Add missing String methods to make all specs pass with Ruby 1.8.6

spec/spec_helper.rb

@@ -17,6 +17,35 @@ def stub_dotfile!
   File.should_receive(:readable?).at_least(:once).with(dotfile).and_return(false)
 end
 
-# Infinity Test runs tests as subprocesses, which sets STDOUT.tty? to false and 
-# would otherwise prematurely disallow colors. We'll test the defaults later.
+# The following is needed for the Infinity Test. It runs tests as subprocesses,
+# which sets STDOUT.tty? to false and would otherwise prematurely disallow colors.
 AwesomePrint.force_colors!
+
+# Ruby 1.8.6 only: define missing String methods that are needed for the specs to pass.
+if RUBY_VERSION < '1.8.7'
+  class String
+    def shellescape # Taken from Ruby 1.9.2 standard library, see lib/shellwords.rb.
+      return "''" if self.empty?
+      str = self.dup
+      str.gsub!(/([^A-Za-z0-9_\-.,:\/@\n])/n, "\\\\\\1")
+      str.gsub!(/\n/, "'\n'")
+      str
+    end
+
+    def start_with?(*prefixes)
+      prefixes.each do |prefix|
+        prefix = prefix.to_s
+        return true if prefix == self[0, prefix.size]
+      end
+      false
+    end
+
+    def end_with?(*suffixes)
+      suffixes.each do |suffix|
+        suffix = suffix.to_s
+        return true if suffix == self[-suffix.size, suffix.size]
+      end
+      false
+    end
+  end
+end