Add support to experimental features

src/PowerShell.Core.Instrumentation/PowerShell.Core.Instrumentation.man

@@ -98,6 +98,29 @@
               value="0xD003"
               version="1"
               />
+          <!--ExperimentalFeature event-->
+          <event
+              channel="C_OPERATIONAL"
+              level="win:Error"
+              message="$(string.PS_PROVIDER.event.E_O_ExperimentalFeatureInvalidName.message)"
+              opcode="Constructor"
+              symbol="ExperimentalFeatureInvalidName"
+              task="ExperimentalFeature"
+              template="T_ExperimentalFeatureInvalidName"
+              value="0x3001"
+              version="1"
+              />
+          <event
+              channel="C_OPERATIONAL"
+              level="win:Error"
+              message="$(string.PS_PROVIDER.event.E_O_ExperimentalFeatureReadConfigError.message)"
+              opcode="Constructor"
+              symbol="ExperimentalFeatureReadConfigError"
+              task="ExperimentalFeature"
+              template="T_ExperimentalFeatureReadConfigError"
+              value="0x3002"
+              version="1"
+              />
           <!--M3P events-->
           <event
               channel="C_ANALYTIC"
@@ -2368,6 +2391,12 @@
               symbol="T_EXECUTEPIEPLINE"
               value="106"
               />
+          <task
+              message="$(string.PS_PROVIDER.task.T_ExperimentalFeature.message)"
+              name="ExperimentalFeature"
+              symbol="T_EXPERIMENTALFEATURE"
+              value="107"
+              />
           <task
               message="$(string.PS_PROVIDER.task.T_ScheduledJob.message)"
               name="ScheduledJob"
@@ -3927,6 +3956,30 @@
                 name="InnerException"
                 />
           </template>
+          <template tid="T_ExperimentalFeatureInvalidName">
+            <data
+                inType="win:UnicodeString"
+                name="Name"
+                />
+            <data
+                inType="win:UnicodeString"
+                name="Message"
+                />
+          </template>
+          <template tid="T_ExperimentalFeatureReadConfigError">
+            <data
+                inType="win:UnicodeString"
+                name="Name"
+                />
+            <data
+                inType="win:UnicodeString"
+                name="Message"
+                />
+            <data
+                inType="win:UnicodeString"
+                name="StackTrace"
+                />
+          </template>
           <template tid="T_TrackingGuid">
             <data
                 inType="win:GUID"
@@ -5428,6 +5481,18 @@
             id="PS_PROVIDER.task.T_ScheduledJob.message"
             value="PowerShell Scheduled Jobs"
             />
+        <string
+            id="PS_PROVIDER.event.E_O_ExperimentalFeatureInvalidName.message"
+            value="Experimental Feature Initialization: Ignore the experimental feature '%1' from the config file. %2"
+            />
+        <string
+            id="PS_PROVIDER.event.E_O_ExperimentalFeatureReadConfigError.message"
+            value="Experimental Feature Initialization: Failed to read the config file.%n Exception: %1 %n Message: %2 %n StackTrace: %3 %n"
+            />
+        <string
+            id="PS_PROVIDER.task.T_ExperimentalFeature.message"
+            value="PowerShell Experimental Features"
+            />
         <string
             id="PS_PROVIDER.task.T_NamedPipe.message"
             value="PowerShell Named Pipe IPC"

src/System.Management.Automation/CoreCLR/EventResource.cs

@@ -3,8 +3,8 @@
 
 #if UNIX
 /*
-    This code was generated by the tools\ResxGen\ResxGen.ps1 run against PowerShell-Core-Instrumentation.man.
-    To add or change logged events and the associated resources, edit PowerShell-Core-Instrumentation.man
+    This code was generated by the tools\ResxGen\ResxGen.ps1 run against PowerShell.Core.Instrumentation.man.
+    To add or change logged events and the associated resources, edit PowerShell.Core.Instrumentation.man
     then rerun ResxGen.ps1 to produce an updated CS and Resx file.
 */
 using System.Collections.Generic;
@@ -133,6 +133,12 @@ public static string GetMessage(int eventId, out int parameterCount)
                 case 12039:
                     parameterCount = 0;
                     return "PS_PROVIDEReventE_A_RUNSPACEPOOL_TRANSFER";
+                case 12289:
+                    parameterCount = 2;
+                    return "PS_PROVIDEReventE_O_ExperimentalFeatureInvalidName";
+                case 12290:
+                    parameterCount = 3;
+                    return "PS_PROVIDEReventE_O_ExperimentalFeatureReadConfigError";
                 case 24577:
                     parameterCount = 1;
                     return "PS_PROVIDEReventE_O_ISEExecuteScript";

