From 5f1ddf2a96e3ff2b0c04ef92467749d5bfaaf6ca Mon Sep 17 00:00:00 2001
From: Olivier Bellone <ob@stripe.com>
Date: Mon, 12 Feb 2018 11:20:19 -0800
Subject: [PATCH] Skip calling to_hash for nil

---
 lib/stripe/stripe_object.rb       |  2 +-
 test/stripe/stripe_object_test.rb | 47 +++++++++++++++++++++----------
 2 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/lib/stripe/stripe_object.rb b/lib/stripe/stripe_object.rb
index 18300480..85827ffb 100644
--- a/lib/stripe/stripe_object.rb
+++ b/lib/stripe/stripe_object.rb
@@ -116,7 +116,7 @@ module Stripe
 
     def to_hash
       maybe_to_hash = lambda do |value|
-        value.respond_to?(:to_hash) ? value.to_hash : value
+        value && value.respond_to?(:to_hash) ? value.to_hash : value
       end
 
       @values.each_with_object({}) do |(key, value), acc|
diff --git a/test/stripe/stripe_object_test.rb b/test/stripe/stripe_object_test.rb
index 5e6429f5..75f6d04f 100644
--- a/test/stripe/stripe_object_test.rb
+++ b/test/stripe/stripe_object_test.rb
@@ -115,23 +115,40 @@ module Stripe
       end
     end
 
-    should "recursively call to_hash on its values" do
-      # deep nested hash (when contained in an array) or StripeObject
-      nested_hash = { id: 7, foo: "bar" }
-      nested = Stripe::StripeObject.construct_from(nested_hash)
+    context "#to_hash" do
+      should "skip calling to_hash on nil" do
+        module NilWithToHash
+          def to_hash
+            raise "Can't call to_hash on nil"
+          end
+        end
+        # include is private in Ruby 2.0
+        NilClass.send(:include, NilWithToHash)
 
-      obj = Stripe::StripeObject.construct_from(id: 1,
-                                                # simple hash that contains a StripeObject to help us test deep
-                                                # recursion
-                                                nested: { object: "list", data: [nested] },
-                                                list: [nested])
+        hash_with_nil = { id: 3, foo: nil }
+        obj = StripeObject.construct_from(hash_with_nil)
+        expected_hash = { id: 3, foo: nil }
+        assert_equal expected_hash, obj.to_hash
+      end
 
-      expected_hash = {
-        id: 1,
-        nested: { object: "list", data: [nested_hash] },
-        list: [nested_hash],
-      }
-      assert_equal expected_hash, obj.to_hash
+      should "recursively call to_hash on its values" do
+        # deep nested hash (when contained in an array) or StripeObject
+        nested_hash = { id: 7, foo: "bar" }
+        nested = Stripe::StripeObject.construct_from(nested_hash)
+
+        obj = Stripe::StripeObject.construct_from(id: 1,
+                                                  # simple hash that contains a StripeObject to help us test deep
+                                                  # recursion
+                                                  nested: { object: "list", data: [nested] },
+                                                  list: [nested])
+
+        expected_hash = {
+          id: 1,
+          nested: { object: "list", data: [nested_hash] },
+          list: [nested_hash],
+        }
+        assert_equal expected_hash, obj.to_hash
+      end
     end
 
     should "assign question mark accessors for booleans" do