Implement eql and hash for Builder class

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- [#338](https://github.com/JsonApiClient/json_api_client/pull/338) - implement hash and eql? for builder class
 - [#351](https://github.com/JsonApiClient/json_api_client/pull/351) - Remove rudimental `last_result_set` relationship from serializer
 
 ## 1.13.0

lib/json_api_client/query/builder.rb

@@ -109,6 +109,20 @@ def method_missing(method_name, *args, &block)
         to_a.send(method_name, *args, &block)
       end
 
+      def hash
+        [
+          klass,
+          params
+        ].hash
+      end
+
+      def ==(other)
+        return false unless other.is_a?(self.class)
+
+        hash == other.hash
+      end
+      alias_method :eql?, :==
+
       protected
 
       def _fetch

test/unit/query_builder_test.rb

@@ -312,4 +312,24 @@ def test_build_propagate_only_path_params
     assert_equal '123', record.author_id
     assert_equal [], record.relationships.changed
   end
+
+  def test_build_hash_sum
+    a = ArticleNested.where(author_id: '123', name: 'John')
+    b = ArticleNested.where(author_id: '123', name: 'John')
+    c = ArticleNested.where(author_id: '123')
+    d = Article.where(author_id: '123', name: 'John')
+    assert(a.hash == b.hash)
+    assert_equal(false, a.hash == c.hash)
+    assert_equal(false, a.hash == d.hash)
+  end
+
+  def test_build_eql
+    a = ArticleNested.where(author_id: '123', name: 'John')
+    b = ArticleNested.where(author_id: '123', name: 'John')
+    c = ArticleNested.where(author_id: '123')
+    d = Article.where(author_id: '123', name: 'John')
+    assert(a == b)
+    assert_equal(false, a == c)
+    assert_equal(false, a == d)
+  end
 end