PowerShell · iSazonov · Nov 5, 2020 · Jul 27, 2020 · Aug 10, 2020
diff --git a/src/Microsoft.Management.Infrastructure.CimCmdlets/CimAsyncOperation.cs b/src/Microsoft.Management.Infrastructure.CimCmdlets/CimAsyncOperation.cs
@@ -388,8 +388,7 @@ protected object GetReferenceOrReferenceArrayObject(object value, ref CimType re
             if (cimReference != null)
             {
                 object baseObject = GetBaseObject(cimReference.Value);
-                CimInstance cimInstance = baseObject as CimInstance;
-                if (cimInstance == null)
+                if (!(baseObject is CimInstance cimInstance))
                 {
                     return null;
                 }
@@ -412,8 +411,7 @@ protected object GetReferenceOrReferenceArrayObject(object value, ref CimType re
                 CimInstance[] cimInstanceArray = new CimInstance[cimReferenceArray.Length];
                 for (int i = 0; i < cimReferenceArray.Length; i++)
                 {
-                    PSReference tempCimReference = cimReferenceArray[i] as PSReference;
-                    if (tempCimReference == null)
+                    if (!(cimReferenceArray[i] is PSReference tempCimReference))
                     {
                         return null;
                     }

diff --git a/src/Microsoft.Management.Infrastructure.CimCmdlets/CimSessionProxy.cs b/src/Microsoft.Management.Infrastructure.CimCmdlets/CimSessionProxy.cs
@@ -2085,8 +2085,7 @@ protected override bool PreNewActionEvent(CmdletActionEventArgs args)
             }
 
             CimWriteResultObject writeResultObject = args.Action as CimWriteResultObject;
-            CimClass cimClass = writeResultObject.Result as CimClass;
-            if (cimClass == null)
+            if (!(writeResultObject.Result is CimClass cimClass))
             {
                 return true;
             }
@@ -2239,8 +2238,7 @@ protected override bool PreNewActionEvent(CmdletActionEventArgs args)
             }
 
             CimWriteResultObject writeResultObject = args.Action as CimWriteResultObject;
-            CimInstance cimInstance = writeResultObject.Result as CimInstance;
-            if (cimInstance == null)
+            if (!(writeResultObject.Result is CimInstance cimInstance))
             {
                 return true;
             }

diff --git a/src/Microsoft.PowerShell.Commands.Management/cimSupport/cmdletization/cim/cimChildJobBase.cs b/src/Microsoft.PowerShell.Commands.Management/cimSupport/cmdletization/cim/cimChildJobBase.cs
@@ -84,8 +84,7 @@ private enum WsManErrorCode : uint
 
         private static bool IsWsManQuotaReached(Exception exception)
         {
-            var cimException = exception as CimException;
-            if (cimException == null)
+            if (!(exception is CimException cimException))
             {
                 return false;
             }
@@ -1010,8 +1009,7 @@ private CimResponseType PromptUserCallback(string message, CimPromptType promptT
         internal static bool IsShowComputerNameMarkerPresent(CimInstance cimInstance)
         {
             PSObject pso = PSObject.AsPSObject(cimInstance);
-            PSPropertyInfo psShowComputerNameProperty = pso.InstanceMembers[RemotingConstants.ShowComputerNameNoteProperty] as PSPropertyInfo;
-            if (psShowComputerNameProperty == null)
+            if (!(pso.InstanceMembers[RemotingConstants.ShowComputerNameNoteProperty] is PSPropertyInfo psShowComputerNameProperty))
             {
                 return false;
             }

diff --git a/src/Microsoft.PowerShell.Commands.Management/cimSupport/cmdletization/cim/cimWrapper.cs b/src/Microsoft.PowerShell.Commands.Management/cimSupport/cmdletization/cim/cimWrapper.cs
@@ -172,8 +172,7 @@ private CimJobContext CreateJobContext(CimSession session, object targetObject)
         /// <returns><see cref="System.Management.Automation.Job"/> object that performs a query against the wrapped object model.</returns>
         internal override StartableJob CreateQueryJob(CimSession session, QueryBuilder baseQuery)
         {
-            CimQuery query = baseQuery as CimQuery;
-            if (query == null)
+            if (!(baseQuery is CimQuery query))
             {
                 throw new ArgumentNullException(nameof(baseQuery));
             }

