From 3d2cbcef6982af82f57aaa9e359edead2419a0d8 Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Mon, 11 Jan 2021 21:24:12 -0800
Subject: [PATCH 1/9] Update the ICommandPredictor interface with API changes

---
 .../CommandPrediction/CommandPrediction.cs    | 72 +++++++++++++++----
 .../CommandPrediction/ICommandPredictor.cs    | 31 +++++---
 2 files changed, 80 insertions(+), 23 deletions(-)

diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
index 30deb1b3093..2c2e83c6efb 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
@@ -27,15 +27,21 @@ public sealed class PredictionResult
         /// </summary>
         public string Name { get; }
 
+        /// <summary>
+        /// Gets the name of the predictor.
+        /// </summary>
+        public string Session { get; }
+
         /// <summary>
         /// Gets the suggestions.
         /// </summary>
         public IReadOnlyList<PredictiveSuggestion> Suggestions { get; }
 
-        internal PredictionResult(Guid id, string name, List<PredictiveSuggestion> suggestions)
+        internal PredictionResult(Guid id, string name, string session, List<PredictiveSuggestion> suggestions)
         {
             Id = id;
             Name = name;
+            Session = session;
             Suggestions = suggestions;
         }
     }
@@ -48,22 +54,24 @@ public static class CommandPrediction
         /// <summary>
         /// Collect the predictive suggestions from registered predictors using the default timeout.
         /// </summary>
+        /// <param name="client">Represents the client that initiates the call.</param>
         /// <param name="ast">The <see cref="Ast"/> object from parsing the current command line input.</param>
         /// <param name="astTokens">The <see cref="Token"/> objects from parsing the current command line input.</param>
         /// <returns>A list of <see cref="PredictionResult"/> objects.</returns>
-        public static Task<List<PredictionResult>?> PredictInput(Ast ast, Token[] astTokens)
+        public static Task<List<PredictionResult>?> PredictInput(string client, Ast ast, Token[] astTokens)
         {
-            return PredictInput(ast, astTokens, millisecondsTimeout: 20);
+            return PredictInput(client, ast, astTokens, millisecondsTimeout: 20);
         }
 
         /// <summary>
         /// Collect the predictive suggestions from registered predictors using the specified timeout.
         /// </summary>
+        /// <param name="client">Represents the client that initiates the call.</param>
         /// <param name="ast">The <see cref="Ast"/> object from parsing the current command line input.</param>
         /// <param name="astTokens">The <see cref="Token"/> objects from parsing the current command line input.</param>
         /// <param name="millisecondsTimeout">The milliseconds to timeout.</param>
         /// <returns>A list of <see cref="PredictionResult"/> objects.</returns>
-        public static async Task<List<PredictionResult>?> PredictInput(Ast ast, Token[] astTokens, int millisecondsTimeout)
+        public static async Task<List<PredictionResult>?> PredictInput(string client, Ast ast, Token[] astTokens, int millisecondsTimeout)
         {
             Requires.Condition(millisecondsTimeout > 0, nameof(millisecondsTimeout));
 
@@ -85,8 +93,10 @@ public static class CommandPrediction
                     state =>
                     {
                         var predictor = (ICommandPredictor)state!;
-                        List<PredictiveSuggestion>? texts = predictor.GetSuggestion(context, cancellationSource.Token);
-                        return texts?.Count > 0 ? new PredictionResult(predictor.Id, predictor.Name, texts) : null;
+                        var (session, list) = predictor.GetSuggestion(client, context, cancellationSource.Token);
+                        return session != null && list?.Count > 0
+                            ? new PredictionResult(predictor.Id, predictor.Name, session, list)
+                            : null;
                     },
                     predictor,
                     cancellationSource.Token,
@@ -99,7 +109,7 @@ await Task.WhenAny(
                 Task.Delay(millisecondsTimeout, cancellationSource.Token)).ConfigureAwait(false);
             cancellationSource.Cancel();
 
