Make sure that Money.to_string! actually raises

CHANGELOG.md

@@ -1,3 +1,15 @@
+# Changelog for Cldr v3.4.3
+
+This is the changelog for Cldr v3.4.3 released on June 2nd, 2019.  For older changelogs please consult the release tag on [GitHub](https://github.com/kipcole9/cldr/tags)
+
+### Bug Fixes
+
+* Ensure `Money.to_string!/2` properly raises
+
+* Add specs for `Money.to_string/2` and `Money.to_string!/2`
+
+Thanks to @rodrigues for the report and PR.
+
 # Changelog for Cldr v3.4.2
 
 This is the changelog for Cldr v3.4.2 released on April 16th, 2019.  For older changelogs please consult the release tag on [GitHub](https://github.com/kipcole9/cldr/tags)

lib/money.ex

@@ -610,6 +610,8 @@ defmodule Money do
       {:ok, "1,234 US dollars"}
 
   """
+  @spec to_string(Money.t(), Keyword.t()) :: {:ok, String.t()} | {:error, {atom, String.t()}}
+
   def to_string(%Money{} = money, options \\ []) do
     default_options = [backend: Money.default_backend(), currency: money.currency]
     options = Keyword.merge(default_options, options)
@@ -655,9 +657,12 @@ defmodule Money do
       "1,234 US dollars"
 
   """
+  @spec to_string(Money.t(), Keyword.t()) :: String.t() | no_return()
+
   def to_string!(%Money{} = money, options \\ []) do
-    with {:ok, string} <- Money.to_string(money, options) do
-      string
+    case to_string(money, options) do
+      {:ok, string} -> string
+      {:error, {exception, reason}} -> raise exception, reason
     end
   end
 

mix.exs

@@ -1,7 +1,7 @@
 defmodule Money.Mixfile do
   use Mix.Project
 
-  @version "3.4.2"
+  @version "3.4.3"
 
   def project do
     [

test/money_test.exs

@@ -179,6 +179,19 @@ defmodule MoneyTest do
     money = Money.new(1234, :USD)
     assert Money.to_string(money) == {:ok, "$1,234.00"}
   end
+
+  test "to_string works via protocol" do
+    money = Money.new(1234, :USD)
+    assert to_string(money) == "$1,234.00"
+  end
+
+  test "to_string! raises if there is an error" do
+    money = Money.new(1234, :USD)
+
+    assert_raise Cldr.FormatCompileError, fn ->
+      Money.to_string!(money, format: "0#")
+    end
+  end
 
   test "adding two money structs with same currency" do
     assert Money.add!(Money.new(:USD, 100), Money.new(:USD, 100)) == Money.new(:USD, 200)