diff --git a/src/Microsoft.PowerShell.Commands.Management/cimSupport/cmdletization/cim/clientSideQuery.cs b/src/Microsoft.PowerShell.Commands.Management/cimSupport/cmdletization/cim/clientSideQuery.cs
@@ -572,8 +572,7 @@ private static bool ActualValueGreaterThanOrEqualToExpectedValue(string property
             {
                 try
                 {
-                    var expectedComparable = expectedPropertyValue as IComparable;
-                    if (expectedComparable == null)
+                    if (!(expectedPropertyValue is IComparable expectedComparable))
                     {
                         return false;
                     }
@@ -608,8 +607,7 @@ private static bool ActualValueLessThanOrEqualToExpectedValue(string propertyNam
             {
                 try
                 {
-                    var actualComparable = actualPropertyValue as IComparable;
-                    if (actualComparable == null)
+                    if (!(actualPropertyValue is IComparable actualComparable))
                     {
                         return false;
                     }

diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CustomSerialization.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CustomSerialization.cs
@@ -710,8 +710,7 @@ private void WriteMemberInfoCollection(
                     continue;
                 }
 
-                PSPropertyInfo property = info as PSPropertyInfo;
-                if (property == null)
+                if (!(info is PSPropertyInfo property))
                 {
                     continue;
                 }

diff --git a/...ft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ColumnInfo.cs b/...ft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ColumnInfo.cs
@@ -48,8 +48,7 @@ internal Type GetValueType(PSObject liveObject, out object columnValue)
         /// <returns>The source string limited in the number of lines.</returns>
         internal static object LimitString(object src)
         {
-            string srcString = src as string;
-            if (srcString == null)
+            if (!(src is string srcString))
             {
                 return src;
             }

diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Get-PSBreakpoint.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Get-PSBreakpoint.cs
@@ -120,9 +120,7 @@ protected override void ProcessRecord()
                     Command,
                     delegate (Breakpoint breakpoint, string command)
                     {
-                        CommandBreakpoint commandBreakpoint = breakpoint as CommandBreakpoint;
-
-                        if (commandBreakpoint == null)
+                        if (!(breakpoint is CommandBreakpoint commandBreakpoint))
                         {
                             return false;
                         }
@@ -137,9 +135,7 @@ protected override void ProcessRecord()
                     Variable,
                     delegate (Breakpoint breakpoint, string variable)
                     {
-                        VariableBreakpoint variableBreakpoint = breakpoint as VariableBreakpoint;
-
-                        if (variableBreakpoint == null)
+                        if (!(breakpoint is VariableBreakpoint variableBreakpoint))
                         {
                             return false;
                         }

diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ImplicitRemotingCommands.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ImplicitRemotingCommands.cs
@@ -2623,8 +2623,7 @@ private string GenerateConnectionStringForNewRunspace()
 
         private string GenerateAllowRedirectionParameter()
         {
-            WSManConnectionInfo wsmanConnectionInfo = _remoteRunspaceInfo.Runspace.ConnectionInfo as WSManConnectionInfo;
-            if (wsmanConnectionInfo == null)
+            if (!(_remoteRunspaceInfo.Runspace.ConnectionInfo is WSManConnectionInfo wsmanConnectionInfo))
             {
                 return string.Empty;
             }
@@ -2650,8 +2649,7 @@ private string GenerateAuthenticationMechanismParameter()
                 return string.Empty;
             }
 
-            WSManConnectionInfo wsmanConnectionInfo = _remoteRunspaceInfo.Runspace.ConnectionInfo as WSManConnectionInfo;
-            if (wsmanConnectionInfo == null)
+            if (!(_remoteRunspaceInfo.Runspace.ConnectionInfo is WSManConnectionInfo wsmanConnectionInfo))
             {
                 return string.Empty;
             }

diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ObjectCommandComparer.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ObjectCommandComparer.cs
@@ -77,8 +77,7 @@ internal CultureInfo Culture
         /// <returns>True if both the objects are same or else returns false.</returns>
         public override bool Equals(object inputObject)
         {
-            ObjectCommandPropertyValue objectCommandPropertyValueObject = inputObject as ObjectCommandPropertyValue;
-            if (objectCommandPropertyValueObject == null)
+            if (!(inputObject is ObjectCommandPropertyValue objectCommandPropertyValueObject))
             {
                 return false;
             }

diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/OrderObjectBase.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/OrderObjectBase.cs
@@ -358,9 +358,7 @@ internal static string[] GetDefaultKeyPropertySet(PSObject mshObj)
                 return null;
             }
 
