2 files changed, 64 insertions, 0 deletions
diff --git a/lib/puppet/util/yaml.rb b/lib/puppet/util/yaml.rb
new file mode 100644
index 000000000..d0c37ae77
--- /dev/null
+++ b/lib/puppet/util/yaml.rb
@@ -0,0 +1,23 @@
+require 'yaml'
+
+module Puppet::Util::Yaml
+  if defined?(::Psych::SyntaxError)
+    YamlLoadExceptions = [::StandardError, ::Psych::SyntaxError]
+  else
+    YamlLoadExceptions = [::StandardError]
+  end
+
+  class YamlLoadError < Puppet::Error; end
+
+  def self.load_file(filename)
+    YAML.load_file(filename)
+  rescue *YamlLoadExceptions => detail
+    raise YamlLoadError.new(detail.message, detail)
+  end
+
+  def self.dump(structure, filename)
+    Puppet::Util.replace_file(filename, 0660) do |fh|
+      YAML.dump(structure, fh)
+    end
+  end
+end
diff --git a/spec/unit/util/yaml_spec.rb b/spec/unit/util/yaml_spec.rb
new file mode 100644
index 000000000..960388ade
--- /dev/null
+++ b/spec/unit/util/yaml_spec.rb
@@ -0,0 +1,41 @@
+require 'spec_helper'
+
+require 'puppet/util/yaml'
+
+describe Puppet::Util::Yaml do
+  include PuppetSpec::Files
+
+  let(:filename) { tmpfile("yaml") }
+
+  it "reads a YAML file from disk" do
+    write_file(filename, YAML.dump({ "my" => "data" }))
+
+    expect(Puppet::Util::Yaml.load_file(filename)).to eq({ "my" => "data" })
+  end
+
+  it "writes data formatted as YAML to disk" do
+    Puppet::Util::Yaml.dump({ "my" => "data" }, filename)
+
+    expect(Puppet::Util::Yaml.load_file(filename)).to eq({ "my" => "data" })
+  end
+
+  it "raises an error when the file is invalid YAML" do
+    write_file(filename, "{ invalid")
+
+    expect { Puppet::Util::Yaml.load_file(filename) }.to raise_error(Puppet::Util::Yaml::YamlLoadError)
+  end
+
+  it "raises an error when the file does not exist" do
+    expect { Puppet::Util::Yaml.load_file("no") }.to raise_error(Puppet::Util::Yaml::YamlLoadError, /No such file or directory/)
+  end
+
+  it "raises an error when the filename is illegal" do
+    expect { Puppet::Util::Yaml.load_file("not\0allowed") }.to raise_error(Puppet::Util::Yaml::YamlLoadError, /null byte/)
+  end
+
+  def write_file(name, contents)
+    File.open(name, "w") do |fh|
+      fh.write(contents)
+    end
+  end
+end