Allow underscore navigation (#193)

* Allow underscore navigation

* rubocop

Author: mkon

.rubocop.yml

@@ -10,6 +10,11 @@ Layout/SpaceInsideHashLiteralBraces:
 Lint/AssignmentInCondition:
   Enabled: false
 
+Metrics/CyclomaticComplexity:
+  Max: 9
+Metrics/PerceivedComplexity:
+  Max: 9
+
 Style/ClassAndModuleChildren:
   Enabled: false
 Style/ConditionalAssignment:

lib/ja2r/element.rb

@@ -3,7 +3,8 @@ class Element
     def initialize(origin_data, options = {})
       @origin_data = origin_data.with_indifferent_access
       @options = options
-      @relationships = origin_data['relationships'] ? convert_relationships(origin_data['relationships']) : {}
+      @relationships = origin_data['relationships']&.then { |rd| convert_relationships(rd) } || {}
+      build_references
     end
 
     attr_reader :origin_data, :relationships
@@ -39,18 +40,31 @@ def type
 
     private
 
-    def method_missing(symbol, *args)
-      return attributes[symbol] if attributes&.key? symbol
-      return relationships[symbol] if relationships&.key? symbol
+    def build_references
+      @references = {}.with_indifferent_access
+      attributes&.each_key do |key|
+        @references[key] ||= {attribute: key}
+        @references[key.underscore] ||= {attribute: key}
+      end
+      relationships&.each_key do |key|
+        @references[key] ||= {relationship: key}
+        @references[key.underscore] ||= {relationship: key}
+      end
+    end
 
-      safe_traverse? ? nil : super
+    def method_missing(symbol, *args)
+      case @references[symbol]
+      in attribute:
+        attributes[attribute]
+      in relationship:
+        relationships[relationship]
+      else
+        safe_traverse? ? nil : super
+      end
     end
 
     def respond_to_missing?(symbol, include_all = false)
-      return true if attributes&.key?(symbol)
-      return true if relationships&.key?(symbol)
-
-      safe_traverse? || super
+      @references.key?(symbol) || safe_traverse? || super
     end
 
     def safe_traverse?

spec/fixtures/singular.json

@@ -12,6 +12,12 @@
         "example": true
       },
       "relationships":{
+         "best-friend":{
+            "data":{
+              "id":"1005",
+              "type":"persons"
+            }
+         },
          "sister":{
             "data":{
               "id":"1002",
@@ -34,6 +40,13 @@
             "name":"Lisa"
          }
       },
+      {
+         "id":"1005",
+         "type":"persons",
+         "attributes":{
+            "name":"Milhouse"
+         }
+      },
       {
          "id":"998",
          "type":"persons",

spec/ja2r/element_spec.rb

@@ -43,4 +43,30 @@
       end
     end
   end
+
+  context 'with dashes in the keys' do
+    let(:origin_data) do
+      {
+        'id' => 'some-id',
+        'attributes' => {
+          'foo-field' => 'foo-value',
+          'bar-field' => {
+            'bar-value' => true
+          }
+        },
+        'relationships' => {
+          'some-one' => {
+            'data' => {'id' => '1122', 'type' => 'some-ones'}
+          }
+        }
+      }
+    end
+
+    it 'allows navigation with underscore' do
+      expect(element.foo_field).to eq 'foo-value'
+      expect(element.bar_field).to eq('bar-value' => true)
+      expect(element.some_one).to be_a(described_class)
+      expect(element.some_one.type).to eq('some-ones')
+    end
+  end
 end

spec/ja2r_spec.rb

@@ -5,6 +5,7 @@
   it 'can handle singular relations' do
     ele = described_class.parse payload
     expect(ele.id).to eq '1001'
+    expect(ele.best_friend.name).to eq 'Milhouse'
     expect(ele.sister.id).to eq '1002'
     expect(ele.sister.name).to eq 'Lisa'
     expect(ele.father.id).to eq '998'