(FEAT) Add function parsepson

REFERENCE.md

@@ -140,6 +140,8 @@ true boolean.
 Puppet structure
 * [`parsejson`](#parsejson): This function accepts JSON as a string and converts it into the correct
 Puppet structure.
+* [`parsepson`](#parsepson): This function accepts PSON, a Puppet variant of JSON, as a string and 
+converts it into the correct Puppet structure.
 * [`parseyaml`](#parseyaml): This function accepts YAML as a string and converts it into the correct
 Puppet structure.
 * [`pick`](#pick): This function will return
@@ -3939,6 +3941,53 @@ Type: Ruby 3.x API
   The optional second argument can be used to pass a default value that will
   be returned if the parsing of YAML string have failed.
 
+### <a name="parsepson"></a>`parsepson`
+
+Type: Ruby 4.x API
+
+This function accepts PSON as a string and converts it into the correct
+Puppet structure
+
+#### Examples
+
+##### How to parse pson
+
+```puppet
+$data = parsepson('{"a":"1","b":"2"}')
+```
+
+For more information on PSON please see the following link:
+https://puppet.com/docs/puppet/7/http_api/pson.html
+
+#### `parsepson(String $pson_string, Optional[Any] $default)`
+
+The parseson function.
+
+Returns: `Data`
+
+##### Examples
+
+###### How to parse pson
+
+```puppet
+$data = parsepson('{"a":"1","b":"2"}')
+```
+
+For more information on PSON please see the following link:
+https://puppet.com/docs/puppet/7/http_api/pson.html
+
+##### `pson_string`
+
+Data type: `String[1]`
+
+A valid PSON string
+
+##### `default`
+
+Data type: `Optional[Any]`
+
+An optional default to return if parsing the pson_string fails
+
 #### `parseyaml()`
 
 > *Note:*

lib/puppet/functions/parsepson.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+# @summary
+#   This function accepts PSON, a Puppet variant of JSON, as a string and converts
+#   it into the correct Puppet structure
+#
+# @example How to parse pson
+#   $data = parsepson('{"a":"1","b":"2"}')
+#
+# For more information on PSON please see the following link:
+# https://puppet.com/docs/puppet/7/http_api/pson.html
+#
+Puppet::Functions.create_function(:parsepson) do
+  # @param pson_string A valid PSON string
+  # @param default An optional default to return if parsing the pson_string fails
+  # @return [Data]
+  dispatch :parsepson do
+    param          'String[1]', :pson_string
+    optional_param 'Any',       :default
+  end
+
+  def parsepson(pson_string, default = :no_default_provided)
+    PSON.load(pson_string)
+  rescue StandardError => err
+    Puppet.debug("Parsing PSON failed with error: #{err.message}")
+    raise err if default == :no_default_provided
+    default
+  end
+end

spec/functions/parsepson_spec.rb

@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'parsepson' do
+  it 'exists' do
+    is_expected.not_to eq(nil)
+  end
+
+  it 'raises an error if called without any arguments' do
+    is_expected.to run.with_params
+                      .and_raise_error(%r{'parsepson' expects between 1 and 2 arguments, got none}i)
+  end
+
+  context 'with correct PSON data' do
+    it 'is able to parse PSON data with a Hash' do
+      is_expected.to run.with_params('{"a":"1","b":"2"}')
+                        .and_return('a' => '1', 'b' => '2')
+    end
+
+    it 'is able to parse PSON data with an Array' do
+      is_expected.to run.with_params('["a","b","c"]')
+                        .and_return(['a', 'b', 'c'])
+    end
+
+    it 'is able to parse empty PSON values' do
+      actual_array = ['[]', '{}']
+      expected = [[], {}]
+      actual_array.each_with_index do |actual, index|
+        is_expected.to run.with_params(actual).and_return(expected[index])
+      end
+    end
+
+    it 'is able to parse PSON data with a mixed structure' do
+      is_expected.to run.with_params('{"a":"1","b":2,"c":{"d":[true,false]}}')
+                        .and_return('a' => '1', 'b' => 2, 'c' => { 'd' => [true, false] })
+    end
+
+    it 'is able to parse PSON data with a UTF8 and double byte characters' do
+      is_expected.to run.with_params('{"×":"これ","ý":"記号","です":{"©":["Á","ß"]}}')
+                        .and_return('×' => 'これ', 'ý' => '記号', 'です' => { '©' => ['Á', 'ß'] })
+    end
+
+    it 'does not return the default value if the data was parsed correctly' do
+      is_expected.to run.with_params('{"a":"1"}', 'default_value')
+                        .and_return('a' => '1')
+    end
+  end
+
+  context 'with incorrect PSON data' do
+    it 'raises an error with invalid PSON and no default' do
+      is_expected.to run.with_params('invalid')
+                        .and_raise_error(PSON::ParserError)
+    end
+
+    it 'returns the default value for an invalid PSON and a given default' do
+      is_expected.to run.with_params('invalid', 'default_value')
+                        .and_return('default_value')
+    end
+
+    it 'supports a structure for a default value' do
+      is_expected.to run.with_params('invalid', 'a' => '1')
+                        .and_return('a' => '1')
+    end
+  end
+end