--- /dev/null
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper'
+
+describe "the intersection function" do
+ let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+ it "should exist" do
+ expect(Puppet::Parser::Functions.function("intersection")).to eq("function_intersection")
+ end
+
+ it "should raise a ParseError if there are fewer than 2 arguments" do
+ expect { scope.function_intersection([]) }.to( raise_error(Puppet::ParseError) )
+ end
+
+ it "should return the intersection of two arrays" do
+ result = scope.function_intersection([["a","b","c"],["b","c","d"]])
+ expect(result).to(eq(["b","c"]))
+ end
+end