Raise argument error when args to find are nil, fixes instances where the collection endpoint is called instead where arguments are nil

Author: raldred

lib/json_api_client/query/builder.rb

@@ -94,6 +94,7 @@ def to_a
       alias all to_a
 
       def find(args = {})
+        raise ArgumentError, "Arguments cannot be nil" if args.nil?
         case args
         when Hash
           where(args)

test/unit/finding_test.rb

@@ -77,4 +77,10 @@ def test_find_all
     assert_equal ["2", "3"], articles.map(&:id)
   end
 
+  def test_find_nil
+    assert_raises ArgumentError do
+      Article.find(nil)
+    end
+  end
+
 end