Update to ruby/spec@944ea57

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66622 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/ruby/core/array/difference_spec.rb

@@ -0,0 +1,24 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+require_relative 'shared/difference'
+
+ruby_version_is "2.6" do
+  describe "Array#difference" do
+    it_behaves_like :array_binary_difference, :-
+
+    it "returns a copy when called without any parameter" do
+      x = [1, 2, 3, 2]
+      x.difference.should == x
+      x.difference.should_not equal x
+    end
+
+    it "does not return subclass instances for Array subclasses" do
+      ArraySpecs::MyArray[1, 2, 3].difference.should be_an_instance_of(Array)
+    end
+
+    it "accepts multiple arguments" do
+      x = [1, 2, 3, 1]
+      x.difference([], [0, 1], [3, 4], [3]).should == [2]
+    end
+  end
+end