-            var results = new List<PredictionResult>(predictors.Count);
+            var resultList = new List<PredictionResult>(predictors.Count);
             foreach (Task<PredictionResult?> task in tasks)
             {
                 if (task.IsCompletedSuccessfully)
@@ -107,19 +117,20 @@ await Task.WhenAny(
                     PredictionResult? result = task.Result;
                     if (result != null)
                     {
-                        results.Add(result);
+                        resultList.Add(result);
                     }
                 }
             }
 
-            return results;
+            return resultList;
         }
 
         /// <summary>
         /// Allow registered predictors to do early processing when a command line is accepted.
         /// </summary>
+        /// <param name="client">Represents the client that initiates the call.</param>
         /// <param name="history">History command lines provided as references for prediction.</param>
-        public static void OnCommandLineAccepted(IReadOnlyList<string> history)
+        public static void OnCommandLineAccepted(string client, IReadOnlyList<string> history)
         {
             Requires.NotNull(history, nameof(history));
 
@@ -134,7 +145,38 @@ public static void OnCommandLineAccepted(IReadOnlyList<string> history)
                 if (predictor.SupportEarlyProcessing)
                 {
                     ThreadPool.QueueUserWorkItem<ICommandPredictor>(
-                        state => state.StartEarlyProcessing(history),
+                        state => state.StartEarlyProcessing(client, history),
+                        predictor,
+                        preferLocal: false);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Send feedback to a predictor when one or more suggestions from it were displayed to the user.
+        /// </summary>
+        /// <param name="predictorId">The identifier of the predictor whose prediction result was accepted.</param>
+        /// <param name="session">The mini-session where the displayed suggestions came from.</param>
+        /// <param name="countOrIndex">
+        /// When the value is <code>> 0</code>, it's the number of displayed suggestions from the list returned in <see cref="session"/>, starting from the index 0.
+        /// When the value is <code><= 0</code>, it means a single suggestion from the list got displayed, and the index is the absolute value.
+        /// </param>
+        public static void OnSuggestionDisplayed(Guid predictorId, string session, int countOrIndex)
+        {
+            Requires.NotNullOrEmpty(session, nameof(session));
+
+            var predictors = SubsystemManager.GetSubsystems<ICommandPredictor>();
+            if (predictors.Count == 0)
+            {
+                return;
+            }
+
+            foreach (ICommandPredictor predictor in predictors)
+            {
+                if (predictor.AcceptFeedback && predictor.Id == predictorId)
+                {
+                    ThreadPool.QueueUserWorkItem<ICommandPredictor>(
+                        state => state.OnSuggestionDisplayed(session, countOrIndex),
                         predictor,
                         preferLocal: false);
                 }
@@ -142,12 +184,14 @@ public static void OnCommandLineAccepted(IReadOnlyList<string> history)
         }
 
         /// <summary>
-        /// Send feedback to predictors about their last suggestions.
+        /// Send feedback to a predictor when a suggestion from it was accepted.
         /// </summary>
         /// <param name="predictorId">The identifier of the predictor whose prediction result was accepted.</param>
+        /// <param name="session">The mini-session where the accepted suggestion came from.</param>
         /// <param name="suggestionText">The accepted suggestion text.</param>
-        public static void OnSuggestionAccepted(Guid predictorId, string suggestionText)
+        public static void OnSuggestionAccepted(Guid predictorId, string session, string suggestionText)
         {
+            Requires.NotNullOrEmpty(session, nameof(session));
             Requires.NotNullOrEmpty(suggestionText, nameof(suggestionText));
 
