When restarting after update if service start fails update app will fallback to console.

NzbDrone.Update.Test/InstallUpdateServiceFixture.cs

@@ -0,0 +1,57 @@
+using System;
+using System.IO;
+using FluentAssertions;
+using NUnit.Framework;
+using NzbDrone.Common;
+using NzbDrone.Test.Common;
+using NzbDrone.Update.UpdateEngine;
+
+namespace NzbDrone.Update.Test
+{
+    [TestFixture]
+    public class InstallUpdateServiceFixture : TestBase<InstallUpdateService>
+    {
+        [SetUp]
+        public void Setup()
+        {
+            Mocker.GetMock<IEnvironmentProvider>()
+                .Setup(c => c.SystemTemp).Returns(@"C:\Temp\");
+        }
+
+        [TestCase(null)]
+        [TestCase("")]
+        [TestCase(" ")]
+        public void update_should_throw_target_folder_is_blank(string target)
+        {
+            Assert.Throws<ArgumentException>(() => Subject.Start(target))
+            .Message.Should().StartWith("Target folder can not be null or empty");
+        }
+
+        [Test]
+        public void update_should_throw_if_target_folder_doesnt_exist()
+        {
+            string targetFolder = "c:\\NzbDrone\\";
+
+            Assert.Throws<DirectoryNotFoundException>(() => Subject.Start(targetFolder))
+            .Message.Should().StartWith("Target folder doesn't exist");
+        }
+
+        [Test]
+        public void update_should_throw_if_update_folder_doesnt_exist()
+        {
+            const string sandboxFolder = @"C:\Temp\NzbDrone_update\nzbdrone";
+            const string targetFolder = "c:\\NzbDrone\\";
+
+            Mocker.GetMock<IDiskProvider>()
+                .Setup(c => c.FolderExists(targetFolder))
+                .Returns(true);
+
+            Mocker.GetMock<IDiskProvider>()
+               .Setup(c => c.FolderExists(sandboxFolder))
+               .Returns(false);
+
+            Assert.Throws<DirectoryNotFoundException>(() => Subject.Start(targetFolder))
+                .Message.Should().StartWith("Update folder doesn't exist");
+        }
+    }
+}