Dump to map if dump/2 is called for embedded_dump

See [papertrail issue](izelnakri/paper_trail#230).

Papertrail calls `Ecto.embedded_dump/2` for all schemas, not
just embedded schemas. This commit detects if `dump/2` is called
from `Ecto.embedded_dump/2` and if so returns a map instead of
the usual tuple.

CHANGELOG.md

@@ -2,6 +2,14 @@
 
 **Note** That `money_sql` is supported on Elixir 1.11 and later only.
 
+## Money_SQL v1.11.0
+
+This is the changelog for Money_SQL v1.11.0 released on January 19th, 2023.
+
+### Enhancements
+
+* When dumping a `Money.Ecto.Composite.Type`, detect if `dump/3` is being called by `Ecto.Type.embedded_dump/2`. If it is, then return a map that can be serialized to JSON. If it isn't (most cases) then return the tuple to be serialized to Postgres.  See [papertrail issue](https://github.com/izelnakri/paper_trail/issues/230).
+
 ## Money_SQL v1.10.2
 
 This is the changelog for Money_SQL v1.10.2 released on December 13th, 2023.

lib/money/ecto/money_ecto_composite_type.ex

@@ -64,8 +64,12 @@ if Code.ensure_loaded?(Ecto.Type) do
     @impl Ecto.ParameterizedType
     def dump(money, dumper \\ nil, params \\ [])
 
-    def dump(%Money{} = money, _dumper, _params) do
-      {:ok, {to_string(money.currency), money.amount}}
+    def dump(%Money{} = money, dumper, _params) do
+      if embedded_dump(dumper) do
+        Money.Ecto.Map.Type.dump(money)
+      else
+        {:ok, {to_string(money.currency), money.amount}}
+      end
     end
 
     def dump(nil, _, _) do
@@ -76,6 +80,24 @@ if Code.ensure_loaded?(Ecto.Type) do
       :error
     end
 
+    # Detects if we are being called on behalf the embedded dumper.
+    # In this case, we want to produce a map that can be serialized
+    # to JSON. See [papertrail issue](https://github.com/izelnakri/paper_trail/issues/230)
+
+    defp embedded_dump(nil) do
+      false
+    end
+
+    defp embedded_dump(dumper) do
+      case Function.info(dumper, :name) do
+        {:name, :"-embedded_dump/3-fun-0-"} ->
+          Function.info(dumper, :module) == {:module, Ecto.Type}
+
+        _other ->
+          false
+      end
+    end
+
     # Casting in changesets
 
     def cast(money) do
@@ -145,6 +167,15 @@ if Code.ensure_loaded?(Ecto.Type) do
       :error
     end
 
+    # embed_as is set to :dump because if it is set to
+    # `:self` then `cast/2` will be called when loading. And
+    # since casting is locale-sensitive, the results may
+    # not be correct due to variations in the decimal and grouping
+    # separators for different locales. This is because when casting
+    # we don't know if the data is coming from user input (and therefore should
+    # be locale awware) or from some JSON serialization (in which
+    # case it should not be locale aware).
+
     def embed_as(term), do: embed_as(term, [])
 
     @impl Ecto.ParameterizedType

mix.exs

@@ -1,7 +1,7 @@
 defmodule Money.Sql.Mixfile do
   use Mix.Project
 
-  @version "1.10.2"
+  @version "1.11.0"
 
   def project do
     [

test/money_ecto_test.exs

@@ -87,6 +87,23 @@ defmodule Money.Ecto.Test do
         assert customer.revenue == Money.new(:EUR, "12345,67")
       end)
     end
+
+    test "dump a money struct with Ecto.embedded_dump/3" do
+      organization = %Organization{payroll: Money.new(:USD, "100.23")}
+      dumped = Ecto.embedded_dump(organization, :json)
+
+      assert dumped == %{
+        name: nil,
+        value: %{"amount" => "0", "currency" => "USD"},
+        payroll: %{"amount" => "100.23", "currency" => "USD"},
+        tax: nil,
+        revenue: %{"amount" => "0", "currency" => "AUD"},
+        employee_count: nil,
+        customers: [],
+        inserted_at: nil,
+        updated_at: nil
+      }
+    end
   end
 
   for ecto_type_module <- [Money.Ecto.Composite.Type, Money.Ecto.Map.Type] do