-            PSPropertySet defaultKeys = standardNames.Members["DefaultKeyPropertySet"] as PSPropertySet;
-
-            if (defaultKeys == null)
+            if (!(standardNames.Members["DefaultKeyPropertySet"] is PSPropertySet defaultKeys))
             {
                 return null;
             }

diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/JsonObject.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/JsonObject.cs
@@ -633,9 +633,7 @@ private static object ProcessValue(object obj, int currentDepth, in ConvertToJso
         /// </returns>
         private static object AddPsProperties(object psObj, object obj, int depth, bool isPurePSObj, bool isCustomObj, in ConvertToJsonContext context)
         {
-            PSObject pso = psObj as PSObject;
-
-            if (pso == null)
+            if (!(psObj is PSObject pso))
             {
                 return obj;
             }

diff --git a/src/Microsoft.PowerShell.Security/security/AclCommands.cs b/src/Microsoft.PowerShell.Security/security/AclCommands.cs
@@ -208,8 +208,7 @@ public static string GetOwner(PSObject instance)
                 throw PSTraceSource.NewArgumentNullException(nameof(instance));
             }
 
-            ObjectSecurity sd = instance.BaseObject as ObjectSecurity;
-            if (sd == null)
+            if (!(instance.BaseObject is ObjectSecurity sd))
             {
                 throw PSTraceSource.NewArgumentNullException(nameof(instance));
             }
@@ -248,8 +247,7 @@ public static string GetGroup(PSObject instance)
                 throw PSTraceSource.NewArgumentNullException(nameof(instance));
             }
 
-            ObjectSecurity sd = instance.BaseObject as ObjectSecurity;
-            if (sd == null)
+            if (!(instance.BaseObject is ObjectSecurity sd))
             {
                 throw PSTraceSource.NewArgumentNullException(nameof(instance));
             }
@@ -588,8 +586,7 @@ public static string GetSddl(PSObject instance)
                 throw PSTraceSource.NewArgumentNullException(nameof(instance));
             }
 
-            ObjectSecurity sd = instance.BaseObject as ObjectSecurity;
-            if (sd == null)
+            if (!(instance.BaseObject is ObjectSecurity sd))
             {
                 throw PSTraceSource.NewArgumentNullException(nameof(instance));
             }

diff --git a/src/System.Management.Automation/FormatAndOutput/common/DisplayDatabase/typeDataQuery.cs b/src/System.Management.Automation/FormatAndOutput/common/DisplayDatabase/typeDataQuery.cs
@@ -602,9 +602,7 @@ internal static AppliesTo GetAllApplicableTypes(TypeInfoDataBase db, AppliesTo a
                 else
                 {
                     // check if we have a type group reference
-                    TypeGroupReference tgr = r as TypeGroupReference;
-
-                    if (tgr == null)
+                    if (!(r is TypeGroupReference tgr))
                         continue;
 
                     // find the type group definition the reference points to

diff --git a/src/System.Management.Automation/FormatAndOutput/common/FormattingObjectsDeserializer.cs b/src/System.Management.Automation/FormatAndOutput/common/FormattingObjectsDeserializer.cs
@@ -55,9 +55,7 @@ fid is GroupEndData ||
                 return false;
             }
 
-            string classId = GetProperty(so, FormatInfoData.classidProperty) as string;
-
-            if (classId == null)
+            if (!(GetProperty(so, FormatInfoData.classidProperty) is string classId))
             {
                 // it's not one of the objects derived from FormatInfoData
                 return false;
@@ -113,9 +111,7 @@ fid is GroupEndData ||
                 return so;
             }
 
-            string classId = GetProperty(so, FormatInfoData.classidProperty) as string;
-
-            if (classId == null)
+            if (!(GetProperty(so, FormatInfoData.classidProperty) is string classId))
             {
                 // it's not one of the objects derived from FormatInfoData,
                 // just return it as is

diff --git a/src/System.Management.Automation/cimSupport/other/ciminstancetypeadapter.cs b/src/System.Management.Automation/cimSupport/other/ciminstancetypeadapter.cs
@@ -285,8 +285,7 @@ private List<CimClass> GetInheritanceChain(CimInstance cimInstance)
         /// <returns></returns>
         public override Collection<string> GetTypeNameHierarchy(object baseObject)
         {
-            var cimInstance = baseObject as CimInstance;
-            if (cimInstance == null)
+            if (!(baseObject is CimInstance cimInstance))
             {
                 throw new ArgumentNullException(nameof(baseObject));
             }
@@ -362,8 +361,7 @@ public override bool IsSettable(PSAdaptedProperty adaptedProperty)
                 return false;
             }
 
