Index: Ringtoets/Integration/test/Ringtoets.Integration.Plugin.Test/RingtoetsPluginTest.cs
===================================================================
diff -u -r50b203a8d5c805fc548fb6b92c70a847190da6a5 -r2227f1d3a31b15a6d05c5385898d5da4b79dcdea
--- Ringtoets/Integration/test/Ringtoets.Integration.Plugin.Test/RingtoetsPluginTest.cs	(.../RingtoetsPluginTest.cs)	(revision 50b203a8d5c805fc548fb6b92c70a847190da6a5)
+++ Ringtoets/Integration/test/Ringtoets.Integration.Plugin.Test/RingtoetsPluginTest.cs	(.../RingtoetsPluginTest.cs)	(revision 2227f1d3a31b15a6d05c5385898d5da4b79dcdea)
@@ -30,6 +30,7 @@
 using Core.Common.Gui;
 using Core.Common.Gui.ContextMenu;
 using Core.Common.Gui.Forms.MainWindow;
+using Core.Common.Gui.Forms.ViewHost;
 using Core.Common.Gui.Plugin;
 using Core.Common.Gui.Settings;
 using Core.Common.TestUtil;
@@ -452,5 +453,47 @@
                 Assert.AreEqual(1, importers.Count(i => i is FailureMechanismSectionsImporter));
             }
         }
+
+        [Test]
+        public void Activate_WithoutGui_ThrowsInvalidOperationException()
+        {
+            // Setup
+            using (var plugin = new RingtoetsPlugin())
+            {
+                // Call
+                TestDelegate test = () => plugin.Activate();
+
+                // Assert
+                Assert.Throws<InvalidOperationException>(test);
+            }
+        }
+        
+        [Test]
+        public void Activate_WithGui_DoesNotThrowException()
+        {
+            // Setup
+            var mockRepository = new MockRepository();
+            var mainWindowMock = mockRepository.StrictMock<IMainWindow>();
+            var documentViewControllerMock = mockRepository.StrictMock<IDocumentViewController>();
+            var guiMock = mockRepository.StrictMock<IGui>();
+            guiMock.Expect(g => g.MainWindow).Return(mainWindowMock);
+            guiMock.Expect(g => g.DocumentViewController).Return(documentViewControllerMock);
+            guiMock.Expect(g => g.ProjectOpened += null).IgnoreArguments();
+            guiMock.Stub(g => g.ProjectOpened -= null).IgnoreArguments();
+            mockRepository.ReplayAll();
+
+            using (var plugin = new RingtoetsPlugin())
+            {
+                plugin.Gui = guiMock;
+
+                // Call
+                TestDelegate test = () => plugin.Activate();
+
+                // Assert
+                Assert.DoesNotThrow(test);
+            }
+
+            mockRepository.VerifyAll();
+        }
     }
 }
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