add test

Author: Steve Lee (POWERSHELL HE/HIM) (from Dev Box)

extensions/appx/appx.tests.ps1

@@ -0,0 +1,20 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+Describe 'Tests for Appx resource discovery' {
+    BeforeAll {
+        $skip = (!$IsWindows -or ($null -eq (get-appxpackage -Name Microsoft.DesiredStateConfiguration-Preview)))
+    }
+
+    It 'Should find DSC appx resources' -Skip:$skip {
+        $out = dsc resource list | ConvertFrom-Json
+        $LASTEXITCODE | Should -Be 0
+        $found = $false
+        foreach ($resource in $out) {
+            if ($resource.directory.StartsWith("$env:ProgramFiles\WindowsApps\Microsoft.DesiredStateConfiguration-Private")) {
+                $found = $true
+                break
+            }
+        }
+    }
+}