             var predictors = SubsystemManager.GetSubsystems<ICommandPredictor>();
@@ -161,7 +205,7 @@ public static void OnSuggestionAccepted(Guid predictorId, string suggestionText)
                 if (predictor.AcceptFeedback && predictor.Id == predictorId)
                 {
                     ThreadPool.QueueUserWorkItem<ICommandPredictor>(
-                        state => state.OnSuggestionAccepted(suggestionText),
+                        state => state.OnSuggestionAccepted(session, suggestionText),
                         predictor,
                         preferLocal: false);
                 }
diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
index 0edd768cf89..48e864cc305 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
@@ -40,22 +40,35 @@ public interface ICommandPredictor : ISubsystem
         /// A command line was accepted to execute.
         /// The predictor can start processing early as needed with the latest history.
         /// </summary>
+        /// <param name="clientId">Represents the client that initiates the call.</param>
         /// <param name="history">History command lines provided as references for prediction.</param>
-        void StartEarlyProcessing(IReadOnlyList<string> history);
+        void StartEarlyProcessing(string clientId, IReadOnlyList<string> history);
 
         /// <summary>
-        /// The suggestion given by the predictor was accepted.
+        /// Get the predictive suggestions. It indicates the start of a suggestion rendering session.
         /// </summary>
-        /// <param name="acceptedSuggestion">The accepted suggestion text.</param>
-        void OnSuggestionAccepted(string acceptedSuggestion);
+        /// <param name="clientId">Represents the client that initiates the call.</param>
+        /// <param name="context">The <see cref="PredictionContext"/> object to be used for prediction.</param>
+        /// <param name="cancellationToken">The cancellation token to cancel the prediction.</param>
+        /// <returns>A value tuple consist of a session id, and a list of predictive suggestions.</returns>
+        (string? Session, List<PredictiveSuggestion>? List) GetSuggestion(string clientId, PredictionContext context, CancellationToken cancellationToken);
 
         /// <summary>
-        /// Get the predictive suggestions.
+        /// One or more suggestions provided by the predictor were displayed to the user.
         /// </summary>
-        /// <param name="context">The <see cref="PredictionContext"/> object to be used for prediction.</param>
-        /// <param name="cancellationToken">The cancellation token to cancel the prediction.</param>
-        /// <returns>A list of predictive suggestions.</returns>
-        List<PredictiveSuggestion>? GetSuggestion(PredictionContext context, CancellationToken cancellationToken);
+        /// <param name="session">The mini-session where the displayed suggestions came from.</param>
+        /// <param name="countOrIndex">
+        /// When the value is <code>> 0</code>, it's the number of displayed suggestions from the list returned in <see cref="session"/>, starting from the index 0.
+        /// When the value is <code><= 0</code>, it means a single suggestion from the list got displayed, and the index is the absolute value.
+        /// </param>
+        void OnSuggestionDisplayed(string session, int countOrIndex);
+
+        /// <summary>
+        /// The suggestion provided by the predictor was accepted.
+        /// </summary>
+        /// <param name="session">Represents the mini-session where the accepted suggestion came from.</param>
+        /// <param name="acceptedSuggestion">The accepted suggestion text.</param>
+        void OnSuggestionAccepted(string session, string acceptedSuggestion);
     }
 
     /// <summary>

From 589666e77110d7d578b2bfa63e9d613004208aa6 Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Tue, 12 Jan 2021 13:17:17 -0800
Subject: [PATCH 2/9] Use 'uint' type for the mini-session id

---
 .../CommandPrediction/CommandPrediction.cs    | 19 +++++------
 .../CommandPrediction/ICommandPredictor.cs    | 33 ++++++++++++++++---
 2 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
index 2c2e83c6efb..bbc0690073a 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
@@ -28,16 +28,16 @@ public sealed class PredictionResult
         public string Name { get; }
 
         /// <summary>
-        /// Gets the name of the predictor.
+        /// Gets the mini-session id that represents a specific invocation to the <see cref="ICommandPredictor.GetSuggestion"/> API of the predictor.
         /// </summary>
-        public string Session { get; }
+        public uint Session { get; }
 
         /// <summary>
         /// Gets the suggestions.
         /// </summary>
         public IReadOnlyList<PredictiveSuggestion> Suggestions { get; }
 
