Ensure currency atoms are loaded before sigil_M

`Money.Sigil` was calling `String.to_existing_atom/1` directly rather
than `Cldr.validate_currency/1`. Since currency codes are only loaded
and therefore the atoms materialized when `Cldr` is loaded this created
a situation whereby a valid currency code may raise an `agument error`.
`Money.Sigil` now correctly calls `Cldr.validate_currency/1` which
ensures the currency atoms are loaded before validation. Closes #46.

CHANGELOG.md

@@ -1,6 +1,12 @@
-# Changelog for Money v2.0.1
+# Changelog for Money v2.0.2
+
+This is the changelog for Money v2.0.2 released on January 18th, 2017.  For older changelogs please consult the release tag on [GitHub](https://github.com/kipcole9/money/tags)
+
+### Bug Fixes
+
+* `Money.Sigil` was calling `String.to_existing_atom/1` directly rather than `Cldr.validate_currency/1`.  Since currency codes are only loaded and therefore the atoms materialized when `Cldr` is loaded this created a situation whereby a valid currency code may raise an `agument error`.  `Money.Sigil` now correctly calls `Cldr.validate_currency/1` which ensures the currency atoms are loaded before validation.  Closes #46.
 
-This is the changelog for Money v2.0.1 released on January 16th, 2017.  For older changelogs please consult the release tag on [GitHub](https://github.com/kipcole9/money/tags)
+# Changelog for Money v2.0.1
 
 ### Bug Fixes
 

lib/money/sigil.ex

@@ -30,7 +30,13 @@ defmodule Money.Sigil do
   defp atomize(currency) do
     currency
     |> List.to_string()
-    |> String.upcase()
-    |> String.to_existing_atom()
+    |> validate_currency!
+  end
+
+  def validate_currency!(currency) do
+    case Money.validate_currency(currency) do
+      {:ok, currency} -> currency
+      {:error, {_exception, reason}} -> raise Money.UnknownCurrencyError, reason
+    end
   end
 end

mix.exs

@@ -1,7 +1,7 @@
 defmodule Money.Mixfile do
   use Mix.Project
 
-  @version "2.0.1"
+  @version "2.0.2"
 
   def project do
     [

test/money_test.exs

@@ -504,6 +504,19 @@ defmodule MoneyTest do
     assert m == Money.new!(:USD, 100)
   end
 
+  test "raise when a sigil function has an invalid currency" do
+    assert_raise Money.UnknownCurrencyError, ~r/The currency .* is invalid/, fn ->
+      Money.Sigil.sigil_M("42", [?A, ?B, ?C])
+    end
+  end
+
+  test "raise when a sigil has an invalid currency" do
+    import Money.Sigil
+    assert_raise Money.UnknownCurrencyError, ~r/The currency .* is invalid/, fn ->
+      ~M[42]ABD
+    end
+  end
+
   test "that we get a deprecation message if we use :exchange_rate_service keywork option" do
     Application.put_env(:ex_money, :exchange_rate_service, true)