-            CimProperty cimProperty = adaptedProperty.Tag as CimProperty;
-            if (cimProperty == null)
+            if (!(adaptedProperty.Tag is CimProperty cimProperty))
             {
                 return false;
             }

diff --git a/src/System.Management.Automation/engine/ArgumentTypeConverterAttribute.cs b/src/System.Management.Automation/engine/ArgumentTypeConverterAttribute.cs
@@ -67,9 +67,7 @@ internal object Transform(EngineIntrinsics engineIntrinsics, object inputData, b
                             else
                                 temp = result;
 
-                            PSReference reference = temp as PSReference;
-
-                            if (reference == null)
+                            if (!(temp is PSReference reference))
                             {
                                 throw new PSInvalidCastException("InvalidCastExceptionReferenceTypeExpected", null,
                                                                    ExtendedTypeSystem.ReferenceTypeExpected);

diff --git a/src/System.Management.Automation/engine/Attributes.cs b/src/System.Management.Automation/engine/Attributes.cs
@@ -839,8 +839,7 @@ public sealed class ValidateLengthAttribute : ValidateEnumeratedArgumentsAttribu
         /// <exception cref="ArgumentException">For invalid arguments.</exception>
         protected override void ValidateElement(object element)
         {
-            string objectString = element as string;
-            if (objectString == null)
+            if (!(element is string objectString))
             {
                 throw new ValidationMetadataException(
                     "ValidateLengthNotString",
@@ -1857,8 +1856,7 @@ protected override void Validate(object arguments, EngineIntrinsics engineIntrin
                     Metadata.ValidateNotNullFailure);
             }
 
-            var path = arguments as string;
-            if (path == null)
+            if (!(arguments is string path))
             {
                 throw new ValidationMetadataException(
                     "PathArgumentIsNotValid",

diff --git a/src/System.Management.Automation/engine/CmdletParameterBinderController.cs b/src/System.Management.Automation/engine/CmdletParameterBinderController.cs
@@ -626,8 +626,7 @@ private Dictionary<MergedCompiledCommandParameter, object> GetDefaultParameterVa
 
             foreach (DictionaryEntry entry in DefaultParameterValues)
             {
-                string key = entry.Key as string;
-                if (key == null)
+                if (!(entry.Key is string key))
                 {
                     continue;
                 }
@@ -4389,8 +4388,7 @@ public override bool ContainsKey(object key)
                 throw PSTraceSource.NewArgumentNullException(nameof(key));
             }
 
-            var strKey = key as string;
-            if (strKey == null) { return false; }
+            if (!(key is string strKey)) { return false; }
 
             string keyAfterTrim = strKey.Trim();
             return base.ContainsKey(keyAfterTrim);
@@ -4416,8 +4414,7 @@ private void AddImpl(object key, object value, bool isSelfIndexing)
                 throw PSTraceSource.NewArgumentNullException(nameof(key));
             }
 
-            var strKey = key as string;
-            if (strKey == null)
+            if (!(key is string strKey))
             {
                 throw PSTraceSource.NewArgumentException(nameof(key), ParameterBinderStrings.StringValueKeyExpected, key, key.GetType().FullName);
             }
@@ -4462,8 +4459,7 @@ public override object this[object key]
             {
                 if (key == null) { throw PSTraceSource.NewArgumentNullException(nameof(key)); }
 
-                var strKey = key as string;
-                if (strKey == null) { return null; }
+                if (!(key is string strKey)) { return null; }
 
                 string keyAfterTrim = strKey.Trim();
                 return base[keyAfterTrim];
@@ -4486,8 +4482,7 @@ public override void Remove(object key)
                 throw PSTraceSource.NewArgumentNullException(nameof(key));
             }
 
-            var strKey = key as string;
-            if (strKey == null) { return; }
+            if (!(key is string strKey)) { return; }
 
             string keyAfterTrim = strKey.Trim();
             if (base.ContainsKey(keyAfterTrim))

diff --git a/src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs b/src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs
@@ -239,8 +239,7 @@ private static bool CompleteAgainstSwitchFile(Ast lastAst, Token tokenBeforeCurs
             if (lastAst.Parent is CommandExpressionAst)
             {
                 // Handle "switch -file m<tab>" or "switch -file *.ps1<tab>"
-                var pipeline = lastAst.Parent.Parent as PipelineAst;
-                if (pipeline == null)
+                if (!(lastAst.Parent.Parent is PipelineAst pipeline))
                 {
                     return false;
                 }