-        internal PredictionResult(Guid id, string name, string session, List<PredictiveSuggestion> suggestions)
+        internal PredictionResult(Guid id, string name, uint session, List<PredictiveSuggestion> suggestions)
         {
             Id = id;
             Name = name;
@@ -93,9 +93,9 @@ public static class CommandPrediction
                     state =>
                     {
                         var predictor = (ICommandPredictor)state!;
-                        var (session, list) = predictor.GetSuggestion(client, context, cancellationSource.Token);
-                        return session != null && list?.Count > 0
-                            ? new PredictionResult(predictor.Id, predictor.Name, session, list)
+                        SuggestionPackage pkg = predictor.GetSuggestion(client, context, cancellationSource.Token);
+                        return pkg.Session.HasValue && pkg.SuggestionEntries?.Count > 0
+                            ? new PredictionResult(predictor.Id, predictor.Name, pkg.Session.Value, pkg.SuggestionEntries)
                             : null;
                     },
                     predictor,
@@ -161,10 +161,8 @@ public static void OnCommandLineAccepted(string client, IReadOnlyList<string> hi
         /// When the value is <code>> 0</code>, it's the number of displayed suggestions from the list returned in <see cref="session"/>, starting from the index 0.
         /// When the value is <code><= 0</code>, it means a single suggestion from the list got displayed, and the index is the absolute value.
         /// </param>
-        public static void OnSuggestionDisplayed(Guid predictorId, string session, int countOrIndex)
+        public static void OnSuggestionDisplayed(Guid predictorId, uint session, int countOrIndex)
         {
-            Requires.NotNullOrEmpty(session, nameof(session));
-
             var predictors = SubsystemManager.GetSubsystems<ICommandPredictor>();
             if (predictors.Count == 0)
             {
@@ -189,9 +187,8 @@ public static void OnSuggestionDisplayed(Guid predictorId, string session, int c
         /// <param name="predictorId">The identifier of the predictor whose prediction result was accepted.</param>
         /// <param name="session">The mini-session where the accepted suggestion came from.</param>
         /// <param name="suggestionText">The accepted suggestion text.</param>
-        public static void OnSuggestionAccepted(Guid predictorId, string session, string suggestionText)
+        public static void OnSuggestionAccepted(Guid predictorId, uint session, string suggestionText)
         {
-            Requires.NotNullOrEmpty(session, nameof(session));
             Requires.NotNullOrEmpty(suggestionText, nameof(suggestionText));
 
             var predictors = SubsystemManager.GetSubsystems<ICommandPredictor>();
diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
index 48e864cc305..0cf72fd4ebc 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
@@ -50,8 +50,8 @@ public interface ICommandPredictor : ISubsystem
         /// <param name="clientId">Represents the client that initiates the call.</param>
         /// <param name="context">The <see cref="PredictionContext"/> object to be used for prediction.</param>
         /// <param name="cancellationToken">The cancellation token to cancel the prediction.</param>
-        /// <returns>A value tuple consist of a session id, and a list of predictive suggestions.</returns>
-        (string? Session, List<PredictiveSuggestion>? List) GetSuggestion(string clientId, PredictionContext context, CancellationToken cancellationToken);
+        /// <returns>An instance of <see cref="SuggestionPackage"/>.</returns>
+        SuggestionPackage GetSuggestion(string clientId, PredictionContext context, CancellationToken cancellationToken);
 
         /// <summary>
         /// One or more suggestions provided by the predictor were displayed to the user.
@@ -61,14 +61,14 @@ public interface ICommandPredictor : ISubsystem
         /// When the value is <code>> 0</code>, it's the number of displayed suggestions from the list returned in <see cref="session"/>, starting from the index 0.
         /// When the value is <code><= 0</code>, it means a single suggestion from the list got displayed, and the index is the absolute value.
         /// </param>
-        void OnSuggestionDisplayed(string session, int countOrIndex);
+        void OnSuggestionDisplayed(uint session, int countOrIndex);
 
