Add options for show indexes in annotations

bin/annotate

@@ -12,6 +12,7 @@ OptionParser.new do |opts|
   opts.on('-r', '--routes') { task = :annotate_routes }
   opts.on('-v', '--version') { puts "Annotate v#{Annotate::VERSION}"; exit }
   opts.on('-m', '--show-migration') { ENV['include_version'] = "yes" }
+  opts.on('-i', '--show-indexes') { ENV['show_indexes'] = "yes" }
 end.parse!
 
 begin

lib/annotate/annotate_models.rb

@@ -32,7 +32,7 @@ module AnnotateModels
     # to create a comment block containing a line for
     # each column. The line contains the column name,
     # the type (and length), and any optional attributes
-    def get_schema_info(klass, header)
+    def get_schema_info(klass, header, options = {})
       info = "# #{header}\n#\n"
       info << "# Table name: #{klass.table_name}\n#\n"
 
@@ -59,9 +59,26 @@ module AnnotateModels
         info << sprintf("#  %-#{max_size}.#{max_size}s:%-15.15s %s", col.name, col_type, attrs.join(", ")).rstrip + "\n"
       end
 
+      if options[:show_indexes]
+        info << get_index_info(klass)
+      end
+
       info << "#\n\n"
     end
 
+    def get_index_info(klass)
+      index_info = "#\n# Indexes\n#\n"
+
+      indexes = klass.connection.indexes(klass.table_name)
+      return "" if indexes.empty?
+
+      max_size = indexes.collect{|index| index.name.size}.max + 1
+      indexes.each do |index|
+        index_info << sprintf("#  %-#{max_size}.#{max_size}s %s %s", index.name, "(#{index.columns.join(",")})", index.unique ? "UNIQUE" : "").rstrip + "\n"
+      end
+      return index_info
+    end
+
     # Add a schema block to a file. If the file already contains
     # a schema info block (a comment starting with "== Schema Information"), check if it
     # matches the block that is already there. If so, leave it be. If not, remove the old
@@ -116,7 +133,7 @@ module AnnotateModels
     # files were modified.
 
     def annotate(klass, file, header,options={})
-      info = get_schema_info(klass, header)
+      info = get_schema_info(klass, header, options)
       annotated = false
       model_name = klass.name.underscore
       model_file_name = File.join(MODEL_DIR, file)

lib/tasks/annotate_models.rake

@@ -4,6 +4,7 @@ task :annotate_models => :environment do
   options={}
   options[:position_in_class] = ENV['position_in_class'] || ENV['position'] || :before
   options[:position_in_fixture] = ENV['position_in_fixture'] || ENV['position']  || :before
+  options[:show_indexes] = ENV['show_indexes'] 
   AnnotateModels.do_annotations(options)
 end