Add automatic key formatting. (#15)

lib/jsonapi/deserializable/resource.rb

@@ -10,12 +10,14 @@ module JSONAPI
         attr_accessor :type_block, :id_block, :attr_blocks,
                       :has_one_rel_blocks, :has_many_rel_blocks,
                       :default_attr_block, :default_has_one_rel_block,
-                      :default_has_many_rel_block
+                      :default_has_many_rel_block,
+                      :key_formatter
       end
 
       self.attr_blocks         = {}
       self.has_one_rel_blocks  = {}
       self.has_many_rel_blocks = {}
+      self.key_formatter       = proc { |k| k }
 
       def self.inherited(klass)
         super
@@ -27,6 +29,7 @@ module JSONAPI
         klass.default_attr_block  = default_attr_block
         klass.default_has_one_rel_block   = default_has_one_rel_block
         klass.default_has_many_rel_block  = default_has_many_rel_block
+        klass.key_formatter = key_formatter
       end
 
       def self.call(payload)
@@ -95,7 +98,7 @@ module JSONAPI
         block = self.class.attr_blocks[key] || self.class.default_attr_block
         return {} unless block
 
-        hash = block.call(val, key)
+        hash = block.call(val, self.class.key_formatter.call(key))
         register_mappings(hash.keys, "/data/attributes/#{key}")
         hash
       end
@@ -122,7 +125,7 @@ module JSONAPI
 
         id   = val['data'] && val['data']['id']
         type = val['data'] && val['data']['type']
-        hash = block.call(val, id, type, key)
+        hash = block.call(val, id, type, self.class.key_formatter.call(key))
         register_mappings(hash.keys, "/data/relationships/#{key}")
         hash
       end
@@ -136,7 +139,7 @@ module JSONAPI
 
         ids   = val['data'].map { |ri| ri['id'] }
         types = val['data'].map { |ri| ri['type'] }
-        hash = block.call(val, ids, types, key)
+        hash = block.call(val, ids, types, self.class.key_formatter.call(key))
         register_mappings(hash.keys, "/data/relationships/#{key}")
         hash
       end

lib/jsonapi/deserializable/resource/dsl.rb

@@ -47,6 +47,10 @@ module JSONAPI
             self.default_has_many_rel_block = block || DEFAULT_HAS_MANY_BLOCK
           end
         end
+
+        def key_format(callable = nil, &block)
+          self.key_formatter = callable || block
+        end
       end
     end
   end

spec/resource/DSL/key_format_spec.rb

@@ -0,0 +1,96 @@
+require 'spec_helper'
+
+describe JSONAPI::Deserializable::Resource, '.key_format' do
+  subject { klass.call(payload) }
+
+  let(:payload) do
+    {
+      'data' => {
+        'type' => 'foo',
+        'attributes' => { 'foo' => 'bar', 'foo-bar' => 'baz' },
+        'relationships' => {
+          'baz' => {
+            'data' => nil
+          },
+          'bar-baz' => {
+            'data' => []
+          }
+        }
+      }
+    }
+  end
+
+  context 'when all fields are whitelisted' do
+    context 'when a key formatter is provided as a block' do
+      let(:klass) do
+        Class.new(JSONAPI::Deserializable::Resource) do
+          key_format { |k| k.capitalize }
+          attributes
+          has_many
+          has_one
+        end
+      end
+
+      it 'formats keys accordingly' do
+        is_expected.to eq(Foo: 'bar', 'Foo-bar'.to_sym => 'baz',
+                          Baz_id: nil, Baz_type: nil,
+                          'Bar-baz_ids'.to_sym => [],
+                          'Bar-baz_types'.to_sym => [])
+      end
+    end
+
+    context 'when a key formatter is provided as a callable' do
+      let(:klass) do
+        Class.new(JSONAPI::Deserializable::Resource) do
+          key_format ->(k) { k.capitalize }
+          attributes
+          has_many
+          has_one
+        end
+      end
+
+      it 'formats keys accordingly' do
+        is_expected.to eq(Foo: 'bar', 'Foo-bar'.to_sym => 'baz',
+                          Baz_id: nil, Baz_type: nil,
+                          'Bar-baz_ids'.to_sym => [],
+                          'Bar-baz_types'.to_sym => [])
+      end
+    end
+  end
+
+  context 'when certain fields are whitelisted' do
+    let(:klass) do
+      Class.new(JSONAPI::Deserializable::Resource) do
+        key_format { |k| k.capitalize }
+        attributes :foo
+        has_one :baz
+      end
+    end
+
+    it 'formats keys accordingly' do
+      is_expected.to eq(Foo: 'bar',
+                        Baz_id: nil, Baz_type: nil)
+    end
+  end
+
+  context 'when inheriting' do
+    let(:klass) do
+      superclass = Class.new(JSONAPI::Deserializable::Resource) do
+        key_format { |k| k.capitalize }
+      end
+
+      Class.new(superclass) do
+        attributes
+        has_many
+        has_one
+      end
+    end
+
+    it 'formats keys accordingly' do
+      is_expected.to eq(Foo: 'bar', 'Foo-bar'.to_sym => 'baz',
+                        Baz_id: nil, Baz_type: nil,
+                        'Bar-baz_ids'.to_sym => [],
+                        'Bar-baz_types'.to_sym => [])
+    end
+  end
+end