--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/modules/stdlib/spec/functions/is_domain_name_spec.rb	Sat Mar 14 20:09:45 2015 +0000
@@ -0,0 +1,64 @@
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper'
+
+describe "the is_domain_name function" do
+  let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+  it "should exist" do
+    expect(Puppet::Parser::Functions.function("is_domain_name")).to eq("function_is_domain_name")
+  end
+
+  it "should raise a ParseError if there is less than 1 arguments" do
+    expect { scope.function_is_domain_name([]) }.to( raise_error(Puppet::ParseError))
+  end
+
+  it "should return true if a valid short domain name" do
+    result = scope.function_is_domain_name(["x.com"])
+    expect(result).to(be_truthy)
+  end
+
+  it "should return true if the domain is ." do
+    result = scope.function_is_domain_name(["."])
+    expect(result).to(be_truthy)
+  end
+
+  it "should return true if the domain is x.com." do
+    result = scope.function_is_domain_name(["x.com."])
+    expect(result).to(be_truthy)
+  end
+
+  it "should return true if a valid domain name" do
+    result = scope.function_is_domain_name(["foo.bar.com"])
+    expect(result).to(be_truthy)
+  end
+
+  it "should allow domain parts to start with numbers" do
+    result = scope.function_is_domain_name(["3foo.2bar.com"])
+    expect(result).to(be_truthy)
+  end
+
+  it "should allow domain to end with a dot" do
+    result = scope.function_is_domain_name(["3foo.2bar.com."])
+    expect(result).to(be_truthy)
+  end
+
+  it "should allow a single part domain" do
+    result = scope.function_is_domain_name(["orange"])
+    expect(result).to(be_truthy)
+  end
+
+  it "should return false if domain parts start with hyphens" do
+    result = scope.function_is_domain_name(["-3foo.2bar.com"])
+    expect(result).to(be_falsey)
+  end
+
+  it "should return true if domain contains hyphens" do
+    result = scope.function_is_domain_name(["3foo-bar.2bar-fuzz.com"])
+    expect(result).to(be_truthy)
+  end
+
+  it "should return false if domain name contains spaces" do
+    result = scope.function_is_domain_name(["not valid"])
+    expect(result).to(be_falsey)
+  end
+end