String.undent for prettier HEREDOCs

Library/Homebrew/extend/ARGV.rb

@@ -61,8 +61,7 @@ module HomebrewArgvExtension
     return false
   end
 
-  def usage
+  def usage; <<-EOS.undent
-    <<-EOS
     Usage: brew command [formula] ...
     Usage: brew [--prefix] [--cache] [--version|-v]
     Usage: brew [--verbose|-v]

Library/Homebrew/extend/string.rb

@@ -0,0 +1,15 @@
+class String
+  def undent
+    gsub /^.{#{slice(/^ +/).length}}/, ''
+  end
+end
+
+if __FILE__ == $0
+  undented = <<-EOS.undent
+    hi
+....my friend over
+    there
+  EOS
+  
+  assert undented == "hi\nmy friend over\nthere\n"
+end

Library/Homebrew/global.rb

@@ -1,5 +1,6 @@
 require 'extend/pathname'
 require 'extend/ARGV'
+require 'extend/string'
 require 'utils'
 
 ARGV.extend(HomebrewArgvExtension)