Only invalidate test results if the code of the unit test has changed. Closes #4705

Author: comintern

Rubberduck.Core/UI/UnitTesting/TestExplorerModel.cs

@@ -13,16 +13,16 @@ internal class TestExplorerModel : ViewModelBase, IDisposable
     {
         private readonly IVBE _vbe;
         private readonly Dispatcher _dispatcher;
-        private readonly ITestEngine testEngine;
+        private readonly ITestEngine _testEngine;
 
         public TestExplorerModel(IVBE vbe, ITestEngine testEngine)
         {
             _vbe = vbe;
-            this.testEngine = testEngine;
+            _testEngine = testEngine;
 
-            testEngine.TestsRefreshed += HandleTestsRefreshed;
-            testEngine.TestRunCompleted += HandleRunCompletion;
-            testEngine.TestCompleted += HandleTestCompletion;
+            _testEngine.TestsRefreshed += HandleTestsRefreshed;
+            _testEngine.TestRunCompleted += HandleRunCompletion;
+            _testEngine.TestCompleted += HandleTestCompletion;
             _dispatcher = Dispatcher.CurrentDispatcher;
         }
 
@@ -52,17 +52,25 @@ private void HandleTestCompletion(object sender, TestCompletedEventArgs e)
 
         private void HandleTestsRefreshed(object sender, EventArgs args)
         {
+            var previous = Tests.ToList();
+            
             Tests.Clear();
-            foreach (var test in testEngine.Tests.Select(test => new TestMethodViewModel(test)))
+            foreach (var test in _testEngine.Tests)
             {
-                Tests.Add(test);
+                var adding = new TestMethodViewModel(test);
+                var match = previous.FirstOrDefault(ut => ut.Method.Equals(test));
+                if (match != null)
+                {
+                    adding.Result = match.Result;
+                }
+                Tests.Add(adding);
             }
             RefreshProgressBarColor();
         }
 
         private void RefreshProgressBarColor()
         {
-            var overallOutcome = testEngine.CurrentAggregateOutcome;
+            var overallOutcome = _testEngine.CurrentAggregateOutcome;
             switch (overallOutcome)
             {
                 case TestOutcome.Failed:
@@ -85,7 +93,8 @@ private void RefreshProgressBarColor()
         private long _totalDuration;
         public long TotalDuration
         {
-            get { return _totalDuration; } private set
+            get => _totalDuration;
+            private set
             {
                 _totalDuration = value;
                 OnPropertyChanged();
@@ -127,11 +136,11 @@ public bool IsBusy
 
         public void Dispose()
         {
-            if (testEngine != null)
+            if (_testEngine != null)
             {
-                testEngine.TestCompleted -= HandleTestCompletion;
-                testEngine.TestsRefreshed -= HandleTestsRefreshed;
-                testEngine.TestRunCompleted -= HandleRunCompletion;
+                _testEngine.TestCompleted -= HandleTestCompletion;
+                _testEngine.TestsRefreshed -= HandleTestsRefreshed;
+                _testEngine.TestRunCompleted -= HandleRunCompletion;
             }
         }
     }

Rubberduck.Core/UI/UnitTesting/TestExplorerViewModel.cs

@@ -82,6 +82,7 @@ private void TestEngineTestCompleted(object sender, TestCompletedEventArgs e)
         {
             // Propagate the event
             TestCompleted?.Invoke(sender, e);
+            Tests.Refresh();
         }
 
         public INavigateSource SelectedItem => SelectedTest;

Rubberduck.Core/UI/UnitTesting/ViewModels/TestMethodViewModel.cs

@@ -1,7 +1,6 @@
 using Rubberduck.Interaction.Navigation;
 using Rubberduck.UnitTesting;
 using Rubberduck.VBEditor;
-using System.Collections.Generic;
 
 namespace Rubberduck.UI.UnitTesting.ViewModels
 {
@@ -12,7 +11,7 @@ public TestMethodViewModel(TestMethod test)
             Method = test;
         }
 
-        public TestMethod Method { get; private set; }
+        public TestMethod Method { get; }
 
         private TestResult _result = new TestResult(TestOutcome.Unknown);
 

Rubberduck.UnitTesting/UnitTesting/TestMethod.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Rubberduck.Parsing;
 using Rubberduck.Parsing.Annotations;
@@ -10,15 +9,17 @@
 
 namespace Rubberduck.UnitTesting
 {
-    [SuppressMessage("ReSharper", "ExplicitCallerInfoArgument")]
     public class TestMethod : IEquatable<TestMethod>, INavigateSource
     {
         public TestMethod(Declaration declaration)
         {
             Declaration = declaration;
+            TestCode = declaration.Context.GetText();
         }
         public Declaration Declaration { get; }
 
+        public string TestCode { get; }
+
         public TestCategory Category
         {
             get
@@ -36,8 +37,10 @@ public NavigateCodeEventArgs GetNavigationArgs()
             return new NavigateCodeEventArgs(new QualifiedSelection(Declaration.QualifiedName.QualifiedModuleName, Declaration.Context.GetSelection()));
         }
 
-        public bool Equals(TestMethod other) => other != null && Declaration.QualifiedName.Equals(other.Declaration.QualifiedName);
+        public bool Equals(TestMethod other) => other != null && Declaration.QualifiedName.Equals(other.Declaration.QualifiedName) && TestCode.Equals(other.TestCode);
+
         public override bool Equals(object obj) => obj is TestMethod method && Equals(method);
+
         public override int GetHashCode() => Declaration.QualifiedName.GetHashCode();
     }
 }