Re-implement Reload in the engine

src/NUnitEngine/nunit.engine.tests/Runners/MasterTestRunnerTests.cs

@@ -208,6 +208,36 @@ public void Run()
             CheckTestRunEvents();
         }
 
+        [Test]
+        public void RunAfterReload()
+        {
+            // Engine issue #609
+            _runner.Load();
+            _runner.Reload();
+            var result = _runner.Run(this, TestFilter.Empty);
+
+            Assert.That(result.Name, Is.EqualTo("test-run"));
+            CheckTestRunResult(result, _testRunData);
+
+            CheckThatIdsAreUnique(result);
+
+            CheckTestRunEvents();
+        }
+
+        [Test]
+        public void ExploreAfterReload()
+        {
+            // Engine issue #609
+            _runner.Load();
+            _runner.Reload();
+            var result = _runner.Explore(TestFilter.Empty);
+
+            Assert.That(result.Name, Is.EqualTo("test-run"));
+            CheckResult(result, _testRunData);
+
+            CheckThatIdsAreUnique(result);
+        }
+
 #if !NETCOREAPP1_1
         [Test]
         public void RunAsync()

src/NUnitEngine/nunit.engine/Runners/AbstractTestRunner.cs

@@ -80,14 +80,10 @@ public bool IsPackageLoaded
         protected abstract TestEngineResult LoadPackage();
 
         /// <summary>
-        /// Reload the currently loaded test package. Overridden
-        /// in derived classes to take any additional action.
+        /// Reload the currently loaded test package.
         /// </summary>
         /// <returns>A TestEngineResult.</returns>
-        protected virtual TestEngineResult ReloadPackage()
-        {
-            return LoadPackage();
-        }
+        protected abstract TestEngineResult ReloadPackage();
 
         /// <summary>
         /// Unload any loaded TestPackage. Overridden in

src/NUnitEngine/nunit.engine/Runners/AggregatingTestRunner.cs

@@ -122,6 +122,20 @@ protected override TestEngineResult LoadPackage()
             return ResultHelper.Merge(results);
         }
 
+        /// <summary>
+        /// Reload the currently loaded test package.
+        /// </summary>
+        /// <returns>A TestEngineResult.</returns>
+        protected override TestEngineResult ReloadPackage()
+        {
+            var results = new List<TestEngineResult>();
+
+            foreach (var runner in Runners)
+                results.Add(runner.Reload());
+
+            return ResultHelper.Merge(results);
+        }
+
         /// <summary>
         /// Unload any loaded TestPackages.
         /// </summary>

src/NUnitEngine/nunit.engine/Runners/DirectTestRunner.cs

@@ -157,6 +157,21 @@ protected override TestEngineResult LoadPackage()
             return result;
         }
 
+        protected override TestEngineResult ReloadPackage()
+        {
+            var result = new TestEngineResult();
+            var packages = TestPackage.Select(p => !p.HasSubPackages());
+
+            int index = 0;
+            foreach (IFrameworkDriver driver in _drivers)
+            {
+                var package = packages[index++];
+                result.Add(driver.Load(package.FullName, package.Settings));
+            }
+
+            return result;
+        }
+
         private static string LoadDriver(IFrameworkDriver driver, string testFile, TestPackage subPackage)
         {
             try

src/NUnitEngine/nunit.engine/Runners/ProcessRunner.cs

@@ -109,6 +109,17 @@ protected override TestEngineResult LoadPackage()
             }
         }
 
+        /// <summary>
+        /// Reload the currently loaded test package.
+        /// </summary>
+        /// <returns>A TestEngineResult.</returns>
+        protected override TestEngineResult ReloadPackage()
+        {
+            log.Info("Reloading " + TestPackage.Name);
+
+            return _remoteRunner.Reload();
+        }
+
         /// <summary>
         /// Unload any loaded TestPackage and clear
         /// the reference to the remote runner.