CFINSPEC-80: Define aliased_to matcher and add unit test

Signed-off-by: Sonu Saha <sonu.saha@progress.com>

lib/inspec/resources/mail_alias.rb

@@ -32,16 +32,11 @@ module Inspec::Resources
       "mail_alias #{resource_id}"
     end
 
-    def is_aliased_to?(alias_value)
-      # positive or negative expectations specific to this resource instance
-      true
-    end
+    def aliased_to?(alias_value)
+      cmd = inspec.command("cat /etc/aliases | grep #{@alias_key}")
+      raise Inspec::Exceptions::ResourceFailed, "#{@alias_key} is not a valid key in the aliases" if cmd.exit_status.to_i != 0
 
-    private
-
-    # Methods to help the resource's public methods
-    def helper_method
-      # Add anything you need here
+      alias_value == cmd.stdout.split(":").map(&:strip)[1]
     end
   end
 end

test/fixtures/cmd/mail-alias

@@ -0,0 +1 @@
+daemon:		root

test/helpers/mock_loader.rb

@@ -383,6 +383,8 @@ class MockLoader
       "cgget -n -r cpuset.cpus carrotking" => cmd.call("cgget-n-r"),
       "cgget -n -r memory.stat carrotking" => cmd.call("cgget-n-r-stat"),
       %{sh -c 'type "cgget"'} => empty.call,
+      # mail_alias
+      "cat /etc/aliases | grep daemon" => cmd.call("mail-alias"),
       # apache_conf
       "sh -c 'find /etc/apache2/ports.conf -type f -maxdepth 1'" => cmd.call("find-apache2-ports-conf"),
       "sh -c 'find /etc/httpd/conf.d/*.conf -type f -maxdepth 1'" => cmd.call("find-httpd-ssl-conf"),

test/unit/resources/mail_alias_test.rb

@@ -3,18 +3,24 @@ require "#{Inspec.src_root}/test/helper"
 require_relative "../../../lib/inspec/resources/mail_alias"
 
 describe Inspec::Resources::Mailalias do
-  it "check mail alias on ubuntu" do
+  it "check mail_alias on ubuntu" do
     resource = MockLoader.new(:ubuntu).load_resource("mail_alias", "daemon")
-    _(resource.is_aliased_to?("root")).must_equal true
+    _(resource.aliased_to?("root")).must_equal true
   end
 
-  it "check mail alias on macos" do
+  it "check mail_alias on macos" do
     resource = MockLoader.new(:macos10_10).load_resource("mail_alias", "daemon")
-    _(resource.is_aliased_to?("root")).must_equal true
+    _(resource.aliased_to?("root")).must_equal true
   end
 
-  it "check mail alias on freebsd" do
+  it "check mail_alias on freebsd" do
     resource = MockLoader.new(:freebsd11).load_resource("mail_alias", "daemon")
-    _(resource.is_aliased_to?("root")).must_equal true
+    _(resource.aliased_to?("root")).must_equal true
+  end
+
+  it "check mail_alias on ubuntu with a key that is not included as an alias" do
+    resource = MockLoader.new(:ubuntu).load_resource("mail_alias", "cheesecake")
+    ex = _ { resource.aliased_to?("root") }.must_raise(Inspec::Exceptions::ResourceFailed)
+    _(ex.message).must_include "cheesecake is not a valid key in the aliases"
   end
 end