Added basename() based on Ruby's File.basename

Based on dirname code.  Includes RSpec tests and docs.

README.markdown

@@ -84,6 +84,13 @@ If you want to use a standardized set of run stages for Puppet, `include stdlib`
 Requires an action ('encode', 'decode') and either a plain or base64-encoded
 string. *Type*: rvalue
 
+* `basename`: Returns the `basename` of a path (optionally stripping an extension). For example:
+  * ('/path/to/a/file.ext') returns 'file.ext'
+  * ('relative/path/file.ext') returns 'file.ext'
+  * ('/path/to/a/file.ext', '.ext') returns 'file'
+
+  *Type*: rvalue
+
 * `bool2num`: Converts a boolean to a number. Converts values:
   * 'false', 'f', '0', 'n', and 'no' to 0.
   * 'true', 't', '1', 'y', and 'yes' to 1.

lib/puppet/parser/functions/basename.rb

@@ -0,0 +1,34 @@
+module Puppet::Parser::Functions
+  newfunction(:basename, :type => :rvalue, :doc => <<-EOS
+    Strips directory (and optional suffix) from a filename
+    EOS
+  ) do |arguments|
+
+    if arguments.size < 1 then
+      raise(Puppet::ParseError, "basename(): No arguments given")
+    elsif arguments.size > 2 then
+      raise(Puppet::ParseError, "basename(): Too many arguments given (#{arguments.size})")
+    else
+
+      unless arguments[0].is_a?(String)
+        raise(Puppet::ParseError, 'basename(): Requires string as first argument')
+      end
+
+      if arguments.size == 1 then
+        rv = File.basename(arguments[0])
+      elsif arguments.size == 2 then
+
+        unless arguments[1].is_a?(String)
+          raise(Puppet::ParseError, 'basename(): Requires string as second argument')
+        end
+
+        rv = File.basename(arguments[0], arguments[1])
+      end
+
+    end
+
+    return rv
+  end
+end
+
+# vim: set ts=2 sw=2 et :

spec/unit/puppet/parser/functions/basename_spec.rb

@@ -0,0 +1,46 @@
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper'
+
+describe "the basename function" do
+  let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+  it "should exist" do
+    Puppet::Parser::Functions.function("basename").should == "function_basename"
+  end
+
+  it "should raise a ParseError if there is less than 1 argument" do
+    lambda { scope.function_basename([]) }.should( raise_error(Puppet::ParseError))
+  end
+
+  it "should raise a ParseError if there are more than 2 arguments" do
+    lambda { scope.function_basename(['a', 'b', 'c']) }.should( raise_error(Puppet::ParseError))
+  end
+
+  it "should return basename for an absolute path" do
+    result = scope.function_basename(['/path/to/a/file.ext'])
+    result.should(eq('file.ext'))
+  end
+
+  it "should return basename for a relative path" do
+    result = scope.function_basename(['path/to/a/file.ext'])
+    result.should(eq('file.ext'))
+  end
+
+  it "should strip extention when extension specified (absolute path)" do
+    result = scope.function_basename(['/path/to/a/file.ext', '.ext'])
+    result.should(eq('file'))
+  end
+
+  it "should strip extention when extension specified (relative path)" do
+    result = scope.function_basename(['path/to/a/file.ext', '.ext'])
+    result.should(eq('file'))
+  end
+
+  it "should complain about non-string first argument" do
+    lambda { scope.function_basename([[]]) }.should( raise_error(Puppet::ParseError))
+  end
+
+  it "should complain about non-string second argument" do
+    lambda { scope.function_basename(['/path/to/a/file.ext', []]) }.should( raise_error(Puppet::ParseError))
+  end
+end