Use null propagation operator in Management and ConsoleHost (#17791)

src/Microsoft.PowerShell.Commands.Management/cimSupport/cmdletization/SessionBasedWrapper.cs

@@ -683,10 +683,7 @@ namespace Microsoft.PowerShell.Cmdletization
         public override void StopProcessing()
         {
             Job jobToStop = _parentJob;
-            if (jobToStop != null)
-            {
-                jobToStop.StopJob();
-            }
+            jobToStop?.StopJob();
 
             base.StopProcessing();
         }

src/Microsoft.PowerShell.Commands.Management/cimSupport/cmdletization/cim/cimChildJobBase.cs

@@ -315,10 +315,7 @@ namespace Microsoft.PowerShell.Cmdletization.Cim
                 this.ExceptionSafeWrapper(delegate
                 {
                     IObservable<T> observable = this.GetCimOperation();
-                    if (observable != null)
-                    {
-                        observable.Subscribe(this);
-                    }
+                    observable?.Subscribe(this);
                 });
             });
         }
@@ -522,10 +519,7 @@ namespace Microsoft.PowerShell.Cmdletization.Cim
             }
 
             CimCustomOptionsDictionary jobSpecificCustomOptions = this.GetJobSpecificCustomOptions();
-            if (jobSpecificCustomOptions != null)
-            {
-                jobSpecificCustomOptions.Apply(operationOptions, CimSensitiveValueConverter);
-            }
+            jobSpecificCustomOptions?.Apply(operationOptions, CimSensitiveValueConverter);
 
             return operationOptions;
         }

src/Microsoft.PowerShell.Commands.Management/commands/management/ContentCommandBase.cs

@@ -377,10 +377,7 @@ namespace Microsoft.PowerShell.Commands
             {
                 try
                 {
-                    if (holder.Writer != null)
-                    {
-                        holder.Writer.Close();
-                    }
+                    holder.Writer?.Close();
                 }
                 catch (Exception e) // Catch-all OK. 3rd party callout
                 {
@@ -414,10 +411,7 @@ namespace Microsoft.PowerShell.Commands
 
                 try
                 {
-                    if (holder.Reader != null)
-                    {
-                        holder.Reader.Close();
-                    }
+                    holder.Reader?.Close();
                 }
                 catch (Exception e) // Catch-all OK. 3rd party callout
                 {

src/Microsoft.PowerShell.Commands.Management/commands/management/Process.cs

@@ -938,10 +938,7 @@ namespace Microsoft.PowerShell.Commands
         {
             if (System.Threading.Interlocked.Decrement(ref _numberOfProcessesToWaitFor) == 0)
             {
-                if (_waitHandle != null)
-                {
-                    _waitHandle.Set();
-                }
+                _waitHandle?.Set();
             }
         }
 
@@ -1040,13 +1037,8 @@ namespace Microsoft.PowerShell.Commands
         /// <summary>
         /// StopProcessing.
         /// </summary>
-        protected override void StopProcessing()
-        {
-            if (_waitHandle != null)
-            {
-                _waitHandle.Set();
-            }
-        }
+        protected override void StopProcessing() => _waitHandle?.Set();
+
         #endregion Overrides
 
     }
@@ -2079,13 +2071,7 @@ namespace Microsoft.PowerShell.Commands
         /// <summary>
         /// Implements ^c, after creating a process.
         /// </summary>
-        protected override void StopProcessing()
-        {
-            if (_waithandle != null)
-            {
-                _waithandle.Set();
-            }
-        }
+        protected override void StopProcessing() => _waithandle?.Set();
 
         #endregion
 
@@ -2116,13 +2102,7 @@ namespace Microsoft.PowerShell.Commands
         /// <summary>
         /// When Process exits the wait handle is set.
         /// </summary>
-        private void myProcess_Exited(object sender, System.EventArgs e)
-        {
-            if (_waithandle != null)
-            {
-                _waithandle.Set();
-            }
-        }
+        private void myProcess_Exited(object sender, System.EventArgs e) => _waithandle?.Set();
 
         private string ResolveFilePath(string path)
         {
@@ -2221,15 +2201,8 @@ namespace Microsoft.PowerShell.Commands
         {
             Thread.Sleep(1000);
 
