add a new function & tests for that function

lib/puppet/parser/functions/array_del.rb

@@ -0,0 +1,11 @@
+Puppet::Parser::Functions::newfunction(
+  :array_del,
+  :type => :rvalue,
+  :doc => "Deletes items from an array
+
+    Example: array_del(['a','b'],'b') -> ['a']"
+) do |args|
+  raise Puppet::ParseError, 'array_del() needs two arguments' if args.length != 2
+  (res=args[0].dup).to_a.delete(args[1])
+  res
+end

spec/spec.opts

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+--format
+s
+--colour
+--loadby
+mtime
+--backtrace

spec/spec_helper.rb

@@ -0,0 +1,16 @@
+require 'pathname'
+dir = Pathname.new(__FILE__).parent
+$LOAD_PATH.unshift(dir, dir + 'lib', dir + '../lib')
+require 'puppet'
+gem 'rspec', '>= 1.2.9'
+require 'spec/autorun'
+
+Dir[File.join(File.dirname(__FILE__), 'support', '*.rb')].each do |support_file|
+  require support_file
+end
+
+# We need this because the RAL uses 'should' as a method.  This
+# allows us the same behaviour but with a different method name.
+class Object
+    alias :must :should
+end

spec/unit/parser/functions/array_del.rb

@@ -0,0 +1,39 @@
+#! /usr/bin/env ruby
+
+require File.dirname(__FILE__) + '/../../../spec_helper'
+
+describe "the array_del function" do
+
+  before :each do
+    @scope = Puppet::Parser::Scope.new
+  end
+
+  it "should exist" do
+    Puppet::Parser::Functions.function("array_del").should == "function_array_del"
+  end
+
+  it "should raise a ParseError if there is less than 2 arguments" do
+    lambda { @scope.function_array_del(["foo"]) }.should( raise_error(Puppet::ParseError))
+  end
+
+  it "should raise a ParseError if there is more than 2 arguments" do
+    lambda { @scope.function_array_del(["foo", "bar", "gazonk"]) }.should( raise_error(Puppet::ParseError))
+  end
+
+  it "should remove an item if it's present" do
+    result = @scope.function_array_del(['a','b'],'b')
+    result.should(eql(['a']))
+  end
+
+  it "should do nothing if an item is not present" do
+    result = @scope.function_array_del(['a','b'],'c')
+    result.should(eql(['a','b']))
+  end
+
+  it "should leave the argument untouched" do
+    a = ['a','b']
+    result = @scope.function_array_del(a,'b')
+    a.should(eql(['a','b']))
+  end
+
+end