3 files changed, 125 insertions, 0 deletions
diff --git a/README.markdown b/README.markdown
index ec4267c..68e559e 100644
--- a/README.markdown
+++ b/README.markdown
@@ -17,3 +17,32 @@ From github, download the module into your modulepath on your Puppetmaster. If y
   puppet --configprint modulepath
 
 Depending on the version of Puppet, you may need to restart the puppetmasterd (or Apache) process before the functions will work.
+
+## Functions
+
+### kwalify
+
+This function allows you to validate Puppet data structures using Kwalify 
+schemas as documented here:
+
+http://www.kuwata-lab.com/kwalify/ruby/users-guide.01.html
+
+To validate, create a schema in Puppet:
+
+    $schema = {
+      'type' => 'seq',
+      'sequence' => [
+        { 'type' => 'str' }
+      ]
+    }
+
+And create some content that you want validated:
+
+    $document = ['a', 'b', 'c']
+
+And then use the function to validate:
+
+    kwalify($schema, $document)
+
+The function will throw an error and list all validation errors if there is a
+problem otherwise it succeeds silently.
diff --git a/lib/puppet/parser/functions/kwalify.rb b/lib/puppet/parser/functions/kwalify.rb
new file mode 100644
index 0000000..7238f84
--- /dev/null
+++ b/lib/puppet/parser/functions/kwalify.rb
@@ -0,0 +1,35 @@
+#
+# kwalify.rb
+#
+
+require 'kwalify'
+
+module Puppet::Parser::Functions
+  newfunction(:kwalify, :type => :statement, :doc => <<-EOS
+This function uses kwalify to validate Puppet data structures against Kwalify
+schemas.
+    EOS
+  ) do |args|
+
+    raise(Puppet::ParseError, "kwalify(): Wrong number of arguments " +
+      "given (#{args.size} for 2)") if args.size != 2
+
+    schema = args[0]
+    document = args[1]
+
+    validator = Kwalify::Validator.new(schema)
+
+    errors = validator.validate(document)
+
+    if errors && !errors.empty?
+      error_out = []
+      for e in errors
+        error_out << "[#{e.path}] #{e.message}"
+      end
+      raise(Puppet::ParseError, "Failed kwalify schema validation:\n" + error_out.join("\n"))
+    end
+
+  end
+end
+
+# vim: set ts=2 sw=2 et :
diff --git a/spec/unit/parser/functions/kwalify_spec.rb b/spec/unit/parser/functions/kwalify_spec.rb
new file mode 100755
index 0000000..b2afa12
--- /dev/null
+++ b/spec/unit/parser/functions/kwalify_spec.rb
@@ -0,0 +1,61 @@
+#!/usr/bin/env rspec
+require 'spec_helper'
+
+describe "the kwalify function" do
+  before :all do
+    Puppet::Parser::Functions.autoloader.loadall
+  end
+
+  before :each do
+    @scope = Puppet::Parser::Scope.new
+  end
+
+  it "should exist" do
+    Puppet::Parser::Functions.function("kwalify").should == "function_kwalify"
+  end
+
+  it "should raise a ParseError if there is less than 2 arguments" do
+    lambda { @scope.function_kwalify([]) }.should( raise_error(Puppet::ParseError))
+  end
+
+  it "should validate a simple array schema" do
+    schema = { 
+      'type' => 'seq',
+      'sequence' => [
+        { 'type' => 'str' }
+      ]
+    }
+    document = ['a','b','c']
+    @scope.function_kwalify([schema, document])
+  end
+
+  it "should not validate a simple array schema when invalid" do
+    schema = { 
+      'type' => 'seq',
+      'sequence' => [
+        { 'type' => 'str' }
+      ]
+    }
+    document = ['a','b',{'a' => 'b'}]
+    lambda { @scope.function_kwalify([schema, document]) }.should(raise_error(Puppet::ParseError))
+  end
+
+  it "should validate a hash schema" do
+    schema = {
+      'type' => 'map',
+      'mapping' => {
+        'key1' => {
+          'type' => 'str',
+        },
+        'key2' => {
+          'type' => 'str',
+        },
+      }
+    }
+    document = {
+      'key1' => 'b',
+      'key2' => 'c',
+    }
+  end
+
+end