         /// <summary>
         /// The suggestion provided by the predictor was accepted.
         /// </summary>
         /// <param name="session">Represents the mini-session where the accepted suggestion came from.</param>
         /// <param name="acceptedSuggestion">The accepted suggestion text.</param>
-        void OnSuggestionAccepted(string session, string acceptedSuggestion);
+        void OnSuggestionAccepted(uint session, string acceptedSuggestion);
     }
 
     /// <summary>
@@ -173,4 +173,29 @@ public PredictiveSuggestion(string suggestion, string? toolTip)
             ToolTip = toolTip;
         }
     }
+
+    /// <summary>
+    /// A package returned from <see cref="ICommandPredictor.GetSuggestion"/>.
+    /// </summary>
+    public struct SuggestionPackage
+    {
+        /// <summary>
+        /// The mini-session that represents a specific invocation to <see cref="ICommandPredictor.GetSuggestion"/>.
+        /// </summary>
+        public uint? Session { get; }
+
+        /// <summary>
+        /// Suggestion entries returned from that mini-session.
+        /// </summary>
+        public List<PredictiveSuggestion>? SuggestionEntries { get; }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SuggestionPackage"/> struct.
+        /// </summary>
+        public SuggestionPackage(uint session, List<PredictiveSuggestion> suggestionEntries)
+        {
+            Session = session;
+            SuggestionEntries = suggestionEntries;
+        }
+    }
 }

From 203683e96bcae0685e298cf873760e51e595aabd Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Tue, 12 Jan 2021 21:26:08 -0800
Subject: [PATCH 3/9] Minor update

---
 .../engine/Subsystem/CommandPrediction/CommandPrediction.cs   | 4 +---
 .../engine/Subsystem/CommandPrediction/ICommandPredictor.cs   | 2 +-
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
index bbc0690073a..385839df847 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
@@ -94,9 +94,7 @@ public static class CommandPrediction
                     {
                         var predictor = (ICommandPredictor)state!;
                         SuggestionPackage pkg = predictor.GetSuggestion(client, context, cancellationSource.Token);
-                        return pkg.Session.HasValue && pkg.SuggestionEntries?.Count > 0
-                            ? new PredictionResult(predictor.Id, predictor.Name, pkg.Session.Value, pkg.SuggestionEntries)
-                            : null;
+                        return pkg.SuggestionEntries?.Count > 0 ? new PredictionResult(predictor.Id, predictor.Name, pkg.Session, pkg.SuggestionEntries) : null;
                     },
                     predictor,
                     cancellationSource.Token,
diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
index 0cf72fd4ebc..ee88dd5c507 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
@@ -182,7 +182,7 @@ public struct SuggestionPackage
         /// <summary>
         /// The mini-session that represents a specific invocation to <see cref="ICommandPredictor.GetSuggestion"/>.
         /// </summary>
-        public uint? Session { get; }
+        public uint Session { get; }
 
         /// <summary>
         /// Suggestion entries returned from that mini-session.

From 4eb7aac1cce4589a503aa9c6f84f666be75e5008 Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Wed, 13 Jan 2021 09:07:41 -0800
Subject: [PATCH 4/9] Fix script that create new NuGet package

