2 files changed, 19 insertions, 0 deletions
diff --git a/spec/ruby/library/digest/instance/append_spec.rb b/spec/ruby/library/digest/instance/append_spec.rb
new file mode 100644
index 0000000000..7f4ce3d121
--- /dev/null
+++ b/spec/ruby/library/digest/instance/append_spec.rb
@@ -0,0 +1,11 @@
+require_relative '../../../spec_helper'
+require 'digest'
+
+describe "Digest::Instance#<<" do
+  it "raises a RuntimeError if called" do
+    c = Class.new do
+      include Digest::Instance
+    end
+    -> { c.new << "test" }.should.raise(RuntimeError)
+  end
+end
diff --git a/spec/ruby/library/digest/instance/update_spec.rb b/spec/ruby/library/digest/instance/update_spec.rb
new file mode 100644
index 0000000000..d15b976213
--- /dev/null
+++ b/spec/ruby/library/digest/instance/update_spec.rb
@@ -0,0 +1,8 @@
+require_relative '../../../spec_helper'
+require 'digest'
+
+describe "Digest::Instance#update" do
+  it "is an alias of Digest::Instance#<<" do
+    Digest::Instance.instance_method(:update).should == Digest::Instance.instance_method(:<<)
+  end
+end