PowerShell · daxian-dbw · Jul 11, 2023 · May 21, 2023 · Jul 10, 2023 · Jul 10, 2023
diff --git a/src/System.Management.Automation/FormatAndOutput/common/BaseFormattingCommandParameters.cs b/src/System.Management.Automation/FormatAndOutput/common/BaseFormattingCommandParameters.cs
@@ -176,15 +176,13 @@ internal override object Verify(object val,
 
             // need to check the type:
             // it can be a string or a script block
-            ScriptBlock sb = val as ScriptBlock;
-            if (sb != null)
+            if (val is ScriptBlock sb)
             {
                 PSPropertyExpression ex = new PSPropertyExpression(sb);
                 return ex;
             }
 
-            string s = val as string;
-            if (s != null)
+            if (val is string s)
             {
                 if (string.IsNullOrEmpty(s))
                 {

diff --git a/src/System.Management.Automation/FormatAndOutput/common/BaseOutputtingCommand.cs b/src/System.Management.Automation/FormatAndOutput/common/BaseOutputtingCommand.cs
@@ -131,9 +131,7 @@ private bool ProcessObject(PSObject so)
             _cache ??= new FormattedObjectsCache(this.LineOutput.RequiresBuffering);
 
             // no need for formatting, just process the object
-            FormatStartData formatStart = o as FormatStartData;
-
-            if (formatStart != null)
+            if (o is FormatStartData formatStart)
             {
                 // get autosize flag from object
                 // turn on group caching
@@ -145,8 +143,7 @@ private bool ProcessObject(PSObject so)
                 else
                 {
                     // If the format info doesn't define column widths, then auto-size based on the first ten elements
-                    TableHeaderInfo headerInfo = formatStart.shapeInfo as TableHeaderInfo;
-                    if ((headerInfo != null) &&
+                    if ((formatStart.shapeInfo is TableHeaderInfo headerInfo) &&
                         (headerInfo.tableColumnInfoList.Count > 0) &&
                         (headerInfo.tableColumnInfoList[0].width == 0))
                     {
@@ -258,8 +255,7 @@ private enum PreprocessingState { raw, processed, error }
         /// <returns>Whether the object needs to be shunted to preprocessing.</returns>
         private bool NeedsPreprocessing(object o)
         {
-            FormatEntryData fed = o as FormatEntryData;
-            if (fed != null)
+            if (o is FormatEntryData fed)
             {
                 // we got an already pre-processed object
                 if (!fed.outOfBand)
@@ -322,8 +318,7 @@ private void ValidateCurrentFormattingState(FormattingState expectedFormattingSt
                 // need to abort the command
 
                 string violatingCommand = "format-*";
-                StartData sdObj = obj as StartData;
-                if (sdObj != null)
+                if (obj is StartData sdObj)
                 {
                     if (sdObj.shapeInfo is WideViewHeaderInfo)
                     {
@@ -383,18 +378,16 @@ private FormatMessagesContextManager.OutputContext CreateOutputContext(
                                         FormatMessagesContextManager.OutputContext parentContext,
                                         FormatInfoData formatInfoData)
         {
-            FormatStartData formatStartData = formatInfoData as FormatStartData;
             // initialize the format context
-            if (formatStartData != null)
+            if (formatInfoData is FormatStartData formatStartData)
             {
                 FormatOutputContext foc = new FormatOutputContext(parentContext, formatStartData);
 
                 return foc;
             }
 
-            GroupStartData gsd = formatInfoData as GroupStartData;
             // we are starting a group, initialize the group context
-            if (gsd != null)
+            if (formatInfoData is GroupStartData gsd)
             {
                 GroupOutputContext goc = null;
 
@@ -544,8 +537,7 @@ private void ProcessPayload(FormatEntryData fed, FormatMessagesContextManager.Ou
         private void ProcessOutOfBandPayload(FormatEntryData fed)
         {
             // try if it is raw text
-            RawTextFormatEntry rte = fed.formatEntryInfo as RawTextFormatEntry;
-            if (rte != null)
+            if (fed.formatEntryInfo is RawTextFormatEntry rte)
             {
                 if (fed.isHelpObject)
                 {
@@ -564,8 +556,7 @@ private void ProcessOutOfBandPayload(FormatEntryData fed)
             }
 
             // try if it is a complex entry
-            ComplexViewEntry cve = fed.formatEntryInfo as ComplexViewEntry;
-            if (cve != null && cve.formatValueList != null)
+            if (fed.formatEntryInfo is ComplexViewEntry cve && cve.formatValueList != null)
             {
                 ComplexWriter complexWriter = new ComplexWriter();
 
