add name class attribute for user defined handlers. more readable invalid event handler exception name.

5 files changed, 70 insertions, 18 deletions

diff --git a/lib/chef/chef_class.rb b/lib/chef/chef_class.rb
index c490615861..d9c141b85d 100644
--- a/lib/chef/chef_class.rb
+++ b/lib/chef/chef_class.rb
@@ -51,8 +51,10 @@ class Chef
     attr_reader :run_context
 
     # Register an event handler with user specified block
+    #
+    # @return[Chef::EventDispatch::Base] handler object
     def event_handler(&block)
-      dsl = Chef::EventDispatch::DSL.new
+      dsl = Chef::EventDispatch::DSL.new('Chef client DSL')
       dsl.instance_eval(&block)
     end
 
diff --git a/lib/chef/event_dispatch/dsl.rb b/lib/chef/event_dispatch/dsl.rb
index e700fd1640..98854a4716 100644
--- a/lib/chef/event_dispatch/dsl.rb
+++ b/lib/chef/event_dispatch/dsl.rb
@@ -22,32 +22,43 @@ require 'chef/config'
 class Chef
   module EventDispatch
     class DSL
+      attr_reader :handler
+
+      def initialize(name)
+        klass = Class.new(Chef::EventDispatch::Base) do
+          def self.name
+            @@name
+          end
+        end
+        klass.class_variable_set(:@@name, name)
+        @handler = klass.new
+        # Use current event.register API to add anonymous handler if
+        # run_context and associated event dispatcher is set, else fallback to
+        # Chef::Config[:hanlder].
+        if Chef.run_context && Chef.run_context.events
+          Chef::Log.debug("Registering handler '#{name}' using events api")
+          Chef.run_context.events.register(handler)
+        else
+          Chef::Log.debug("Registering handler '#{name}' using global config")
+          Chef::Config[:event_handlers] << handler
+        end
+      end
+
       # Adds a new event handler derived from base handler
       # with user defined block against a chef event
       #
       # @return [Chef::EventDispatch::Base] a base handler object
       def on(event_type, &block)
         validate!(event_type)
-        handler = Chef::EventDispatch::Base.new
         handler.define_singleton_method(event_type) do |*args|
-          block.call(args)
-        end
-        # Use current event dispatch system is run_context and associated event
-        # dispatcher is set else fall back to Chef::Config[:hanlder]
-        if Chef.run_context && Chef.run_context.events
-          Chef::Log.debug('Registering handler using run_context')
-          Chef.run_context.events.register(handler)
-        else
-          Chef::Log.debug('Registering handler using config, this will only work inside config file')
-          Chef::Config[:event_handlers] << handler
+          instance_exec(*args, &block)
         end
-        handler
       end
 
       private
       def validate!(event_type)
         all_event_types = (Chef::EventDispatch::Base.instance_methods - Object.instance_methods)
-        raise Chef::Exceptions::UnknownEventType unless all_event_types.include?(event_type)
+        raise Chef::Exceptions::InvalidEventType, "Invalid event type: #{event_type}" unless all_event_types.include?(event_type)
       end
     end
   end
diff --git a/lib/chef/exceptions.rb b/lib/chef/exceptions.rb
index f38bc32571..0857a9e75e 100644
--- a/lib/chef/exceptions.rb
+++ b/lib/chef/exceptions.rb
@@ -98,7 +98,7 @@ class Chef
     class InvalidResourceReference < RuntimeError; end
     class ResourceNotFound < RuntimeError; end
     class VerificationNotFound < RuntimeError; end
-    class UnknownEventType < ArgumentError; end
+    class InvalidEventType < ArgumentError; end
 
     # Can't find a Resource of this type that is valid on this platform.
     class NoSuchResourceType < NameError
diff --git a/spec/unit/chef_class_spec.rb b/spec/unit/chef_class_spec.rb
index 65a637dcbb..d6bf74572e 100644
--- a/spec/unit/chef_class_spec.rb
+++ b/spec/unit/chef_class_spec.rb
@@ -108,7 +108,7 @@ describe "Chef class" do
           on :yolo do
           end
         end
-      end.to raise_error(Chef::Exceptions::UnknownEventType)
+      end.to raise_error(Chef::Exceptions::InvalidEventType)
     end
   end
 end
diff --git a/spec/unit/event_dispatch/dsl_spec.rb b/spec/unit/event_dispatch/dsl_spec.rb
index ba91dde2e7..e30b1cb40e 100644
--- a/spec/unit/event_dispatch/dsl_spec.rb
+++ b/spec/unit/event_dispatch/dsl_spec.rb
@@ -20,16 +20,55 @@ require 'spec_helper'
 require 'chef/event_dispatch/dsl'
 
 describe Chef::EventDispatch::DSL do
-  subject{ described_class.new }
+  subject{ described_class.new('test') }
 
   it 'raise error when invalid event type is supplied' do
     expect do
       subject.on(:foo_bar) {}
-    end.to raise_error(Chef::Exceptions::UnknownEventType)
+    end.to raise_error(Chef::Exceptions::InvalidEventType)
   end
 
   it 'register user hooks against valid event type' do
     subject.on(:run_failed) {'testhook'}
     expect(Chef::Config[:event_handlers].first.run_failed).to eq('testhook')
   end
+
+  it 'preserve state across event hooks' do
+    Chef::Config.reset!
+    node = Chef::Node.new
+    calls = []
+    Chef.event_handler do
+      on :resource_updated do
+        calls << :updated
+      end
+      on :resource_action_start do
+        calls << :started
+      end
+    end
+    events = Chef::EventDispatch::Dispatcher.new(*Chef::Config[:event_handlers])
+    rc = Chef::RunContext.new(node, nil, events)
+    resource = Chef::Resource::RubyBlock.new('foo', rc)
+    resource.block { }
+    resource.run_action(:run)
+    expect(calls).to eq([:started, :updated])
+  end
+
+  it 'preserve instance variables across handler callbacks' do
+    Chef::Config.reset!
+    node = Chef::Node.new
+    Chef.event_handler do
+      on :resource_action_start do
+        @ivar = [1]
+      end
+      on :resource_updated do
+        @ivar << 2
+      end
+    end
+    events = Chef::EventDispatch::Dispatcher.new(*Chef::Config[:event_handlers])
+    rc = Chef::RunContext.new(node, nil, events)
+    resource = Chef::Resource::RubyBlock.new('foo', rc)
+    resource.block { }
+    resource.run_action(:run)
+    expect(Chef::Config[:event_handlers].first.instance_variable_get(:@ivar)).to eq([1, 2])
+  end
 end