     type: [
       type: :ash_type,
-      doc: "The type of the attribute."
+      doc: "The type of the attribute.",
+      links: [
+        modules: ["ash:module:Ash.Type"]
+      ]
     ],
     constraints: [
       type: :keyword_list,

lib/ash/type/type.ex

@@ -504,7 +504,7 @@ defmodule Ash.Type do
             |> Enum.with_index()
             |> Enum.reduce({[], []}, fn {item, index}, {items, errors} ->
               if is_nil(item) && not nil_items? do
-                {[item | items], [[message: "no nil/null values", index: index] | errors]}
+                {[item | items], [[message: "no nil values", index: index] | errors]}
               else
                 case apply_constraints(type, item, item_constraints) do
                   {:ok, value} ->