improve error handling and documentation

bin/annotate

@@ -6,7 +6,7 @@ require 'annotate'
 task = :annotate_models
 
 OptionParser.new do |opts|
-  opts.banner = "Usage: annotate [options]"
+  opts.banner = "Usage: annotate [options] [model_file]*"
 
   opts.on('-d', '--delete', 
   "Remove annotations from all model files") do

lib/annotate/annotate_models.rb

@@ -178,8 +178,15 @@ module AnnotateModels
       models.shift
       models.reject!{|m| m.starts_with?("position=")}
       if models.empty?
-        Dir.chdir(model_dir) do
-          models = Dir["**/*.rb"]
+        begin
+          Dir.chdir(model_dir) do
+            models = Dir["**/*.rb"]
+          end
+        rescue SystemCallError
+          puts "No models found in directory '#{model_dir}'."
+          puts "Either specify models on the command line, or use the --model-dir option."
+          puts "Call 'annotate --help' for more info."
+          exit 1;
         end
       end
       models
@@ -194,7 +201,7 @@ module AnnotateModels
       parts = model.split('::')
       begin
         parts.inject(Object) {|klass, part| klass.const_get(part) }
-      rescue LoadError
+      rescue LoadError, NameError
         Object.const_get(parts.last)
       end
     end
@@ -233,7 +240,8 @@ module AnnotateModels
             end
           end
         rescue Exception => e
-          puts "Unable to annotate #{file}: #{e.message} (#{e.backtrace.first})"
+          puts "Unable to annotate #{file}: #{e.inspect}"
+          puts ""
         end
       end
       if annotated.empty?

lib/tasks/annotate_models.rake

@@ -7,7 +7,7 @@ task :annotate_models => :environment do
   options[:show_indexes] = ENV['show_indexes'] 
   options[:model_dir] = ENV['model_dir']
   options[:include_version] = ENV['include_version']
-  options[:require] = ENV['require'].split(',')
+  options[:require] = ENV['require'] ? ENV['require'].split(',') : nil
   AnnotateModels.do_annotations(options)
 end