Use new, separate :ecto_on_writable_violation to not pollute :ecto_fields

Author: green-david

lib/ecto/schema.ex

@@ -525,6 +525,7 @@ defmodule Ecto.Schema do
       Module.register_attribute(__MODULE__, :ecto_autogenerate, accumulate: true)
       Module.register_attribute(__MODULE__, :ecto_autoupdate, accumulate: true)
       Module.register_attribute(__MODULE__, :ecto_redact_fields, accumulate: true)
+      Module.register_attribute(__MODULE__, :ecto_on_writable_violation, accumulate: true)
     end
   end
 
@@ -2078,6 +2079,8 @@ defmodule Ecto.Schema do
         raise ArgumentError, "autogenerated fields must always be writable"
       end
 
+      Module.put_attribute(mod, :ecto_on_writable_violation, {name, on_writable_violation})
+
       if pk? do
         Module.put_attribute(mod, :ecto_primary_keys, name)
       end
@@ -2086,7 +2089,7 @@ defmodule Ecto.Schema do
         Module.put_attribute(mod, :ecto_query_fields, {name, type})
       end
 
-      Module.put_attribute(mod, :ecto_fields, {name, {type, {writable, on_writable_violation}}})
+      Module.put_attribute(mod, :ecto_fields, {name, {type, writable}})
     end
   end
 
@@ -2376,6 +2379,7 @@ defmodule Ecto.Schema do
     autoupdate = Module.get_attribute(module, :ecto_autoupdate) |> Enum.reverse()
     read_after_writes = Module.get_attribute(module, :ecto_raw) |> Enum.reverse()
     autogenerate_id = Module.get_attribute(module, :ecto_autogenerate_id)
+    on_writable_violation = Module.get_attribute(module, :ecto_on_writable_violation)
 
     struct_fields = Module.get_attribute(module, :ecto_struct_fields) |> Enum.reverse()
     derive = Module.get_attribute(module, :derive)
@@ -2392,7 +2396,7 @@ defmodule Ecto.Schema do
       end
 
     load =
-      for {name, {type, {_writable, _on_writable_violation}}} <- fields do
+      for {name, {type, _writable}} <- fields do
         if alias = field_sources[name] do
           {name, {:source, alias, type}}
         else
@@ -2401,17 +2405,17 @@ defmodule Ecto.Schema do
       end
 
     dump =
-      for {name, {type, {writable, _on_writable_violation}}} <- fields do
+      for {name, {type, writable}} <- fields do
         {name, {field_sources[name] || name, type, writable}}
       end
 
     field_sources_quoted =
-      for {name, {_type, {_writable, _on_writable_violation}}} <- fields do
+      for {name, {_type, _writable}} <- fields do
         {[:field_source, name], field_sources[name] || name}
       end
 
     types_quoted =
-      for {name, {type, {_writable, _on_writable_violation}}} <- fields do
+      for {name, {type, _writable}} <- fields do
         {[:type, name], Macro.escape(type)}
       end
 
@@ -2435,7 +2439,7 @@ defmodule Ecto.Schema do
     embed_names = Enum.map(embeds, &elem(&1, 0))
 
     updatable =
-      for {name, {_, {writable, _on_writable_violation}}} <- fields, reduce: {[], []} do
+      for {name, {_, writable}} <- fields, reduce: {[], []} do
         {keep, drop} ->
           case writable do
             :always -> {[name | keep], drop}
@@ -2444,19 +2448,14 @@ defmodule Ecto.Schema do
       end
 
     insertable =
-      for {name, {_, {writable, _on_writable_violation}}} <- fields, reduce: {[], []} do
+      for {name, {_, writable}} <- fields, reduce: {[], []} do
         {keep, drop} ->
           case writable do
             :never -> {keep, [name | drop]}
             _ -> {[name | keep], drop}
           end
       end
 
-    on_writable_violation =
-      for {name, {_, {_writable, on_writable_violation}}} <- fields do
-        {name, on_writable_violation}
-      end
-
     single_arg = [
       {[:dump], dump |> Map.new() |> Macro.escape()},
       {[:load], load |> Macro.escape()},