Move config_var from Bugzilla and Quote plugin into Plugin class

The config_var tool has been handy for processing configuration
parameters for a plugin.  It seems generic enough to roll into the
Plugin class.

Move the config_var class method and the initialize block into the
Plugin class.  Be sure to call "super" from the subclass's initialize
method.  Move the applicable examples into a separate plugin_spec.

lib/plugin.rb

@@ -53,6 +53,23 @@ def at_time(timestamp, *methods)
           Plugin.registered_times << Event::Time.new(timestamp, self.to_s, method)
         end
       end
+
+      # Declare a plugin configuration parameter with its default value
+      def config_var(name, default)
+        attr_reader name
+        @@config_defaults ||= {}
+        @@config_defaults[self.name] ||= {}
+        @@config_defaults[self.name][name] = default
+      end
+    end
+    def initialize
+      # initialize attr_readers setup with config_var
+      config_prefix = self.class.to_s.underscore
+      (@@config_defaults[self.class.name] || {}).each_pair { |name, default|
+        instance_variable_set("@#{name.to_s}",
+                              bot.config["#{config_prefix}_#{name.to_s}"] ||
+                                default)
+      }
     end
   end
-end
+end

plugins/bugzilla.rb

@@ -25,12 +25,6 @@ class Bugzilla < CampfireBot::Plugin
   on_command 'bug', :describe_command
   # on_message registered below...
 
-  def self.config_var(name, default)
-    attr_reader name
-    @@config_defaults ||= {}
-    @@config_defaults[name] = default
-  end
-
   config_var :data_file, File.join(BOT_ROOT, 'tmp', 'bugzilla.yml')
   config_var :min_period, 30.minutes
   config_var :debug_enabled, false
@@ -45,11 +39,7 @@ def self.config_var(name, default)
     :use_htmlentities, :use_netrc
 
   def initialize()
-    @@config_defaults.each_pair { |name, default|
-      instance_variable_set("@#{name.to_s}",
-                            bot.config["bugzilla_#{name.to_s}"] || default)
-    }
-
+    super
     @bug_id_regexp = Regexp.new(bug_id_pattern, Regexp::IGNORECASE)
     @mention_regexp = Regexp.new(sprintf(mention_pattern,
                                          bug_id_pattern, bug_word_pattern),

plugins/our_quotes.rb

@@ -50,23 +50,14 @@ class OurQuotes < CampfireBot::Plugin
   # Configure with "our_quote_recall_command: quote"
   #on_command 'quote', :quote
 
-  def self.config_var(name, default)
-    attr_reader name
-    @@config_defaults ||= {}
-    @@config_defaults[name] = default
-  end
-
   config_var :data_file, File.join(BOT_ROOT, 'var', 'quote-log.yml')
   config_var :recall_command, "ourquote"
   config_var :debug_enabled, false
 
   attr_reader :use_htmlentities
 
   def initialize()
-    @@config_defaults.each_pair { |name, default|
-      instance_variable_set("@#{name.to_s}",
-                            bot.config["quote_#{name.to_s}"] || default)
-    }
+    super
 
     self.class.on_command recall_command.to_s, :quote
 

spec/bugzilla_spec.rb

@@ -70,23 +70,6 @@
   end
 end
 
-describe "config_var method" do
-  def setup_plugin(klass, config={})
-    @bot = CampfireBot::Bot.instance
-    @bot.stub!(:config).and_return({'nickname' => 'Bot'}.merge(config))
-    @plugin = klass.new
-    CampfireBot::Plugin.registered_plugins[klass.to_s] = @plugin
-  end
-  it "should setup default bug_url value" do
-    setup_plugin Bugzilla
-    @plugin.bug_url.should == "https://bugzilla/show_bug.cgi?id=%s"
-  end
-  it "should allow override of bug_url via bugzilla_bug_url configuration" do
-    setup_plugin Bugzilla, 'bugzilla_bug_url' => 'http://b/%s'
-    @plugin.bug_url.should == "http://b/%s"
-  end
-end
-
 describe "http_fetch_body method" do
   before(:each) do
   end

spec/plugin_spec.rb

@@ -0,0 +1,43 @@
+require 'spec'
+BOT_ROOT        = File.join(File.dirname(__FILE__), '..')
+BOT_ENVIRONMENT = 'test'
+
+require File.join(File.dirname(__FILE__), '../lib/bot.rb')
+bot = CampfireBot::Bot.instance
+
+describe "config_var method" do
+  class ExamplePlugin < CampfireBot::Plugin
+    config_var :foo, "default foo"
+  end
+
+  def setup_plugin(klass, config={})
+    @bot = CampfireBot::Bot.instance
+    @bot.stub!(:config).and_return({'nickname' => 'Bot'}.merge(config))
+    @plugin = klass.new
+    CampfireBot::Plugin.registered_plugins[klass.to_s] = @plugin
+  end
+
+  it "should setup default bug_url value" do
+    setup_plugin ExamplePlugin
+    @plugin.foo.should == "default foo"
+  end
+
+  it "should allow override of parameter via configuration" do
+    setup_plugin ExamplePlugin, 'example_plugin_foo' => 'bar'
+    @plugin.foo.should == "bar"
+  end
+
+  it "should keep defaults for two classes separate" do
+    class ExamplePlugin2 < CampfireBot::Plugin
+      config_var :bar, "default bar"
+    end
+    setup_plugin ExamplePlugin
+    plugin = @plugin
+    setup_plugin ExamplePlugin2
+    plugin.instance_variable_get(:@foo).should == "default foo"
+    @plugin.instance_variable_get(:@bar).should == "default bar"
+    # Used to fail with value "default bar"
+    plugin.instance_variable_get(:@bar).should == nil
+    @plugin.instance_variable_get(:@foo).should == nil
+  end
+end