Auto include Dash::IndifferentAccess when Extensions::IndiferentAccess is included in Dash.

5 files changed, 29 insertions, 2 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f1b1892..b8b0e8d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 **Note:** This version introduces several backward incompatible API changes. See [UPGRADING](UPGRADING.md) for details.
 
 * [#172](https://github.com/intridea/hashie/pull/172): Added Dash and Trash#update_attributes! - [@gregory](https://github.com/gregory).
+* [#173](https://github.com/intridea/hashie/pull/173): Auto include Dash::IndifferentAccess when Extensions::IndiferentAccess is included in Dash - [@gregory](https://github.com/gregory).
 * [#169](https://github.com/intridea/hashie/pull/169): Hash#to_hash will also convert nested objects that implement to_hash - [@gregory](https://github.com/gregory).
 * [#150](https://github.com/intridea/hashie/pull/159): Handle nil intermediate object on deep fetch - [@stephenaument](https://github.com/stephenaument).
 * [#146](https://github.com/intridea/hashie/issues/146): Mash#respond_to? inconsistent with #method_missing and does not respond to #permitted? - [@dblock](https://github.com/dblock).
diff --git a/README.md b/README.md
index d6146b1..242c2f8 100644
--- a/README.md
+++ b/README.md
@@ -81,8 +81,6 @@ This extension can be mixed in to instantly give you indifferent access to your
 
 A unique feature of Hashie's IndifferentAccess mixin is that it will inject itself recursively into subhashes *without* reinitializing the hash in question. This means you can safely merge together indifferent and non-indifferent hashes arbitrarily deeply without worrying about whether you'll be able to `hash[:other][:another]` properly.
 
-Use `Hashie::Extensions::Dash::IndifferentAccess` for instances of `Hashie::Dash`.
-
 ### IgnoreUndeclared
 
 This extension can be mixed in to silently ignore undeclared properties on initialization instead of raising an error. This is useful when using a Trash to capture a subset of a larger hash.
diff --git a/lib/hashie/extensions/indifferent_access.rb b/lib/hashie/extensions/indifferent_access.rb
index 8af278e..4fc5bb7 100644
--- a/lib/hashie/extensions/indifferent_access.rb
+++ b/lib/hashie/extensions/indifferent_access.rb
@@ -24,6 +24,10 @@ module Hashie
     #
     module IndifferentAccess
       def self.included(base)
+        Hashie::Extensions::Dash::IndifferentAccess::ClassMethods.tap do |extension|
+          base.extend(extension) if base <= Hashie::Dash && !base.singleton_class.included_modules.include?(extension)
+        end
+
         base.class_eval do
           alias_method :regular_writer, :[]=
           alias_method :[]=, :indifferent_writer
diff --git a/spec/hashie/extensions/dash/indifferent_access_spec.rb b/spec/hashie/extensions/dash/indifferent_access_spec.rb
index 80d300c..f88a280 100644
--- a/spec/hashie/extensions/dash/indifferent_access_spec.rb
+++ b/spec/hashie/extensions/dash/indifferent_access_spec.rb
@@ -6,6 +6,16 @@ describe Hashie::Extensions::Dash::IndifferentAccess do
     property :name
   end
 
+  context 'when included in Dash' do
+    let(:patch) { Hashie::Extensions::Dash::IndifferentAccess::ClassMethods }
+    let(:dash_class) { Class.new(Hashie::Dash) }
+
+    it 'extends with the patch once' do
+      expect(patch).to receive(:extended).with(dash_class).once
+      dash_class.send(:include, Hashie::Extensions::Dash::IndifferentAccess)
+    end
+  end
+
   context 'initialized with' do
     it 'string' do
       instance = DashWithIndifferentAccess.new('name' => 'Name')
diff --git a/spec/hashie/extensions/indifferent_access_spec.rb b/spec/hashie/extensions/indifferent_access_spec.rb
index 8ae982d..225a236 100644
--- a/spec/hashie/extensions/indifferent_access_spec.rb
+++ b/spec/hashie/extensions/indifferent_access_spec.rb
@@ -26,6 +26,20 @@ describe Hashie::Extensions::IndifferentAccess do
     end
   end
 
+  class IndifferentHashWithDash < Hashie::Dash
+    include Hashie::Extensions::IndifferentAccess
+    property :foo
+  end
+
+  describe 'when included in dash' do
+    let(:params) { { foo: 'bar' } }
+    subject { IndifferentHashWithDash.new(params) }
+
+    it 'initialize with a symbol' do
+      expect(subject.foo).to eq params[:foo]
+    end
+  end
+
   shared_examples_for 'hash with indifferent access' do
     it 'is able to access via string or symbol' do
       h = subject.build(abc: 123)