remove some redundant assignments

src/Microsoft.TestPlatform.Common/ExtensionFramework/TestPluginCache.cs

@@ -128,7 +128,7 @@ public List<string> GetExtensionPaths(string endsWithPattern, bool skipDefaultEx
             return TestExtensions.GetTestExtensionCache<TPluginInfo>();
         }
 
-        Dictionary<string, TPluginInfo>? pluginInfos = null;
+        Dictionary<string, TPluginInfo>? pluginInfos;
         SetupAssemblyResolver(null);
 
         // Some times TestPlatform.core.dll assembly fails to load in the current appdomain (from devenv.exe).
@@ -177,6 +177,7 @@ public List<string> GetExtensionPaths(string endsWithPattern, bool skipDefaultEx
             // Nothing to do here, we just do not want to do an EqtTrace.Fail for this thread
             // being aborted as it is a legitimate exception to receive.
             EqtTrace.Verbose("TestPluginCache.DiscoverTestExtensions: Data extension discovery is being aborted due to a thread abort.");
+            return null;
         }
 #endif
         catch (Exception e)

src/Microsoft.TestPlatform.Common/ExtensionFramework/TestPluginDiscoverer.cs

@@ -91,9 +91,8 @@ private static void GetTestExtensionsFromFiles<TPluginInfo, TExtension>(
             }
             try
             {
-                Assembly? assembly = null;
                 var assemblyName = Path.GetFileNameWithoutExtension(file);
-                assembly = Assembly.Load(new AssemblyName(assemblyName));
+                var assembly = Assembly.Load(new AssemblyName(assemblyName));
                 if (assembly != null)
                 {
                     GetTestExtensionsFromAssembly<TPluginInfo, TExtension>(assembly, pluginInfos, file);

src/Microsoft.TestPlatform.Common/Filtering/FilterExpression.cs

@@ -130,8 +130,7 @@ private static void ProcessOperator(Stack<FilterExpression> filterStack, Operato
             // Only the leaves have a condition value.
             if (current._condition != null)
             {
-                bool valid = false;
-                valid = current._condition.ValidForProperties(properties, propertyProvider);
+                var valid = current._condition.ValidForProperties(properties, propertyProvider);
                 // If it's not valid will add it to the function's return array.
                 return !valid ? new string[1] { current._condition.Name } : null;
             }

src/Microsoft.TestPlatform.CrossPlatEngine/TestSession/ProxyTestSessionManager.cs

@@ -209,7 +209,7 @@ public virtual bool StartSession(ITestSessionEventsHandler eventsHandler, IReque
     /// <inheritdoc/>
     public virtual bool StopSession(IRequestData requestData)
     {
-        var testSessionId = string.Empty;
+        string testSessionId;
         lock (_lockObject)
         {
             if (_testSessionInfo == null)
@@ -251,7 +251,7 @@ public virtual bool StopSession(IRequestData requestData)
     /// <returns>The dequeued proxy.</returns>
     public virtual ProxyOperationManager DequeueProxy(string source, string? runSettings)
     {
-        ProxyOperationManagerContainer? proxyContainer = null;
+        ProxyOperationManagerContainer? proxyContainer;
 
         lock (_proxyOperationLockObject)
         {

src/Microsoft.TestPlatform.CrossPlatEngine/TestSession/TestSessionPool.cs

@@ -96,7 +96,7 @@ public virtual bool KillSession(TestSessionInfo testSessionInfo, IRequestData re
     {
         // TODO (copoiena): What happens if some request is running for the current session ?
         // Should we stop the request as well ? Probably yes.
-        IProxyTestSessionManager? proxyManager = null;
+        IProxyTestSessionManager? proxyManager;
 
         lock (_lockObject)
         {
@@ -133,7 +133,7 @@ public virtual bool KillSession(TestSessionInfo testSessionInfo, IRequestData re
     {
         ValidateArg.NotNull(requestData, nameof(requestData));
 
