Added more informative exception when using helper :some_helper and the helper...

Added more informative exception when using helper :some_helper and the helper requires another file that fails, you'll get an error message tells you what file actually failed to load, rather than falling back on assuming it was the helper file itself #346 [dblack]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@250 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

 *SVN*
 
+* Added more informative exception when using helper :some_helper and the helper requires another file that fails, you'll get an
+  error message tells you what file actually failed to load, rather than falling back on assuming it was the helper file itself #346 [dblack]
+
 * Fixed regression with Base#reset_session that wouldn't use the the DEFAULT_SESSION_OPTIONS [adam@the-kramers.net]
 
 * Fixed error rendering of rxml documents to not just swallow the exception and return 0 (still not guessing the right line, but hey)

actionpack/lib/action_controller/helpers.rb

@@ -55,8 +55,13 @@ def helper(*args, &block)
             class_name = Inflector.camelize(file_name)
             begin
               require_dependency(file_name)
-            rescue LoadError
-              raise LoadError, "Missing helper file helpers/#{file_name}.rb"
+            rescue LoadError => load_error
+              requiree = / -- (.*?)(\.rb)?$/.match(load_error).to_a[1]
+              if requiree == file_name
+                raise LoadError, "Missing helper file helpers/#{file_name}.rb"
+              else
+                raise LoadError, "Can't load file: #{requiree}"
+              end
             end
             raise ArgumentError, "Missing #{class_name} module in helpers/#{file_name}.rb" unless Object.const_defined?(class_name)
             add_template_helper(Object.const_get(class_name))

actionpack/test/controller/helper_test.rb

@@ -70,6 +70,12 @@ def test_declare_missing_helper
     assert_raise(LoadError) { @controller_class.helper :missing }
   end
 
+  def test_declare_missing_file_from_helper
+    require 'broken_helper'
+    rescue LoadError => e
+      assert_nil /\bbroken_helper\b/.match(e.to_s)[1]
+  end
+
   def test_helper_block
     assert_nothing_raised {
       @controller_class.helper { def block_helper_method; end }
@@ -107,4 +113,4 @@ def test_helper=(helper_module)
       self.class.const_set('TestHelper', helper_module)
       $VERBOSE = old_verbose
     end
-end
\ No newline at end of file
+end