---
 tools/packaging/packaging.psm1 | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/packaging/packaging.psm1 b/tools/packaging/packaging.psm1
index aaaee8688d0..3d996f338aa 100644
--- a/tools/packaging/packaging.psm1
+++ b/tools/packaging/packaging.psm1
@@ -2367,6 +2367,11 @@ function CleanupGeneratedSourceCode
             Pattern = "[System.Runtime.CompilerServices.CompilerGeneratedAttribute, System.Runtime.CompilerServices.NullableContextAttribute((byte)2)]"
             Replacement = "/* [System.Runtime.CompilerServices.CompilerGeneratedAttribute, System.Runtime.CompilerServices.NullableContextAttribute((byte)2)] */ "
         },
+        @{
+            ApplyTo = @("System.Management.Automation")
+            Pattern = "[System.Runtime.CompilerServices.CompilerGeneratedAttribute, System.Runtime.CompilerServices.IsReadOnlyAttribute]"
+            Replacement = "/* [System.Runtime.CompilerServices.CompilerGeneratedAttribute, System.Runtime.CompilerServices.IsReadOnlyAttribute] */ "
+        },
         @{
             ApplyTo = @("System.Management.Automation", "Microsoft.PowerShell.ConsoleHost")
             Pattern = "[System.Runtime.CompilerServices.NullableAttribute((byte)2)]"

From 4500afb681e2cefa70c7815a2bf716bef530a90a Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Thu, 21 Jan 2021 17:35:42 -0800
Subject: [PATCH 5/9] Address CodeFactor issues

---
 .../Subsystem/CommandPrediction/CommandPrediction.cs   |  4 ++--
 .../Subsystem/CommandPrediction/ICommandPredictor.cs   | 10 ++++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
index 385839df847..b0c15cb123d 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
@@ -156,8 +156,8 @@ public static void OnCommandLineAccepted(string client, IReadOnlyList<string> hi
         /// <param name="predictorId">The identifier of the predictor whose prediction result was accepted.</param>
         /// <param name="session">The mini-session where the displayed suggestions came from.</param>
         /// <param name="countOrIndex">
-        /// When the value is <code>> 0</code>, it's the number of displayed suggestions from the list returned in <see cref="session"/>, starting from the index 0.
-        /// When the value is <code><= 0</code>, it means a single suggestion from the list got displayed, and the index is the absolute value.
+        /// When the value is greater than 0, it's the number of displayed suggestions from the list returned in <paramref name="session"/>, starting from the index 0.
+        /// When the value is less than or equal to 0, it means a single suggestion from the list got displayed, and the index is the absolute value.
         /// </param>
         public static void OnSuggestionDisplayed(Guid predictorId, uint session, int countOrIndex)
         {
diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
index ee88dd5c507..37c98c7fb48 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
@@ -58,8 +58,8 @@ public interface ICommandPredictor : ISubsystem
         /// </summary>
         /// <param name="session">The mini-session where the displayed suggestions came from.</param>
         /// <param name="countOrIndex">
-        /// When the value is <code>> 0</code>, it's the number of displayed suggestions from the list returned in <see cref="session"/>, starting from the index 0.
-        /// When the value is <code><= 0</code>, it means a single suggestion from the list got displayed, and the index is the absolute value.
+        /// When the value is greater than 0, it's the number of displayed suggestions from the list returned in <paramref name="session"/>, starting from the index 0.
+        /// When the value is less than or equal to 0, it means a single suggestion from the list got displayed, and the index is the absolute value.
         /// </param>
         void OnSuggestionDisplayed(uint session, int countOrIndex);
 
@@ -180,18 +180,20 @@ public PredictiveSuggestion(string suggestion, string? toolTip)
     public struct SuggestionPackage
     {
         /// <summary>
-        /// The mini-session that represents a specific invocation to <see cref="ICommandPredictor.GetSuggestion"/>.
+        /// Gets the mini-session that represents a specific invocation to <see cref="ICommandPredictor.GetSuggestion"/>.
         /// </summary>
         public uint Session { get; }
 
         /// <summary>
-        /// Suggestion entries returned from that mini-session.
+        /// Gets the suggestion entries returned from that mini-session.
         /// </summary>
         public List<PredictiveSuggestion>? SuggestionEntries { get; }
 
         /// <summary>
         /// Initializes a new instance of the <see cref="SuggestionPackage"/> struct.
         /// </summary>
+        /// <param name="session">The mini-session where suggestions came from.</param>
+        /// <param name="suggestionEntries">The suggestions to return.</param>
         public SuggestionPackage(uint session, List<PredictiveSuggestion> suggestionEntries)
         {
             Session = session;