-        ProxyTestSessionManager? sessionManager = null;
+        ProxyTestSessionManager? sessionManager;
         lock (_lockObject)
         {
             if (!_sessionPool.ContainsKey(testSessionInfo))
@@ -181,7 +181,7 @@ public virtual bool KillSession(TestSessionInfo testSessionInfo, IRequestData re
     /// <returns>True if the operation succeeded, false otherwise.</returns>
     public virtual bool ReturnProxy(TestSessionInfo testSessionInfo, int proxyId)
     {
-        ProxyTestSessionManager? sessionManager = null;
+        ProxyTestSessionManager? sessionManager;
         lock (_lockObject)
         {
             if (!_sessionPool.ContainsKey(testSessionInfo))

src/Microsoft.TestPlatform.Extensions.BlameDataCollector/MiniDumpWriteDump.cs

@@ -28,8 +28,7 @@ public static void CollectDumpUsingMiniDumpWriteDump(Process process, string out
         using var stream = new FileStream(outputFile, FileMode.Create, FileAccess.ReadWrite, FileShare.None);
         NativeMethods.MinidumpExceptionInformation exceptionInfo = default;
 
-        NativeMethods.MinidumpType dumpType = NativeMethods.MinidumpType.MiniDumpNormal;
-        dumpType = type switch
+        var dumpType = type switch
         {
             MiniDumpTypeOption.Full => NativeMethods.MinidumpType.MiniDumpWithFullMemory |
                                        NativeMethods.MinidumpType.MiniDumpWithDataSegs |
@@ -39,12 +38,12 @@ public static void CollectDumpUsingMiniDumpWriteDump(Process process, string out
                                        NativeMethods.MinidumpType.MiniDumpWithThreadInfo |
                                        NativeMethods.MinidumpType.MiniDumpWithTokenInformation,
             MiniDumpTypeOption.WithHeap => NativeMethods.MinidumpType.MiniDumpWithPrivateReadWriteMemory |
-                                       NativeMethods.MinidumpType.MiniDumpWithDataSegs |
-                                       NativeMethods.MinidumpType.MiniDumpWithHandleData |
-                                       NativeMethods.MinidumpType.MiniDumpWithUnloadedModules |
-                                       NativeMethods.MinidumpType.MiniDumpWithFullMemoryInfo |
-                                       NativeMethods.MinidumpType.MiniDumpWithThreadInfo |
-                                       NativeMethods.MinidumpType.MiniDumpWithTokenInformation,
+                                           NativeMethods.MinidumpType.MiniDumpWithDataSegs |
+                                           NativeMethods.MinidumpType.MiniDumpWithHandleData |
+                                           NativeMethods.MinidumpType.MiniDumpWithUnloadedModules |
+                                           NativeMethods.MinidumpType.MiniDumpWithFullMemoryInfo |
+                                           NativeMethods.MinidumpType.MiniDumpWithThreadInfo |
+                                           NativeMethods.MinidumpType.MiniDumpWithTokenInformation,
             MiniDumpTypeOption.Mini => NativeMethods.MinidumpType.MiniDumpWithThreadInfo,
             _ => NativeMethods.MinidumpType.MiniDumpNormal,
         };

src/Microsoft.TestPlatform.ObjectModel/Navigation/FullSymbolReader.cs

@@ -309,7 +309,7 @@ private void PopulateCacheForTypeAndMethodSymbols()
         ValidateArg.NotNullOrEmpty(typeName, nameof(typeName));
 
         IDiaEnumSymbols? enumSymbols = null;
-        IDiaSymbol? typeSymbol = null;
+        IDiaSymbol? typeSymbol;
         IDiaSymbol? global = null;
 
         try
@@ -378,7 +378,7 @@ private void PopulateCacheForTypeAndMethodSymbols()
         ValidateArg.NotNullOrEmpty(methodName, nameof(methodName));
 
