Make debugger statements _just work_

- debugger statements work anywhere in the code, even parts that are
  outside RSpec's control (like before a describe declaration).
- deprecated --debug/-d command line option
  - it doesn't do anything any more
- warns if ruby-debug is not installed
- only downside is for people who like to leave debugger statements
  around in their code

History.markdown

@@ -4,9 +4,14 @@
 
 [full changelog](http://github.com/rspec/rspec-core/compare/v2.1.0...master)
 
+* Deprecations
+  * --debug/-d on command line is deprecated and now has no effect
+
 * Enhancements
   * Raise exception with helpful message when rspec-1 is loaded alongside
     rspec-2 (Justin Ko)
+  * debugger statements _just work_ as long as ruby-debug is installed
+    * otherwise you get warned, but not fired
 
 * Bug fixes
   * Make sure --fail-fast makes it across drb

Upgrade.markdown

@@ -1,4 +1,16 @@
-# New features in rspec-core-2.1
+# rspec-core-2.2
+
+## Command line
+
+### --debug/-d is now deprecated
+
+This command line option is now has no effect (other than a deprecation
+warning). To use the debugger, just add a `debugger` statement anywhere in your
+code. As long as you have ruby-debug installed, it will just work. If you
+don't, then you'll get a friendly warning telling you what's going on, but
+execution will continue.
+
+# rspec-core-2.1
 
 ## Command line
 
@@ -61,7 +73,7 @@ JRuby installation to a newer release that allows the example to pass, RSpec
 will report it as a failure (`Expected pending '...' to fail.  No Error was raised.`),
 so that know that you can remove the call to `pending`.
 
-# New features in rspec-core-2.0
+# rspec-core-2.0
 
 ### Runner
 

lib/rspec/core/configuration.rb

@@ -182,21 +182,11 @@ def requires=(paths)
       end
 
       def debug=(bool)
-        return unless bool
-        begin
-          require 'ruby-debug'
-        rescue LoadError
-          raise <<-EOM
-
-#{'*'*50}
-You must install ruby-debug to run rspec with the --debug option.
-
-If you have ruby-debug installed as a ruby gem, then you need to either
-require 'rubygems' or configure the RUBYOPT environment variable with
-the value 'rubygems'.
-#{'*'*50}
-EOM
-        end
+        RSpec.warn_deprecation <<-WARNING
+The debug option (config.debug = true or --debug/-d on the command line)
+is deprecated and no longer has any effect. This message will be removed
+from future versions of RSpec.
+WARNING
       end
 
       def line_number=(line_number)

lib/rspec/core/extensions/kernel.rb

@@ -1,5 +1,22 @@
 module Kernel
-  def debugger(*args)
-    RSpec.configuration.error_stream.puts "debugger statement ignored, use -d or --debug option to enable debugging\n#{caller(0)[1]}"
-  end unless respond_to?(:debugger)
+  def method_missing(m, *a)
+    if m.to_s == 'debugger'
+      begin
+        require 'ruby-debug'
+        debugger
+      rescue LoadError => e
+        warn <<-EOM
+#{'*'*50}
+The debugger statement on the following line was ignored:
+
+  #{caller(0).detect {|l| l !~ /method_missing/}}
+ 
+To use the debugger statement, you must install ruby-debug.
+#{'*'*50}
+EOM
+      end
+    else
+      super
+    end
+  end
 end

spec/rspec/core/configuration_spec.rb

@@ -531,20 +531,13 @@ def that_thing
       end
     end
 
-    describe "#debug=true" do
-      it "requires 'ruby-debug'" do
-        config.should_receive(:require).with('ruby-debug')
+    describe "#debug=" do
+      it "is deprecated" do
+        RSpec.should_receive(:warn_deprecation)
         config.debug = true
       end
     end
 
-    describe "#debug=false" do
-      it "does not require 'ruby-debug'" do
-        config.should_not_receive(:require).with('ruby-debug')
-        config.debug = false
-      end
-    end
-
     describe "#output=" do
       it "sets the output" do
         output = mock("output")

spec/rspec/core/kernel_extensions_spec.rb

@@ -1,9 +1,12 @@
 require 'spec_helper'
 
 describe "extensions" do
-  describe "debugger" do
-    it "is defined on Kernel" do
-      Kernel.should respond_to(:debugger)
+  describe "#debugger" do
+    it "warns if ruby-debug is not installed" do
+      object = Object.new
+      object.should_receive(:warn).with(/debugger .* ignored/)
+      object.stub(:require) { raise LoadError }
+      object.method_missing(:debugger)
     end
   end
 end