Determine root_home without shelling out

This uses Ruby's Etc library to determine the root home. This avoids
shelling out and writing multiple implementations.

Author: ekohl

lib/facter/root_home.rb

@@ -1,49 +1,11 @@
 # frozen_string_literal: true
 
-# root_home.rb
-module Facter::Util::RootHome
-  # @summary
-  #   A facter fact to determine the root home directory.
-  #   This varies on PE supported platforms and may be
-  #   reconfigured by the end user.
-  class << self
-    # determines the root home directory
-    def returnt_root_home
-      root_ent = Facter::Core::Execution.execute('getent passwd root')
-      # The home directory is the sixth element in the passwd entry
-      # If the platform doesn't have getent, root_ent will be nil and we should
-      # return it straight away.
-      root_ent && root_ent.split(':')[5]
-    end
-  end
-end
-
-Facter.add(:root_home) do
-  setcode { Facter::Util::RootHome.returnt_root_home }
-end
-
-Facter.add(:root_home) do
-  confine kernel: :darwin
-  setcode do
-    str = Facter::Core::Execution.execute('dscacheutil -q user -a name root')
-    hash = {}
-    str.split("\n").each do |pair|
-      key, value = pair.split(%r{:})
-      hash[key] = value
-    end
-    hash['dir'].strip
-  end
-end
-
 Facter.add(:root_home) do
-  confine kernel: :aix
-  root_home = nil
   setcode do
-    str = Facter::Core::Execution.execute('lsuser -c -a home root')
-    str&.split("\n")&.each do |line|
-      next if %r{^#}.match?(line)
-      root_home = line.split(%r{:})[1]
-    end
-    root_home
+    require 'etc'
+  rescue LoadError
+  # Unavailable on platforms like Windows
+  else
+    Etc.getpwnam('root').dir
   end
 end

spec/unit/facter/root_home_spec.rb

@@ -2,66 +2,20 @@
 
 require 'spec_helper'
 require 'facter/root_home'
-describe 'Root Home Specs' do
-  describe Facter::Util::RootHome do
-    context 'when solaris' do
-      let(:root_ent) { 'root:x:0:0:Super-User:/:/sbin/sh' }
-      let(:expected_root_home) { '/' }
 
-      it 'returns /' do
-        expect(Facter::Core::Execution).to receive(:execute).with('getent passwd root').and_return(root_ent)
-        expect(described_class.returnt_root_home).to eq(expected_root_home)
-      end
-    end
-    context 'when linux' do
-      let(:root_ent) { 'root:x:0:0:root:/root:/bin/bash' }
-      let(:expected_root_home) { '/root' }
+describe 'root_home', type: :fact do
+  subject { Facter.fact(:root_home) }
 
-      it 'returns /root' do
-        expect(Facter::Core::Execution).to receive(:execute).with('getent passwd root').and_return(root_ent)
-        expect(described_class.returnt_root_home).to eq(expected_root_home)
-      end
-    end
-    context 'when windows' do
-      it 'is nil on windows' do
-        expect(Facter::Core::Execution).to receive(:execute).with('getent passwd root').and_return(nil)
-        expect(described_class.returnt_root_home).to be_nil
-      end
-    end
-  end
-
-  describe 'root_home', type: :fact do
-    before(:each) { Facter.clear }
-    after(:each) { Facter.clear }
-
-    context 'when macosx' do
-      before(:each) do
-        allow(Facter.fact(:kernel)).to receive(:value).and_return('Darwin')
-        allow(Facter.fact(:osfamily)).to receive(:value).and_return('Darwin')
-      end
-      let(:expected_root_home) { '/var/root' }
+  before(:each) { Facter.clear }
+  after(:each) { Facter.clear }
 
-      sample_dscacheutil = File.read(fixtures('dscacheutil', 'root'))
-
-      it 'returns /var/root' do
-        allow(Facter::Core::Execution).to receive(:execute).with('dscacheutil -q user -a name root').and_return(sample_dscacheutil)
-        expect(Facter.fact(:root_home).value).to eq(expected_root_home)
-      end
-    end
-
-    context 'when aix' do
-      before(:each) do
-        allow(Facter.fact(:kernel)).to receive(:value).and_return('AIX')
-        allow(Facter.fact(:osfamily)).to receive(:value).and_return('AIX')
-      end
-      let(:expected_root_home) { '/root' }
+  context 'when Windows', if: Facter.value(:kernel) == 'Windows' do
+    it { expect(subject.value).to be(nil) }
+  end
 
-      sample_lsuser = File.read(fixtures('lsuser', 'root'))
+  context 'when non-Windows', if: Facter.value(:kernel) != 'Windows' do
+    let(:expected) { Facter.value(:kernel) == 'Darwin' ? '/var/root' : '/root' }
 
-      it 'returns /root' do
-        allow(Facter::Core::Execution).to receive(:execute).with('lsuser -c -a home root').and_return(sample_lsuser)
-        expect(Facter.fact(:root_home).value).to eq(expected_root_home)
-      end
-    end
+    it { expect(subject.value).to eq(expected) }
   end
 end