add using to kernel.

3 files changed, 36 insertions, 0 deletions

diff --git a/lib/nasty.rb b/lib/nasty.rb
index acfdce1..842f05b 100644
--- a/lib/nasty.rb
+++ b/lib/nasty.rb
@@ -1,5 +1,6 @@
 require "nasty/command"
 require "nasty/composite_command"
+require "nasty/kernel"
 require "nasty/version"
 
 module Nasty
diff --git a/lib/nasty/kernel.rb b/lib/nasty/kernel.rb
new file mode 100644
index 0000000..d858e56
--- /dev/null
+++ b/lib/nasty/kernel.rb
@@ -0,0 +1,9 @@
+module Kernel
+  def using(resource, &block)
+    begin
+      block.call
+    ensure
+      resource.dispose
+    end
+  end
+end
diff --git a/spec/unit/using_spec.rb b/spec/unit/using_spec.rb
new file mode 100644
index 0000000..8988fcb
--- /dev/null
+++ b/spec/unit/using_spec.rb
@@ -0,0 +1,26 @@
+require "spec_helper"
+
+describe "using" do
+  let(:item) { double("item", dispose: true) }
+
+  it "disposes the item" do
+    using(item) { }
+    item.should have_received(:dispose)
+  end
+
+  it "performs the action" do
+    ran = false
+    using(item) do
+      ran = true
+    end
+    ran.should be_true
+  end
+
+  it "always cleans up the resource" do
+    begin
+      using(item) { raise "heck" }
+    rescue
+    end
+    item.should have_received(:dispose)
+  end
+end