src/System.Management.Automation/FormatAndOutput/DefaultFormatters/PowerShellCore_format_ps1xml.cs

@@ -230,6 +230,10 @@ internal static IEnumerable<ExtendedTypeDefinition> GetFormatData()
                 "System.Management.Automation.PSModuleInfo",
                 ViewsOf_System_Management_Automation_PSModuleInfo());
 
+            yield return new ExtendedTypeDefinition(
+                "System.Management.Automation.ExperimentalFeature",
+                ViewsOf_System_Management_Automation_ExperimentalFeature());
+
             var td46 = new ExtendedTypeDefinition(
                 "Microsoft.PowerShell.Commands.BasicHtmlWebResponseObject",
                 ViewsOf_Microsoft_PowerShell_Commands_BasicHtmlWebResponseObject());
@@ -1240,6 +1244,33 @@ private static IEnumerable<FormatViewDefinition> ViewsOf_System_Management_Autom
                 .EndList());
         }
 
+        private static IEnumerable<FormatViewDefinition> ViewsOf_System_Management_Automation_ExperimentalFeature()
+        {
+            yield return new FormatViewDefinition("ExperimentalFeature",
+                TableControl.Create()
+                    .AddHeader(Alignment.Left, width: 35)
+                    .AddHeader(Alignment.Right, width: 7)
+                    .AddHeader(Alignment.Left, width: 35)
+                    .AddHeader(Alignment.Left)
+                    .StartRowDefinition()
+                        .AddPropertyColumn("Name")
+                        .AddPropertyColumn("Enabled")
+                        .AddPropertyColumn("Source")
+                        .AddPropertyColumn("Description")
+                    .EndRowDefinition()
+                .EndTable());
+
+            yield return new FormatViewDefinition("ExperimentalFeature",
+                ListControl.Create()
+                    .StartEntry()
+                        .AddItemProperty("Name")
+                        .AddItemProperty("Enabled")
+                        .AddItemProperty("Source")
+                        .AddItemProperty("Description")
+                    .EndEntry()
+                .EndList());
+        }
+
         private static IEnumerable<FormatViewDefinition> ViewsOf_Microsoft_PowerShell_Commands_BasicHtmlWebResponseObject()
         {
             yield return new FormatViewDefinition("Microsoft.PowerShell.Commands.BasicHtmlWebResponseObject",

src/System.Management.Automation/engine/Attributes.cs

@@ -620,12 +620,55 @@ public ParameterAttribute()
         {
         }
 
+        /// <summary>
+        /// Initializes a new instance that is associated with an experimental feature.
+        /// </summary>
+        public ParameterAttribute(string experimentName, ExperimentAction experimentAction)
+        {
+            ExperimentalAttribute.ValidateArguments(experimentName, experimentAction);
+            ExperimentName = experimentName;
+            ExperimentAction = experimentAction;
+        }
+
         private string _parameterSetName = ParameterAttribute.AllParameterSets;
 
         private string _helpMessage;
         private string _helpMessageBaseName;
         private string _helpMessageResourceId;
 
