improved some command code and added more tests

lib/pry/command_set.rb

@@ -160,7 +160,7 @@ class Pry
         instance_exec(*args, &block)
         instance_exec(*args, &prev_block)
       end
-      commands[cmd.name].block = wrapper_block
+      cmd.block = wrapper_block
     end
 
     # Execute a block of code after a command is invoked. The block also
@@ -180,7 +180,7 @@ class Pry
         instance_exec(*args, &prev_block)
         instance_exec(*args, &block)
       end
-      commands[cmd.name].block = wrapper_block
+      cmd.block = wrapper_block
     end
 
     def each &block

test/test_command_set.rb

@@ -142,13 +142,23 @@ describe Pry::CommandSet do
     run.should == true
   end
 
-  it 'should be able to change the descriptions of methods' do
+  it 'should be able to change the descriptions of commands' do
     @set.command('foo', 'bar') {}
     @set.desc 'foo', 'baz'
 
     @set.commands['foo'].description.should == 'baz'
   end
 
+  it 'should get the descriptions of commands' do
+    @set.command('foo', 'bar') {}
+    @set.desc('foo').should == 'bar'
+  end
+
+  it 'should get the descriptions of commands, by listing' do
+    @set.command(/^foo1/, 'bar', :listing => 'foo') {}
+    @set.desc('foo').should == 'bar'
+  end
+
   it 'should return Pry::CommandContext::VOID_VALUE for commands by default' do
     @set.command('foo') { 3 }
     @set.run_command(@ctx, 'foo').should == Pry::CommandContext::VOID_VALUE