Allow nil to be set as default currency

CHANGELOG.md

@@ -5,6 +5,7 @@
 - Allow monetizing methods with kwargs
 - Fix money_only_cents for negative money
 - BREAKING CHANGE: Drop support for Ruby < 3 and Rails < 6.1
+- Allow `nil` to be set as the default currency
 
 ## 1.15.0
 

lib/money-rails/configuration.rb

@@ -20,7 +20,7 @@ def configure
     # Configuration parameters
 
     def default_currency
-      Money::Currency.new(Money.default_currency)
+      Money::Currency.new(Money.default_currency) if Money.default_currency
     end
 
     # Set default currency of money library
@@ -35,7 +35,7 @@ def register_currency=(currency_options)
     end
 
     def set_currency_column_for_default_currency!
-      iso_code = default_currency.iso_code
+      iso_code = default_currency && default_currency.iso_code
       currency_column.merge! default: iso_code
     end
 

spec/active_record/monetizable_spec.rb

@@ -949,6 +949,25 @@ class SubProduct < Product
         expect(price.amount).not_to eq(value.amount)
       end
 
+      context 'without a default currency' do
+        let(:product) { OtherProduct.new }
+
+        around do |example|
+          default_currency = Money.default_currency
+          Money.default_currency = nil
+
+          example.run
+
+          Money.default_currency = default_currency
+        end
+
+        it "errors a NoCurrency Error" do
+          expect do
+            product.write_monetized :price, :price_cents, 10.5, false, nil, {}
+          end.to raise_error(Money::Currency::NoCurrency)
+        end
+      end
+
       describe "instance_currency_name" do
         it "updates instance_currency_name attribute" do
           product.write_monetized :sale_price, :sale_price_amount, value, false, :sale_price_currency_code, {}

spec/dummy/app/models/other_product.rb

@@ -0,0 +1,3 @@
+class OtherProduct < ActiveRecord::Base
+  monetize :price_cents
+end

spec/dummy/db/migrate/20240425081448_add_other_products.rb

@@ -0,0 +1,10 @@
+class AddOtherProducts < (Rails::VERSION::MAJOR >= 5 ? ActiveRecord::Migration[4.2] : ActiveRecord::Migration)
+  def change
+    create_table "other_products", force: :cascade do |t|
+      t.string "currency"
+      t.integer "price_cents"
+      t.datetime "created_at"
+      t.datetime "updated_at"
+    end
+  end
+end

spec/dummy/db/structure.sql

@@ -1,5 +1,6 @@
 CREATE TABLE "dummy_products" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "currency" varchar(255), "price_cents" integer, "created_at" datetime NOT NULL, "updated_at" datetime NOT NULL);
 CREATE TABLE "products" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "price_cents" integer, "discount" integer, "created_at" datetime NOT NULL, "updated_at" datetime NOT NULL, "bonus_cents" integer, "optional_price_cents" integer, "sale_price_amount" integer DEFAULT 0 NOT NULL, "sale_price_currency_code" varchar(255), "price_in_a_range_cents" integer);
+CREATE TABLE "other_products" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "price_cents" integer, "currency" varchar(255), "created_at" datetime NOT NULL, "updated_at" datetime NOT NULL;
 CREATE TABLE "schema_migrations" ("version" varchar(255) NOT NULL);
 CREATE TABLE "services" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "charge_cents" integer, "discount_cents" integer, "created_at" datetime NOT NULL, "updated_at" datetime NOT NULL);
 CREATE TABLE "transactions" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "amount_cents" integer, "tax_cents" integer, "currency" varchar(255), "created_at" datetime NOT NULL, "updated_at" datetime NOT NULL);
@@ -18,4 +19,4 @@ INSERT INTO schema_migrations (version) VALUES ('20120607210247');
 
 INSERT INTO schema_migrations (version) VALUES ('20120712202655');
 
-INSERT INTO schema_migrations (version) VALUES ('20130124023419');
+INSERT INTO schema_migrations (version) VALUES ('20130124023419');