SEBWIN-674: Extended unit tests for third-party application logic.

SafeExamBrowser.Applications.UnitTests/ExternalApplicationInstanceTests.cs

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2023 ETH Zürich, Educational Development and Technology (LET)
+ * 
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
+using SafeExamBrowser.Core.Contracts.Resources.Icons;
+using SafeExamBrowser.Logging.Contracts;
+using SafeExamBrowser.WindowsApi.Contracts;
+
+namespace SafeExamBrowser.Applications.UnitTests
+{
+	[TestClass]
+	public class ExternalApplicationInstanceTests
+	{
+		private NativeIconResource icon;
+		private Mock<ILogger> logger;
+		private Mock<INativeMethods> nativeMethods;
+		private Mock<IProcess> process;
+		private ExternalApplicationInstance sut;
+
+		[TestInitialize]
+		public void Initialize()
+		{
+			icon = new NativeIconResource();
+			logger = new Mock<ILogger>();
+			nativeMethods = new Mock<INativeMethods>();
+			process = new Mock<IProcess>();
+
+			sut = new ExternalApplicationInstance(icon, logger.Object, nativeMethods.Object, process.Object, 1);
+		}
+
+		[TestMethod]
+		public void Terminate_MustDoNothingIfAlreadyTerminated()
+		{
+			process.SetupGet(p => p.HasTerminated).Returns(true);
+
+			sut.Terminate();
+
+			process.Verify(p => p.TryClose(It.IsAny<int>()), Times.Never());
+			process.Verify(p => p.TryKill(It.IsAny<int>()), Times.Never());
+		}
+
+		[TestMethod]
+		public void Terminate_MustLogIfTerminationFailed()
+		{
+			process.Setup(p => p.TryClose(It.IsAny<int>())).Returns(false);
+			process.Setup(p => p.TryKill(It.IsAny<int>())).Returns(false);
+			process.SetupGet(p => p.HasTerminated).Returns(false);
+
+			sut.Terminate();
+
+			logger.Verify(l => l.Warn(It.IsAny<string>()), Times.AtLeastOnce);
+			process.Verify(p => p.TryClose(It.IsAny<int>()), Times.AtLeastOnce());
+			process.Verify(p => p.TryKill(It.IsAny<int>()), Times.AtLeastOnce());
+		}
+	}
+}

SafeExamBrowser.Applications.UnitTests/ExternalApplicationTests.cs

@@ -82,6 +82,18 @@ namespace SafeExamBrowser.Applications.UnitTests
 			Assert.IsTrue(windows.Any(w => w.Handle == new IntPtr(234)));
 			Assert.IsTrue(windows.Any(w => w.Handle == new IntPtr(345)));
 			Assert.IsTrue(windows.Any(w => w.Handle == new IntPtr(567)));
+
+			nativeMethods.Setup(n => n.GetOpenWindows()).Returns(openWindows.Take(4));
+			process2.Raise(p => p.Terminated += null, default(int));
+
+			sync.WaitOne();
+
+			windows = sut.GetWindows();
+
+			Assert.AreEqual(2, windows.Count());
+			Assert.IsTrue(windows.Any(w => w.Handle == new IntPtr(234)));
+			Assert.IsTrue(windows.Any(w => w.Handle == new IntPtr(345)));
+			Assert.IsTrue(windows.All(w => w.Handle != new IntPtr(567)));
 		}
 
 		[TestMethod]
@@ -127,7 +139,7 @@ namespace SafeExamBrowser.Applications.UnitTests
 		[TestMethod]
 		public void Start_MustRemoveInstanceCorrectlyWhenTerminated()
 		{
-			var eventRaised = false;
+			var eventCount = 0;
 			var openWindows = new List<IntPtr> { new IntPtr(123), new IntPtr(234), new IntPtr(456), new IntPtr(345), new IntPtr(567), new IntPtr(789), };
 			var process = new Mock<IProcess>();
 			var sync = new AutoResetEvent(false);
@@ -141,7 +153,7 @@ namespace SafeExamBrowser.Applications.UnitTests
 
 			sut.WindowsChanged += () =>
 			{
-				eventRaised = true;
+				eventCount++;
 				sync.Set();
 			};
 
@@ -154,7 +166,7 @@ namespace SafeExamBrowser.Applications.UnitTests
 
 			process.Raise(p => p.Terminated += null, default(int));
 
-			Assert.IsTrue(eventRaised);
+			Assert.AreEqual(2, eventCount);
 			Assert.AreEqual(0, sut.GetWindows().Count());
 		}
 

SafeExamBrowser.Applications.UnitTests/ExternalApplicationWindowTests.cs

@@ -47,12 +47,16 @@ namespace SafeExamBrowser.Applications.UnitTests
 			var titleChanged = false;
 
 			nativeMethods.Setup(m => m.GetWindowIcon(It.IsAny<IntPtr>())).Returns(new IntPtr(456));
+			nativeMethods.Setup(m => m.GetWindowTitle((It.IsAny<IntPtr>()))).Returns("Some New Window Title");
 
 			sut.IconChanged += (_) => iconChanged = true;
 			sut.TitleChanged += (_) => titleChanged = true;
 
 			sut.Update();
 
+			nativeMethods.Verify(m => m.GetWindowIcon(handle), Times.Once);
+			nativeMethods.Verify(m => m.GetWindowTitle(handle), Times.Once);
+
 			Assert.IsTrue(iconChanged);
 			Assert.IsTrue(titleChanged);
 		}

SafeExamBrowser.Applications.UnitTests/SafeExamBrowser.Applications.UnitTests.csproj

@@ -85,6 +85,7 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ExternalApplicationTests.cs" />
     <Compile Include="ExternalApplicationWindowTests.cs" />
+    <Compile Include="ExternalApplicationInstanceTests.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="app.config" />

SafeExamBrowser.Applications/ExternalApplicationInstance.cs

@@ -162,8 +162,11 @@ namespace SafeExamBrowser.Applications
 
 		private void FinalizeEvents()
 		{
-			timer.Elapsed -= Timer_Elapsed;
+			if (timer != default)
-			timer.Stop();
+			{
+				timer.Elapsed -= Timer_Elapsed;
+				timer.Stop();
+			}
 
 			process.Terminated -= Process_Terminated;
 		}