         IDiaEnumSymbols? enumSymbols = null;
-        IDiaSymbol? methodSymbol = null;
+        IDiaSymbol? methodSymbol;
         Dictionary<string, IDiaSymbol> methodSymbolsForType;
 
         try

src/Microsoft.TestPlatform.PlatformAbstractions/common/System/ProcessHelper.cs

@@ -67,7 +67,6 @@ public object LaunchProcess(string processPath, string? arguments, string? worki
         catch (Exception)
         {
             process.Dispose();
-            process = null;
 
             //EqtTrace.Error("TestHost Object {0} failed to launch with the following exception: {1}", processPath, exception.Message);
             throw;

src/vstest.console/CommandLine/Executor.cs

@@ -276,12 +276,11 @@ private int GetArgumentProcessors(string[] args, out List<IArgumentProcessor> pr
         processors.Sort((p1, p2) => Comparer<ArgumentProcessorPriority>.Default.Compare(p1.Metadata.Value.Priority, p2.Metadata.Value.Priority));
         foreach (var processor in processors)
         {
-            IArgumentExecutor? executorInstance;
             try
             {
                 // Ensure the instance is created.  Note that the Lazy not only instantiates
                 // the argument processor, but also initializes it.
-                executorInstance = processor.Executor?.Value;
+                var executorInstance = processor.Executor?.Value;
             }
             catch (Exception ex)
             {

src/vstest.console/Processors/Utilities/ArgumentProcessorFactory.cs

@@ -276,7 +276,7 @@ public static IArgumentProcessor WrapLazyProcessorToInitializeOnInstantiation(IA
         var processorExecutor = processor.Executor;
         var lazyArgumentProcessor = new Lazy<IArgumentExecutor>(() =>
         {
-            IArgumentExecutor? instance = null;
+            IArgumentExecutor? instance;
             try
             {
                 instance = processorExecutor!.Value;
@@ -317,7 +317,7 @@ private static IArgumentProcessor WrapLazyProcessorToInitializeOnInstantiation(
         var processorExecutor = processor.Executor;
         var lazyArgumentProcessor = new Lazy<IArgumentExecutor>(() =>
         {
-            IArgumentsExecutor? instance = null;
+            IArgumentsExecutor? instance;
             try
             {
                 instance = (IArgumentsExecutor)processorExecutor!.Value;

test/Intent/Runner.cs

@@ -33,7 +33,7 @@ public static void Run(IEnumerable<string> paths, IRunLogger logger)
         var methods = types.SelectMany(type => type.GetMethods().SkipExcluded()).ToList();
         var methodsWithOnly = methods.Where(m => m.GetCustomAttribute<OnlyAttribute>() != null).ToList();
 
-        var methodsToRun = new List<MethodInfo>();
+        List<MethodInfo> methodsToRun;
         if (typesWithOnly.Count > 0 || methodsWithOnly.Count > 0)
         {
             // Some types or methods are decorated with Only. Putting Only on a type should run all methods in

test/Microsoft.TestPlatform.Acceptance.IntegrationTests/Build.cs

@@ -103,7 +103,7 @@ private static void BuildTestAssetsCompatibility()
         // We use the same version properties for NET.Test.Sdk as for VSTestConsole, for now.
         foreach (var sdkPropertyName in vstestConsoleVersionProperties)
         {
-            string? netTestSdkVersion = null;
+            string? netTestSdkVersion;
             if (sdkPropertyName == "VSTestConsoleLatestVersion")
             {
                 netTestSdkVersion = IntegrationTestEnvironment.LatestLocallyBuiltNugetVersion;

test/Microsoft.TestPlatform.Acceptance.IntegrationTests/TranslationLayerTests/TargetFrameworkTestHostDemultiplexer.cs

@@ -83,7 +83,7 @@ private void ExecuteContainerInMultiHost(RunnerInfo runnerInfo, int expectedHost
         Assert.AreEqual(expectedHost == -1 ? 1 : expectedHost > 10 ? 10 : expectedHost, hosts.Length);
 
         List<string> tests = new();
-        int testsRunInsideHost = 0;
+        int testsRunInsideHost;
         foreach (var file in hosts)
         {
             testsRunInsideHost = 0;