@@ -575,8 +566,7 @@ private void ProcessOutOfBandPayload(FormatEntryData fed)
                 return;
             }
             // try if it is a list view
-            ListViewEntry lve = fed.formatEntryInfo as ListViewEntry;
-            if (lve != null && lve.listViewFieldList != null)
+            if (fed.formatEntryInfo is ListViewEntry lve && lve.listViewFieldList != null)
             {
                 ListWriter listWriter = new ListWriter();
 
@@ -628,9 +618,7 @@ private FormatOutputContext FormatContext
             {
                 for (FormatMessagesContextManager.OutputContext oc = _ctxManager.ActiveOutputContext; oc != null; oc = oc.ParentContext)
                 {
-                    FormatOutputContext foc = oc as FormatOutputContext;
-
-                    if (foc != null)
+                    if (oc is FormatOutputContext foc)
                         return foc;
                 }
 
@@ -655,17 +643,13 @@ private void ProcessCachedGroup(FormatStartData formatStartData, List<PacketInfo
         {
             _formattingHint = null;
 
-            TableHeaderInfo thi = formatStartData.shapeInfo as TableHeaderInfo;
-
-            if (thi != null)
+            if (formatStartData.shapeInfo is TableHeaderInfo thi)
             {
                 ProcessCachedGroupOnTable(thi, objects);
                 return;
             }
 
-            WideViewHeaderInfo wvhi = formatStartData.shapeInfo as WideViewHeaderInfo;
-
-            if (wvhi != null)
+            if (formatStartData.shapeInfo is WideViewHeaderInfo wvhi)
             {
                 ProcessCachedGroupOnWide(wvhi, objects);
                 return;
@@ -982,11 +966,10 @@ internal TableOutputContext(OutCommandInner cmd,
             /// </summary>
             internal override void Initialize()
             {
-                TableFormattingHint tableHint = this.InnerCommand.RetrieveFormattingHint() as TableFormattingHint;
                 int[] columnWidthsHint = null;
-                // We expect that console width is less then 120.
+                // We expect that console width is less than 120.
 
-                if (tableHint != null)
+                if (this.InnerCommand.RetrieveFormattingHint() is TableFormattingHint tableHint)
                 {
                     columnWidthsHint = tableHint.columnWidths;
                 }
@@ -1215,13 +1198,11 @@ internal override void Initialize()
                 // set the hard wider default, to be used if no other info is available
                 int itemsPerRow = 2;
 
-                // get the header info and the view hint
-                WideFormattingHint hint = this.InnerCommand.RetrieveFormattingHint() as WideFormattingHint;
-
+                // get the header info
                 int columnsOnTheScreen = GetConsoleWindowWidth(this.InnerCommand._lo.ColumnNumber);
 
                 // give a preference to the hint, if there
-                if (hint != null && hint.maxWidth > 0)
+                if (this.InnerCommand.RetrieveFormattingHint() is WideFormattingHint hint && hint.maxWidth > 0)
                 {
                     itemsPerRow = TableWriter.ComputeWideViewBestItemsPerRowFit(hint.maxWidth, columnsOnTheScreen);
                 }
@@ -1402,10 +1383,10 @@ internal override void Initialize()
             /// <param name="fed">FormatEntryData to process.</param>
             internal override void ProcessPayload(FormatEntryData fed)
             {
-                ComplexViewEntry cve = fed.formatEntryInfo as ComplexViewEntry;
-                if (cve == null || cve.formatValueList == null)
-                    return;
-                _writer.WriteObject(cve.formatValueList);
+                if (fed.formatEntryInfo is ComplexViewEntry cve && cve.formatValueList is not null)
+                {
+                    _writer.WriteObject(cve.formatValueList);
+                }
             }
 
             private readonly ComplexWriter _writer = new ComplexWriter();

diff --git a/src/System.Management.Automation/FormatAndOutput/common/ComplexWriter.cs b/src/System.Management.Automation/FormatAndOutput/common/ComplexWriter.cs
@@ -70,8 +70,7 @@ private void GenerateFormatEntryDisplay(FormatEntry fe, int currentDepth)
         {
             foreach (object obj in fe.formatValueList)
             {
-                FormatEntry feChild = obj as FormatEntry;
-                if (feChild != null)
+                if (obj is FormatEntry feChild)
                 {
                     if (currentDepth < maxRecursionDepth)
                     {
@@ -100,15 +99,13 @@ private void GenerateFormatEntryDisplay(FormatEntry fe, int currentDepth)
                     continue;
                 }
 
