N°8763 Halt setup if non-uninstallable extension is missing (#781)

* N°8763 Halt setup if an installed & non-uninstallable extension is missing from disk

tests/php-unit-tests/unitary-tests/setup/ExtensionsMapTest.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Combodo\iTop\Test\UnitTest\Integration;
+
+use Combodo\iTop\Test\UnitTest\ItopTestCase;
+use ItopExtensionsMap;
+use ModuleDiscovery;
+
+class ExtensionsMapTest extends ItopTestCase
+{
+	protected function setUp(): void
+	{
+		parent::setUp(); // TODO: Change the autogenerated stub
+		$this->RequireOnceItopFile('/setup/unattended-install/InstallationFileService.php');
+		ModuleDiscovery::ResetCache();
+
+	}
+
+	public function testGetAllExtensionsWithPreviouslyInstalledDoesNotCrash()
+	{
+		$oExtensionsMap = new iTopExtensionsMap();
+		$aExtensions = $oExtensionsMap->GetAllExtensionsWithPreviouslyInstalled();
+		$this->assertGreaterThan(0, count($aExtensions));
+	}
+
+}