Refactor VagrantError to be more flexible so not as many subclasses will be needed

lib/vagrant/errors.rb

@@ -9,7 +9,6 @@ module Vagrant
     # error code, and the error key is used as a default message from
     # I18n.
     class VagrantError < StandardError
-      DEFAULT_NAMESPACE = "vagrant.errors"
       @@used_codes = []
 
       def self.status_code(code = nil)
@@ -23,19 +22,34 @@ module Vagrant
 
       def self.error_key(key=nil, namespace=nil)
         define_method(:error_key) { key }
-        define_method(:error_namespace) { namespace } if namespace
+        error_namespace(namespace) if namespace
+      end
+
+      def self.error_namespace(namespace)
+        define_method(:error_namespace) { namespace }
       end
 
       def initialize(message=nil, *args)
-        message = translate_error(error_key, message) if respond_to?(:error_key)
+        message = { :_key => message } if message && !message.is_a?(Hash)
+        message = { :_key => error_key, :_namespace => error_namespace }.merge(message || {})
+        message = translate_error(message)
+
         super
       end
 
+      # The default error namespace which is used for the error key.
+      # This can be overridden here or by calling the "error_namespace"
+      # class method.
+      def error_namespace; "vagrant.errors"; end
+
+      # The key for the error message. This should be set using the
+      # {error_key} method but can be overridden here if needed.
+      def error_key; ""; end
+
       protected
 
-      def translate_error(key, opts=nil)
-        namespace = respond_to?(:error_namespace) ? error_namespace : DEFAULT_NAMESPACE
-        I18n.t("#{namespace}.#{key}", opts)
+      def translate_error(opts)
+        I18n.t("#{opts[:_namespace]}.#{opts[:_key]}", opts)
       end
     end
 

test/locales/en.yml

@@ -1,5 +1,8 @@
 en:
   vagrant:
-    errors:
-      test_key: This is a test key
-      test_key_with_interpolation: This is a test key that says %{key}
+    test:
+      errors:
+        test_key: This is a test key
+        test_key_with_interpolation: This is a test key that says %{key}
+      alternate:
+        test_key: This is an alternate

test/vagrant/errors_test.rb

@@ -2,7 +2,8 @@ require "test_helper"
 
 class ErrorsTest < Test::Unit::TestCase
   setup do
-    @super = Vagrant::Errors::VagrantError
+    @klass = Vagrant::Errors::VagrantError
+    @super = Class.new(@klass) { error_namespace("vagrant.test.errors") }
   end
 
   should "set the given status code" do
@@ -12,23 +13,30 @@ class ErrorsTest < Test::Unit::TestCase
 
   should "raise an error if attempting to set the same status code twice" do
     klass = Class.new(@super) { status_code(4445) }
+
     assert_raises(RuntimeError) {
       Class.new(@super) { status_code(4445) }
     }
   end
 
-  should "use the given message if no set error key" do
+  should "translate the given message if non-hash is given" do
     klass = Class.new(@super)
-    assert_equal "foo", klass.new("foo").message
+    assert_equal I18n.t("vagrant.test.errors.test_key"), klass.new("test_key").message
+  end
+
+  should "use the alternate namespace if given" do
+    klass = Class.new(@super)
+    instance = klass.new(:_key => :test_key, :_namespace => "vagrant.test.alternate")
+    assert_equal I18n.t("vagrant.test.alternate.test_key"), instance.message
   end
 
   should "use the translation from I18n if specified" do
     klass = Class.new(@super) { error_key(:test_key) }
-    assert_equal I18n.t("vagrant.errors.test_key"), klass.new.message
+    assert_equal I18n.t("vagrant.test.errors.test_key"), klass.new.message
   end
 
   should "use the translation with the options specified if key given" do
     klass = Class.new(@super) { error_key(:test_key_with_interpolation) }
-    assert_equal I18n.t("vagrant.errors.test_key_with_interpolation", :key => "yo"), klass.new(:key => "yo").message
+    assert_equal I18n.t("vagrant.test.errors.test_key_with_interpolation", :key => "yo"), klass.new(:key => "yo").message
   end
 end