-                FormatTextField ftf = obj as FormatTextField;
-                if (ftf != null)
+                if (obj is FormatTextField ftf)
                 {
                     this.AddToBuffer(ftf.text);
                     continue;
                 }
 
-                FormatPropertyField fpf = obj as FormatPropertyField;
-                if (fpf != null)
+                if (obj is FormatPropertyField fpf)
                 {
                     this.AddToBuffer(fpf.propertyValue);
                 }

diff --git a/src/System.Management.Automation/FormatAndOutput/common/DisplayDatabase/XmlLoaderBase.cs b/src/System.Management.Automation/FormatAndOutput/common/DisplayDatabase/XmlLoaderBase.cs
@@ -384,14 +384,10 @@ private bool MatchNodeNameHelper(XmlNode n, string s, bool allowAttributes)
                 match = true;
             }
 
-            if (match && !allowAttributes)
+            if (match && !allowAttributes && n is XmlElement e && e.Attributes.Count > 0)
             {
-                XmlElement e = n as XmlElement;
-                if (e != null && e.Attributes.Count > 0)
-                {
-                    // Error at XPath {0} in file {1}: The XML Element {2} does not allow attributes.
-                    ReportError(StringUtil.Format(FormatAndOutXmlLoadingStrings.AttributesNotAllowed, ComputeCurrentXPath(), FilePath, n.Name));
-                }
+                // Error at XPath {0} in file {1}: The XML Element {2} does not allow attributes.
+                ReportError(StringUtil.Format(FormatAndOutXmlLoadingStrings.AttributesNotAllowed, ComputeCurrentXPath(), FilePath, n.Name));
             }
 
             return match;

diff --git a/...ement.Automation/FormatAndOutput/common/DisplayDatabase/displayDescriptionData_Complex.cs b/...ement.Automation/FormatAndOutput/common/DisplayDatabase/displayDescriptionData_Complex.cs
@@ -179,14 +179,12 @@ internal static CustomItemBase Create(FormatToken token)
                 return new CustomItemNewline();
             }
 
-            var textToken = token as TextToken;
-            if (textToken != null)
+            if (token is TextToken textToken)
             {
                 return new CustomItemText { Text = textToken.text };
             }
 
-            var frameToken = token as FrameToken;
-            if (frameToken != null)
+            if (token is FrameToken frameToken)
             {
                 var frame = new CustomItemFrame
                 {
@@ -211,8 +209,7 @@ internal static CustomItemBase Create(FormatToken token)
                 return frame;
             }
 
-            var cpt = token as CompoundPropertyToken;
-            if (cpt != null)
+            if (token is CompoundPropertyToken cpt)
             {
                 var cie = new CustomItemExpression { EnumerateCollection = cpt.enumerateCollection };
 
@@ -234,11 +231,6 @@ internal static CustomItemBase Create(FormatToken token)
                 return cie;
             }
 
-            var fpt = token as FieldPropertyToken;
-            if (fpt != null)
-            {
-            }
-
             Diagnostics.Assert(false, "Unexpected formatting token kind");
 
             return null;

diff --git a/...nagement.Automation/FormatAndOutput/common/DisplayDatabase/displayDescriptionData_List.cs b/...nagement.Automation/FormatAndOutput/common/DisplayDatabase/displayDescriptionData_List.cs
@@ -318,8 +318,7 @@ internal ListControlEntryItem(ListControlItemDefinition definition)
                 Label = definition.label.text;
             }
 
-            FieldPropertyToken fpt = definition.formatTokenList[0] as FieldPropertyToken;
-            if (fpt != null)
+            if (definition.formatTokenList[0] is FieldPropertyToken fpt)
             {
                 if (fpt.fieldFormattingDirective.formatString != null)
                 {

diff --git a/...agement.Automation/FormatAndOutput/common/DisplayDatabase/displayDescriptionData_Table.cs b/...agement.Automation/FormatAndOutput/common/DisplayDatabase/displayDescriptionData_Table.cs
@@ -446,10 +446,9 @@ internal TableControlRow(TableRowDefinition rowdefinition) : this()
 
             foreach (TableRowItemDefinition itemdef in rowdefinition.rowItemDefinitionList)
             {
-                FieldPropertyToken fpt = itemdef.formatTokenList[0] as FieldPropertyToken;
                 TableControlColumn column;
 