-            if (_outputWriter != null)
-            {
-                _outputWriter.Dispose();
-            }
-
-            if (_errorWriter != null)
-            {
-                _errorWriter.Dispose();
-            }
+            _outputWriter?.Dispose();
+            _errorWriter?.Dispose();
         }
 
         private void SetupInputOutputRedirection(Process p)

src/Microsoft.PowerShell.ConsoleHost/host/msh/ConsoleHost.cs

@@ -189,10 +189,7 @@ namespace Microsoft.PowerShell
                 if ((s_cpp.ServerMode && s_cpp.NamedPipeServerMode) || (s_cpp.ServerMode && s_cpp.SocketServerMode) || (s_cpp.NamedPipeServerMode && s_cpp.SocketServerMode))
                 {
                     s_tracer.TraceError("Conflicting server mode parameters, parameters must be used exclusively.");
-                    if (s_theConsoleHost != null)
-                    {
-                        s_theConsoleHost.ui.WriteErrorLine(ConsoleHostStrings.ConflictingServerModeParameters);
-                    }
+                    s_theConsoleHost?.ui.WriteErrorLine(ConsoleHostStrings.ConflictingServerModeParameters);
 
                     return ExitCodeBadCommandLineParameter;
                 }
@@ -501,10 +498,7 @@ namespace Microsoft.PowerShell
                     if (runspaceRef != null)
                     {
                         var runspace = runspaceRef.Runspace;
-                        if (runspace != null)
-                        {
-                            runspace.Close();
-                        }
+                        runspace?.Close();
                     }
                 }
             }
@@ -1266,15 +1260,8 @@ namespace Microsoft.PowerShell
                         StopTranscribing();
                     }
 
-                    if (_outputSerializer != null)
-                    {
-                        _outputSerializer.End();
-                    }
-
-                    if (_errorSerializer != null)
-                    {
-                        _errorSerializer.End();
-                    }
+                    _outputSerializer?.End();
+                    _errorSerializer?.End();
 
                     if (_runspaceRef != null)
                     {
@@ -2233,10 +2220,7 @@ namespace Microsoft.PowerShell
                     // For remote debugging block data coming from the main (not-nested)
                     // running command.
                     baseLoop = InputLoop.GetNonNestedLoop();
-                    if (baseLoop != null)
-                    {
-                        baseLoop.BlockCommandOutput();
-                    }
+                    baseLoop?.BlockCommandOutput();
                 }
 
                 //
@@ -2281,10 +2265,7 @@ namespace Microsoft.PowerShell
             finally
             {
                 _debuggerStopEventArgs = null;
-                if (baseLoop != null)
-                {
-                    baseLoop.ResumeCommandOutput();
-                }
+                baseLoop?.ResumeCommandOutput();
             }
         }
 
@@ -2670,10 +2651,7 @@ namespace Microsoft.PowerShell
                                 bht = _parent._breakHandlerThread;
                             }
 
-                            if (bht != null)
-                            {
-                                bht.Join();
-                            }
+                            bht?.Join();
 
                             // Once the pipeline has been executed, we toss any outstanding progress data and
                             // take down the display.

src/Microsoft.PowerShell.ConsoleHost/host/msh/ConsoleHostUserInterfaceProgress.cs

@@ -139,20 +139,14 @@ namespace Microsoft.PowerShell
         void
         PreWrite()
         {
-            if (_progPane != null)
-            {
-                _progPane.Hide();
-            }
+            _progPane?.Hide();
         }
 
         private
         void
         PostWrite()
         {
-            if (_progPane != null)
-            {
-                _progPane.Show();
-            }
+            _progPane?.Show();
         }
 
         private
@@ -178,20 +172,14 @@ namespace Microsoft.PowerShell
         void
         PreRead()
         {
-            if (_progPane != null)
-            {
-                _progPane.Hide();
-            }
+            _progPane?.Hide();
         }
 
         private
         void
         PostRead()
         {
-            if (_progPane != null)
-            {
-                _progPane.Show();
-            }
+            _progPane?.Show();
         }
 
         private

src/Microsoft.PowerShell.ConsoleHost/host/msh/Executor.cs

@@ -599,11 +599,9 @@ namespace Microsoft.PowerShell
         internal void ResumeCommandOutput()
         {
             RemotePipeline remotePipeline = _pipeline as RemotePipeline;
-            if (remotePipeline != null)
-            {
-                // Resumes data flow.
-                remotePipeline.ResumeIncomingData();
-            }
+
+            // Resumes data flow.
+            remotePipeline?.ResumeIncomingData();
         }
 
         /// <summary>
@@ -697,10 +695,7 @@ namespace Microsoft.PowerShell
                 temp = s_currentExecutor;
             }
 
-            if (temp != null)
-            {
-                temp.Cancel();
-            }
+            temp?.Cancel();
         }
 
         // These statics are threadsafe, as there can be only one instance of ConsoleHost in a process at a time, and access