Fix up keyword argument usage in did_you_mean for ruby 1.8

Author: kddnewton

lib/thor/error.rb

@@ -2,6 +2,20 @@ class Thor
   Correctable =
     begin
       require 'did_you_mean'
+
+      module DidYouMean
+        # In order to support versions of Ruby that don't have keyword
+        # arguments, we need our own spell checker class that doesn't take key
+        # words. Even though this code wouldn't be hit because of the check
+        # above, it's still necessary because the interpreter would otherwise be
+        # unable to parse the file.
+        class NoKwargSpellChecker < SpellChecker
+          def initialize(dictionary)
+            @dictionary = dictionary
+          end
+        end
+      end
+
       DidYouMean::Correctable
     rescue LoadError
     end
@@ -29,7 +43,7 @@ def corrections
       end
 
       def spell_checker
-        DidYouMean::SpellChecker.new(dictionary: error.all_commands)
+        DidYouMean::NoKwargSpellChecker.new(error.all_commands)
       end
     end
 
@@ -72,7 +86,7 @@ def corrections
 
       def spell_checker
         @spell_checker ||=
-          DidYouMean::SpellChecker.new(dictionary: error.switches)
+          DidYouMean::NoKwargSpellChecker.new(error.switches)
       end
     end