From e3eb21dbddc8e1e9c46846372e7d768357401ae4 Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Fri, 22 Jan 2021 10:44:12 -0800
Subject: [PATCH 6/9] Update tests and also add more tests

---
 test/xUnit/csharp/test_Prediction.cs | 80 ++++++++++++++++++----------
 test/xUnit/csharp/test_Subsystem.cs  | 10 ++--
 2 files changed, 59 insertions(+), 31 deletions(-)

diff --git a/test/xUnit/csharp/test_Prediction.cs b/test/xUnit/csharp/test_Prediction.cs
index 4d67c850f6d..a034a6b77f1 100644
--- a/test/xUnit/csharp/test_Prediction.cs
+++ b/test/xUnit/csharp/test_Prediction.cs
@@ -20,9 +20,9 @@ public class MyPredictor : ICommandPredictor
 
         public List<string> AcceptedSuggestions { get; }
 
-        public static readonly MyPredictor SlowPredictor;
+        public List<string> DisplayedSuggestions { get; }
 
-        public static readonly MyPredictor FastPredictor;
+        public static readonly MyPredictor SlowPredictor, FastPredictor;
 
         static MyPredictor()
         {
@@ -48,6 +48,7 @@ private MyPredictor(Guid id, string name, string description, bool delay)
 
             History = new List<string>();
             AcceptedSuggestions = new List<string>();
+            DisplayedSuggestions = new List<string>();
         }
 
         public Guid Id => _id;
@@ -60,17 +61,25 @@ private MyPredictor(Guid id, string name, string description, bool delay)
 
         bool ICommandPredictor.AcceptFeedback => true;
 
-        public void StartEarlyProcessing(IReadOnlyList<string> history)
+        public void StartEarlyProcessing(string clientId, IReadOnlyList<string> history)
         {
-            History.AddRange(history);
+            foreach (string item in history)
+            {
+                History.Add($"{clientId}-{item}");
+            }
+        }
+
+        public void OnSuggestionDisplayed(uint session, int countOrIndex)
+        {
+            DisplayedSuggestions.Add($"{session}-{countOrIndex}");
         }
 
-        public void OnSuggestionAccepted(string acceptedSuggestion)
+        public void OnSuggestionAccepted(uint session, string acceptedSuggestion)
         {
-            AcceptedSuggestions.Add(acceptedSuggestion);
+            AcceptedSuggestions.Add($"{session}-{acceptedSuggestion}");
         }
 
-        public List<PredictiveSuggestion> GetSuggestion(PredictionContext context, CancellationToken cancellationToken)
+        public SuggestionPackage GetSuggestion(string clientId, PredictionContext context, CancellationToken cancellationToken)
         {
             if (_delay)
             {
@@ -81,24 +90,30 @@ public List<PredictiveSuggestion> GetSuggestion(PredictionContext context, Cance
 
             // You can get the user input from the AST.
             var userInput = context.InputAst.Extent.Text;
-            return new List<PredictiveSuggestion> {
-                new PredictiveSuggestion($"{userInput} TEST-1 from {Name}"),
-                new PredictiveSuggestion($"{userInput} TeSt-2 from {Name}"),
+            var entries = new List<PredictiveSuggestion> {
+                new PredictiveSuggestion($"'{userInput}' from '{clientId}' - TEST-1 from {Name}"),
+                new PredictiveSuggestion($"'{userInput}' from '{clientId}' - TeSt-2 from {Name}"),
             };
+
+            return new SuggestionPackage(56, entries);
         }
     }
 
     public static class CommandPredictionTests
     {
+        private const string client = "PredictionTest";
+        private const uint session = 56;
+
         [Fact]
         public static void PredictInput()
         {
+            const string input = "Hello world";
             MyPredictor slow = MyPredictor.SlowPredictor;
             MyPredictor fast = MyPredictor.FastPredictor;
-            Ast ast = Parser.ParseInput("Hello world", out Token[] tokens, out _);
+            Ast ast = Parser.ParseInput(input, out Token[] tokens, out _);
 