-                if (fpt != null)
+                if (itemdef.formatTokenList[0] is FieldPropertyToken fpt)
                 {
                     column = new TableControlColumn(fpt.expression.expressionValue, itemdef.alignment,
                                     fpt.expression.isScriptBlock, fpt.fieldFormattingDirective.formatString);

diff --git a/...nagement.Automation/FormatAndOutput/common/DisplayDatabase/displayDescriptionData_Wide.cs b/...nagement.Automation/FormatAndOutput/common/DisplayDatabase/displayDescriptionData_Wide.cs
@@ -204,8 +204,7 @@ internal WideControlEntryItem()
 
         internal WideControlEntryItem(WideControlEntryDefinition definition) : this()
         {
-            FieldPropertyToken fpt = definition.formatTokenList[0] as FieldPropertyToken;
-            if (fpt != null)
+            if (definition.formatTokenList[0] is FieldPropertyToken fpt)
             {
                 DisplayEntry = new DisplayEntry(fpt.expression);
                 FormatString = fpt.fieldFormattingDirective.formatString;

diff --git a/src/System.Management.Automation/FormatAndOutput/common/DisplayDatabase/typeDataQuery.cs b/src/System.Management.Automation/FormatAndOutput/common/DisplayDatabase/typeDataQuery.cs
@@ -143,9 +143,8 @@ private int ComputeBestMatch(AppliesTo appliesTo, PSObject currentObject)
                 }
 
                 int currentMatch = BestMatchIndexUndefined;
-                TypeReference tr = r as TypeReference;
 
-                if (tr != null)
+                if (r is TypeReference tr)
                 {
                     // we have a type
                     currentMatch = MatchTypeIndex(tr.name, currentObject, ex);
@@ -486,9 +485,8 @@ private static void TraceHelper(ViewDefinition vd, bool isMatched)
                 foreach (TypeOrGroupReference togr in vd.appliesTo.referenceList)
                 {
                     StringBuilder sb = new StringBuilder();
-                    TypeReference tr = togr as TypeReference;
                     sb.Append(isMatched ? "MATCH FOUND" : "NOT MATCH");
-                    if (tr != null)
+                    if (togr is TypeReference tr)
                     {
                         sb.AppendFormat(
                             CultureInfo.InvariantCulture,
@@ -601,8 +599,7 @@ internal static AppliesTo GetAllApplicableTypes(TypeInfoDataBase db, AppliesTo a
             foreach (TypeOrGroupReference r in appliesTo.referenceList)
             {
                 // if it is a type reference, just add the type name
-                TypeReference tr = r as TypeReference;
-                if (tr != null)
+                if (r is TypeReference tr)
                 {
                     if (!allTypes.Contains(tr.name))
                         allTypes.Add(tr.name);

diff --git a/src/System.Management.Automation/FormatAndOutput/common/DisplayDatabase/typeDataXmlLoader.cs b/src/System.Management.Automation/FormatAndOutput/common/DisplayDatabase/typeDataXmlLoader.cs
@@ -1085,20 +1085,17 @@ private ComplexControlEntryDefinition LoadComplexControlEntryDefinitionFromObjec
 
         private FormatToken LoadFormatTokenFromObjectModel(CustomItemBase item, int viewIndex, string typeName)
         {
-            var newline = item as CustomItemNewline;
-            if (newline != null)
+            if (item is CustomItemNewline newline)
             {
                 return new NewLineToken { count = newline.Count };
             }
 
-            var text = item as CustomItemText;
-            if (text != null)
+            if (item is CustomItemText text)
             {
                 return new TextToken { text = text.Text };
             }
 
-            var expr = item as CustomItemExpression;
-            if (expr != null)
+            if (item is CustomItemExpression expr)
             {
                 var cpt = new CompoundPropertyToken { enumerateCollection = expr.EnumerateCollection };
 
@@ -1766,9 +1763,8 @@ private TextToken LoadTextToken(XmlNode n)
         private bool LoadStringResourceReference(XmlNode n, out StringResourceReference resource)
         {
             resource = null;
-            XmlElement e = n as XmlElement;
 
-            if (e == null)
+            if (n is not XmlElement e)
             {
                 // Error at XPath {0} in file {1}: Node should be an XmlElement.
                 this.ReportError(StringUtil.Format(FormatAndOutXmlLoadingStrings.NonXmlElementNode, ComputeCurrentXPath(), FilePath));

diff --git a/src/System.Management.Automation/FormatAndOutput/common/FormatMsgCtxManager.cs b/src/System.Management.Automation/FormatAndOutput/common/FormatMsgCtxManager.cs
@@ -68,8 +68,7 @@ internal OutputContext(OutputContext parentContextInStack)
         internal void Process(object o)
         {
             PacketInfoData formatData = o as PacketInfoData;
-            FormatEntryData fed = formatData as FormatEntryData;
-            if (fed != null)
+            if (formatData is FormatEntryData fed)
             {
                 OutputContext ctx = null;