Util::Errors class to parse errors from YML and render them via ERB

lib/vagrant/util/errors.rb

@@ -0,0 +1,33 @@
+require 'yaml'
+
+module Vagrant
+  module Util
+    # This class is responsible for outputting errors. It retrieves the errors,
+    # based on their key, from the error file, and then outputs it.
+    class Errors
+      @@errors = nil
+
+      class <<self
+        def reset!
+          @@errors = nil
+        end
+
+        # Returns the hash of errors from the error YML files. This only loads once,
+        # then returns a cached value until {reset!} is called.
+        #
+        # @return [Hash]
+        def errors
+          @@errors ||= YAML.load_file(File.join(PROJECT_ROOT, "templates", "errors.yml"))
+        end
+
+        # Renders the error with the given key and data parameters and returns
+        # the rendered result.
+        #
+        # @return [String]
+        def error_string(key, data = {})
+          TemplateRenderer.render_string(errors[key], data)
+        end
+      end
+    end
+  end
+end

templates/errors.yml

@@ -0,0 +1 @@
+:foo: bar

test/vagrant/util/errors_test.rb

@@ -0,0 +1,52 @@
+require File.join(File.dirname(__FILE__), '..', '..', 'test_helper')
+
+class ErrorsUtilTest < Test::Unit::TestCase
+  include Vagrant::Util
+
+  context "loading the errors from the YML" do
+    setup do
+      YAML.stubs(:load_file)
+      Errors.reset!
+    end
+
+    should "load the file initially, then never again unless reset" do
+      YAML.expects(:load_file).with(File.join(PROJECT_ROOT, "templates", "errors.yml")).once
+      Errors.errors
+      Errors.errors
+      Errors.errors
+      Errors.errors
+    end
+
+    should "reload if reset! is called" do
+      YAML.expects(:load_file).with(File.join(PROJECT_ROOT, "templates", "errors.yml")).twice
+      Errors.errors
+      Errors.reset!
+      Errors.errors
+    end
+  end
+
+  context "getting the error string" do
+    setup do
+      @errors = {}
+      @errors[:foo] = "foo bar baz"
+      Errors.stubs(:errors).returns(@errors)
+    end
+
+    should "render the error string" do
+      TemplateRenderer.expects(:render_string).with(@errors[:foo], anything).once
+      Errors.error_string(:foo)
+    end
+
+    should "pass in any data entries" do
+      data = mock("data")
+      TemplateRenderer.expects(:render_string).with(@errors[:foo], data).once
+      Errors.error_string(:foo, data)
+    end
+
+    should "return the result of the render" do
+      result = mock("result")
+      TemplateRenderer.expects(:render_string).returns(result)
+      assert_equal result, Errors.error_string(:foo)
+    end
+  end
+end