+        #region Experimental Feature Related Properties
+
+        /// <summary>
+        /// Get name of the experimental feature this attribute is associated with.
+        /// </summary>
+        public string ExperimentName { get; }
+
+        /// <summary>
+        /// Get action for engine to take when the experimental feature is enabled.
+        /// </summary>
+        public ExperimentAction ExperimentAction { get; }
+
+        internal bool ToHide => EffectiveAction == ExperimentAction.Hide;
+        internal bool ToShow => EffectiveAction == ExperimentAction.Show;
+
+        /// <summary>
+        /// Get effective action to take at run time.
+        /// </summary>
+        private ExperimentAction EffectiveAction
+        {
+            get
+            {
+                if (_effectiveAction == ExperimentAction.None)
+                {
+                    _effectiveAction = ExperimentalFeature.GetActionToTake(ExperimentName, ExperimentAction);
+                }
+                return _effectiveAction;
+            }
+        }
+        private ExperimentAction _effectiveAction = default(ExperimentAction);
+
+        #endregion
+
         /// <summary>
         /// Gets and sets the parameter position. If not set, the parameter is named.
         /// </summary>

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs

@@ -1756,13 +1756,15 @@ private List<CompletionResult> GetResultForAttributeArgument(CompletionContext c
             {
                 PropertyInfo[] propertyInfos = attributeType.GetProperties(BindingFlags.Public | BindingFlags.Instance);
                 List<CompletionResult> result = new List<CompletionResult>();
-                foreach (PropertyInfo pro in propertyInfos)
+                foreach (PropertyInfo property in propertyInfos)
                 {
-                    //Ignore TypeId (all attributes inherit it)
-                    if (pro.Name != "TypeId" && (pro.Name.StartsWith(argName, StringComparison.OrdinalIgnoreCase)))
+                    // Ignore getter-only properties, including 'TypeId' (all attributes inherit it).
+                    if (!property.CanWrite) { continue; }
+
+                    if (property.Name.StartsWith(argName, StringComparison.OrdinalIgnoreCase))
                     {
-                        result.Add(new CompletionResult(pro.Name, pro.Name, CompletionResultType.Property,
-                            pro.PropertyType.ToString() + " " + pro.Name));
+                        result.Add(new CompletionResult(property.Name, property.Name, CompletionResultType.Property,
+                            property.PropertyType.ToString() + " " + property.Name));
                     }
                 }
                 return result;

src/System.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs

@@ -1698,12 +1698,10 @@ internal static string ConcatenateStringPathArguments(CommandElementAst stringAs
 
             foreach (ValidateArgumentsAttribute att in parameter.Parameter.ValidationAttributes)
             {
-                if (att is ValidateSetAttribute)
+                if (att is ValidateSetAttribute setAtt)
                 {
                     RemoveLastNullCompletionResult(result);
 
-                    var setAtt = (ValidateSetAttribute)att;
-
                     string wordToComplete = context.WordToComplete;
                     string quote = HandleDoubleAndSingleQuote(ref wordToComplete);
 
@@ -1712,6 +1710,8 @@ internal static string ConcatenateStringPathArguments(CommandElementAst stringAs
 
                     foreach (string value in setAtt.ValidValues)
                     {
+                        if (value == string.Empty) { continue; }
+
                         if (wordToComplete.Equals(value, StringComparison.OrdinalIgnoreCase))
                         {
                             string completionText = quote == string.Empty ? value : quote + value + quote;

src/System.Management.Automation/engine/CommandProcessor.cs

@@ -18,7 +18,7 @@ namespace System.Management.Automation
     /// </summary>
     internal class CommandProcessor : CommandProcessorBase
     {
-#region ctor
+        #region ctor
 
         static CommandProcessor()
         {
@@ -87,9 +87,10 @@ internal CommandProcessor(IScriptCommandInfo scriptCommandInfo, ExecutionContext
 
         // CommandProcessor
 
-#endregion ctor
+        #endregion ctor
+
+        #region internal members
 
-#region internal members
         /// <summary>
         /// Returns a CmdletParameterBinderController for the specified command
         /// </summary>
@@ -393,9 +394,9 @@ internal override void ProcessRecord()
             }
         }
 
-#endregion public_methods
+        #endregion public_methods
 
-#region helper_methods
+        #region helper_methods
 
         /// <summary>
         /// Tells whether it is the first call to Read
@@ -849,7 +850,7 @@ internal override bool IsHelpRequested(out string helpTarget, out HelpCategory h
             return base.IsHelpRequested(out helpTarget, out helpCategory);
         }
 
