Fix #8: undefined method strip!' for nil:NilClass on nil message.

CHANGELOG.md

@@ -1,5 +1,6 @@
 ### 0.3.1 (Next)
 
+* [#8](https://github.com/dblock/slack-ruby-bot/issues/8): Fix: `undefined method `strip!' for nil:NilClass` on nil message - [@dblock](https://github.com/dblock).
 * Your contribution here.
 
 ### 0.3.0 (7/19/2015)

lib/slack-ruby-bot/hooks/message.rb

@@ -5,7 +5,7 @@ module Message
 
       def message(data)
         data = Hashie::Mash.new(data)
-        data.text.strip!
+        data.text.strip! if data.text
         result = child_command_classes.detect { |d| d.invoke(data) }
         result ||= built_in_command_classes.detect { |d| d.invoke(data) }
         result ||= SlackRubyBot::Commands::Unknown.tap { |d| d.invoke(data) }

spec/slack-ruby-bot/commands/nil_message_spec.rb

@@ -0,0 +1,21 @@
+require 'spec_helper'
+
+describe SlackRubyBot::Commands do
+  let! :command do
+    Class.new(SlackRubyBot::Commands::Base) do
+      command 'nil_text'
+
+      def self.call(data, _match)
+        send_message data.channel, nil
+      end
+    end
+  end
+  def app
+    SlackRubyBot::App.new
+  end
+  it 'ignores nil messages' do
+    allow(Giphy).to receive(:random)
+    expect(SlackRubyBot::Commands::Base).to_not receive(:send_message_with_gif)
+    app.send(:message, text: nil, channel: 'channel', user: 'user')
+  end
+end