be_true matcher from dsl to class

lib/rspec/matchers/base_matcher.rb

@@ -13,7 +13,7 @@ module BaseMatcher
 
       attr_reader :actual, :expected
 
-      def initialize(expected)
+      def initialize(expected=nil)
         @expected = expected
       end
 
@@ -24,6 +24,10 @@ def failure_message_for_should
       def failure_message_for_should_not
         "expected #{actual.inspect} not to #{name_to_sentence}#{expected_to_sentence}"
       end
+
+      def description
+        split_words(name)
+      end
     end
   end
 end

lib/rspec/matchers/be.rb

@@ -2,14 +2,19 @@
 
 module RSpec
   module Matchers
+    class BeTrue
+      include BaseMatcher
 
-    # @method be_true
-    RSpec::Matchers.define :be_true do
-      match do |actual|
+      def matches?(actual)
+        @actual = actual
         actual
       end
     end
 
+    def be_true
+      BeTrue.new
+    end
+
     RSpec::Matchers.define :be_false do
       match do |actual|
         !actual

lib/rspec/matchers/pretty.rb

@@ -6,6 +6,7 @@ def split_words(sym)
       end
 
       def to_sentence(words)
+        return "" unless words
         words = words.map{|w| w.inspect}
         case words.length
           when 0
@@ -42,8 +43,19 @@ def expected_to_sentence
       end
 
       def name
-        defined?(@name) ? @name : self.class.name.split("::").last.downcase
+        defined?(@name) ? @name : underscore(self.class.name.split("::").last)
       end
+
+      # Borrowed from ActiveSupport
+      def underscore(camel_cased_word)
+        word = camel_cased_word.to_s.dup
+        word.gsub!(/([A-Z]+)([A-Z][a-z])/,'\1_\2')
+        word.gsub!(/([a-z\d])([A-Z])/,'\1_\2')
+        word.tr!("-", "_")
+        word.downcase!
+        word
+      end
+
     end
   end
 end