-#endregion helper_methods
+        #endregion helper_methods
     }
 }
 

src/System.Management.Automation/engine/CommandProcessorBase.cs

@@ -34,14 +34,31 @@ internal CommandProcessorBase()
         /// The metadata about the command to run.
         /// </param>
         ///
-        internal CommandProcessorBase(
-            CommandInfo commandInfo)
+        internal CommandProcessorBase(CommandInfo commandInfo)
         {
             if (commandInfo == null)
             {
                 throw PSTraceSource.NewArgumentNullException("commandInfo");
             }
 
+            if (commandInfo is IScriptCommandInfo scriptCommand)
+            {
+                ExperimentalAttribute expAttribute = scriptCommand.ScriptBlock.ExperimentalAttribute;
+                if (expAttribute != null && expAttribute.ToHide)
+                {
+                    string errorTemplate = expAttribute.ExperimentAction == ExperimentAction.Hide
+                        ? DiscoveryExceptions.ScriptDisabledWhenFeatureOn
+                        : DiscoveryExceptions.ScriptDisabledWhenFeatureOff;
+                    string errorMsg = StringUtil.Format(errorTemplate, expAttribute.ExperimentName);
+                    ErrorRecord errorRecord = new ErrorRecord(
+                        new InvalidOperationException(errorMsg),
+                        "ScriptCommandDisabled",
+                        ErrorCategory.InvalidOperation,
+                        commandInfo);
+                    throw new CmdletInvocationException(errorRecord);
+                }
+            }
+
             CommandInfo = commandInfo;
         }
 

src/System.Management.Automation/engine/CompiledCommandParameter.cs

@@ -64,6 +64,18 @@ internal CompiledCommandParameter(RuntimeDefinedParameter runtimeDefinedParamete
             // First, process attributes that aren't type conversions
             foreach (Attribute attribute in runtimeDefinedParameter.Attributes)
             {
+                if (processingDynamicParameters)
+                {
+                    // When processing dynamic parameters, the attribute list may contain experimental attributes
+                    // and disabled parameter attributes. We should ignore those attributes.
+                    // When processing non-dynamic parameters, the experimental attributes and disabled parameter
+                    // attributes have already been filtered out when constructing the RuntimeDefinedParameter.
+                    if (attribute is ExperimentalAttribute || attribute is ParameterAttribute param && param.ToHide)
+                    {
+                        continue;
+                    }
+                }
+
                 if (!(attribute is ArgumentTypeConverterAttribute))
                 {
                     ProcessAttribute(runtimeDefinedParameter.Name, attribute, ref validationAttributes, ref argTransformationAttributes, ref aliases);
@@ -78,7 +90,7 @@ internal CompiledCommandParameter(RuntimeDefinedParameter runtimeDefinedParamete
             }
 
             // Now process type converters
-            foreach (ArgumentTypeConverterAttribute attribute in runtimeDefinedParameter.Attributes.OfType<ArgumentTypeConverterAttribute>())
+            foreach (var attribute in runtimeDefinedParameter.Attributes.OfType<ArgumentTypeConverterAttribute>())
             {
                 ProcessAttribute(runtimeDefinedParameter.Name, attribute, ref validationAttributes, ref argTransformationAttributes, ref aliases);
             }
@@ -169,7 +181,15 @@ internal CompiledCommandParameter(MemberInfo member, bool processingDynamicParam
 
             foreach (Attribute attr in memberAttributes)
             {
-                ProcessAttribute(member.Name, attr, ref validationAttributes, ref argTransformationAttributes, ref aliases);
+                switch (attr)
+                {
+                    case ExperimentalAttribute _:
+                    case ParameterAttribute param when param.ToHide:
+                        break;
+                    default:
+                        ProcessAttribute(member.Name, attr, ref validationAttributes, ref argTransformationAttributes, ref aliases);
+                        break;
+                }
             }
 
             this.ValidationAttributes = validationAttributes == null
@@ -436,7 +456,6 @@ internal IEnumerable<ParameterSetSpecificMetadata> GetMatchingParameterSetData(u
             ref Collection<ArgumentTransformationAttribute> argTransformationAttributes,
             ref string[] aliases)
         {
-            // NTRAID#Windows Out Of Band Releases-926374-2005/12/22-JonN
             if (attribute == null)
                 return;