MODULES-11309 : convert a string to a resource

Author: jcpunk

lib/puppet/functions/stdlib/str2resource.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+# @summary
+#   This converts a string to a puppet resource.
+#
+#   This attempts to convert a string like 'File[/foo]' into the
+#   puppet resource `File['/foo']` as detected by the catalog.
+#
+#   Things like 'File[/foo, /bar]' are not supported as a
+#   title might contain things like ',' or ' '.  There is
+#   no clear value seperator to use.
+#
+#   This function can depend on the parse order of your
+#   manifests/modules as it inspects the catalog thus far.
+Puppet::Functions.create_function(:'stdlib::str2resource') do
+  # @param res_string The string to lookup as a resource
+  # @example
+  #   stdlib::str2resource('File[/foo]') => File[/foo]
+  # @return Puppet::Resource
+  dispatch :str2resource do
+    param 'String', :res_string
+    #return_type 'Puppet::Resource'
+    return_type 'Any'
+  end
+
+  def str2resource(res_string)
+    type_name, title = Puppet::Resource.type_and_title(res_string, nil)
+
+    resource = closure_scope.findresource(type_name, title)
+
+    if resource.nil?
+      raise(Puppet::ParseError, "stdlib::str2resource(): could not find #{type_name}[#{title}], this is parse order dependant and values should not be quoted")
+    end
+
+    return resource
+  end
+end

spec/functions/str2resource_spec.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'stdlib::str2resource' do
+  context 'when default' do
+    it { is_expected.not_to eq(nil) }
+    it { is_expected.to run.with_params.and_raise_error(ArgumentError, %r{stdlib::str2resource}) }
+  end
+
+  context 'when testing simple resource definitions exist' do
+    let :pre_condition do
+      <<-PRECOND
+        file { 'foo': }
+        file { '/foo': }
+        file { 'foot': }
+        user { 'foo': }
+      PRECOND
+    end
+
+    file_foo = Puppet::Resource.new(:file, 'foo')
+    user_foo = Puppet::Resource.new(:user, 'foo')
+
+    it { is_expected.to run.with_params('File[foo]').and_return(file_foo) }
+    it { is_expected.not_to run.with_params('File[\'foo\']') }
+    it { is_expected.not_to run.with_params('File["foo"]') }
+
+    it { is_expected.to run.with_params('User[foo]').and_return(user_foo) }
+  end
+
+  context 'when someone tries a compound definition' do
+    let :pre_condition do
+      'user { "foo, bar": }'
+    end
+
+    user_foo_bar = Puppet::Resource.new(:user, 'foo, bar')
+
+    it { is_expected.to run.with_params('User[foo, bar]').and_return(user_foo_bar) }
+  end
+
+  context 'when testing simple resource definitions no exist' do
+    it { is_expected.not_to run.with_params('File[foo]') }
+  end
+end