Improved error reporting especially around never shallowing exceptions. Debugging helpers should be much easier now #980 [Nicholas Seckar]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@985 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activesupport/CHANGELOG

@@ -1,3 +1,14 @@
+*SVN*
+
+* Added Object#suppress which allows you to make a saner choice around with exceptions to swallow #980. Example:
+
+    suppress(ZeroDivisionError) { 1/0 }
+  
+  ...instead of:
+  
+    1/0 rescue nil # BAD, EVIL, DIRTY.
+
+
 *1.0.2*
 
 * Added Kernel#returning -- a Ruby-ized realization of the K combinator, courtesy of Mikael Brockman.

activesupport/lib/active_support/core_ext/load_error.rb

@@ -0,0 +1,34 @@
+class MissingSourceFile < LoadError
+  attr_reader :path
+  def initialize(message, path)
+    super(message)
+    @path = path
+  end
+  
+  def self.from_message(message)
+    REGEXPS.each do |regexp, capture|
+      match = regexp.match(message)
+      return MissingSourceFile.new(message, match[capture]) unless match.nil?
+    end
+    nil
+  end
+  
+  REGEXPS = [
+    [/^no such file to load -- (.+)$/i, 1],
+    [/^Missing \w+ (file\s*)?([^\s]+.rb)$/i, 2],
+    [/^Missing API definition file in (.+)$/i, 1]
+  ]
+end
+
+module ActiveSupport
+  module CoreExtensions
+    module LoadErrorExtensions
+      module LoadErrorClassMethods
+        def new(*args)
+          (self == LoadError && MissingSourceFile.from_message(args.first)) || super
+        end
+      end
+      ::LoadError.extend(LoadErrorClassMethods)
+    end
+  end
+end

activesupport/test/core_ext/load_error_tests.rb

@@ -0,0 +1,17 @@
+require 'test/unit'
+require File.dirname(__FILE__) + '/../../lib/active_support/core_ext/load_error'
+
+class TestMissingSourceFile < Test::Unit::TestCase
+  def test_with_require
+    assert_raises(MissingSourceFile) { require 'no_this_file_don\'t_exist' }
+  end
+  def test_with_load
+    assert_raises(MissingSourceFile) { load 'nor_does_this_one' }
+  end
+  def test_path
+    begin load 'nor/this/one.rb'
+    rescue MissingSourceFile => e
+      assert_equal 'nor/this/one.rb', e.path
+    end
+  end
+end