Fix formatting a that has no key. Fixes #123

Author: kipcole9

CHANGELOG.md

@@ -1,6 +1,14 @@
+# Changelog for Money v5.5.1
+
+This is the changelog for Money v5.5.1 released on February 18th, 2021.  For older changelogs please consult the release tag on [GitHub](https://github.com/kipcole9/money/tags)
+
+### Bug Fixes
+
+* Fix formatting a `t:Money` that has no `:format_options` key. That can happen if re-hydrating a `t:Money` using `:erlang.binary_to_term/1` from an older version of `ex_money` that doesn't have the `:format_options` key in the struct.  Thanks to @coladarci. Fixes #123.
+
 # Changelog for Money v5.5.0
 
-This is the changelog for Money v5.5.0 released on ______, 2021.  For older changelogs please consult the release tag on [GitHub](https://github.com/kipcole9/money/tags)
+This is the changelog for Money v5.5.0 released on February 10th, 2021.  For older changelogs please consult the release tag on [GitHub](https://github.com/kipcole9/money/tags)
 
 ### Enhancements
 

lib/money.ex

@@ -701,19 +701,22 @@ defmodule Money do
 
   def to_string(%Money{} = money, options) when is_list(options) do
     default_options = [backend: Money.default_backend(), currency: money.currency]
+    format_options = Map.get(money, :format_options, [])
 
     options =
       default_options
-      |> Keyword.merge(money.format_options)
+      |> Keyword.merge(format_options)
       |> Keyword.merge(options)
 
     backend = options[:backend]
     Cldr.Number.to_string(money.amount, backend, options)
   end
 
   def to_string(%Money{} = money, %Cldr.Number.Format.Options{} = options) do
+    format_options = Map.get(money, :format_options, [])
+
     options =
-      money.format_options
+      format_options
       |> Map.new()
       |> Map.merge(options)
       |> Map.put(:currency, money.currency)

mix.exs

@@ -1,7 +1,7 @@
 defmodule Money.Mixfile do
   use Mix.Project
 
-  @version "5.5.0-dev"
+  @version "5.5.1"
 
   def project do
     [

test/money_test.exs

@@ -542,4 +542,9 @@ defmodule MoneyTest do
     assert Money.div!(money_with_options, 3).format_options == format_options
 
   end
+
+  test "to_string/2 on a Money that doesn't have a :format_options key" do
+    money = %{__struct__: Money, amount: Decimal.new(3), currency: :USD}
+    assert Money.to_string(money) == {:ok, "$3.00"}
+  end
 end