             // Returns null when no predictor implementation registered
-            List<PredictionResult> results = CommandPrediction.PredictInput(ast, tokens).Result;
+            List<PredictionResult> results = CommandPrediction.PredictInput(client, ast, tokens).Result;
             Assert.Null(results);
 
             try
@@ -111,32 +126,35 @@ public static void PredictInput()
                 // cannot finish before the specified timeout.
                 // The specified timeout is exaggerated to make the test reliable.
                 // xUnit must spin up a lot tasks, which makes the test unreliable when the time difference between 'delay' and 'timeout' is small.
-                results = CommandPrediction.PredictInput(ast, tokens, millisecondsTimeout: 1000).Result;
+                results = CommandPrediction.PredictInput(client, ast, tokens, millisecondsTimeout: 1000).Result;
                 Assert.Single(results);
 
                 PredictionResult res = results[0];
                 Assert.Equal(fast.Id, res.Id);
+                Assert.Equal(session, res.Session);
                 Assert.Equal(2, res.Suggestions.Count);
-                Assert.Equal($"Hello world TEST-1 from {fast.Name}", res.Suggestions[0].SuggestionText);
-                Assert.Equal($"Hello world TeSt-2 from {fast.Name}", res.Suggestions[1].SuggestionText);
+                Assert.Equal($"'{input}' from '{client}' - TEST-1 from {fast.Name}", res.Suggestions[0].SuggestionText);
+                Assert.Equal($"'{input}' from '{client}' - TeSt-2 from {fast.Name}", res.Suggestions[1].SuggestionText);
 
                 // Expect the results from both 'slow' and 'fast' predictors
                 // Same here -- the specified timeout is exaggerated to make the test reliable.
                 // xUnit must spin up a lot tasks, which makes the test unreliable when the time difference between 'delay' and 'timeout' is small.
-                results = CommandPrediction.PredictInput(ast, tokens, millisecondsTimeout: 4000).Result;
+                results = CommandPrediction.PredictInput(client, ast, tokens, millisecondsTimeout: 4000).Result;
                 Assert.Equal(2, results.Count);
 
                 PredictionResult res1 = results[0];
                 Assert.Equal(slow.Id, res1.Id);
+                Assert.Equal(session, res1.Session);
                 Assert.Equal(2, res1.Suggestions.Count);
-                Assert.Equal($"Hello world TEST-1 from {slow.Name}", res1.Suggestions[0].SuggestionText);
-                Assert.Equal($"Hello world TeSt-2 from {slow.Name}", res1.Suggestions[1].SuggestionText);
+                Assert.Equal($"'{input}' from '{client}' - TEST-1 from {slow.Name}", res1.Suggestions[0].SuggestionText);
+                Assert.Equal($"'{input}' from '{client}' - TeSt-2 from {slow.Name}", res1.Suggestions[1].SuggestionText);
 
                 PredictionResult res2 = results[1];
                 Assert.Equal(fast.Id, res2.Id);
+                Assert.Equal(session, res2.Session);
                 Assert.Equal(2, res2.Suggestions.Count);
-                Assert.Equal($"Hello world TEST-1 from {fast.Name}", res2.Suggestions[0].SuggestionText);
-                Assert.Equal($"Hello world TeSt-2 from {fast.Name}", res2.Suggestions[1].SuggestionText);
+                Assert.Equal($"'{input}' from '{client}' - TEST-1 from {fast.Name}", res2.Suggestions[0].SuggestionText);
+                Assert.Equal($"'{input}' from '{client}' - TeSt-2 from {fast.Name}", res2.Suggestions[1].SuggestionText);
             }
             finally
             {
@@ -160,8 +178,10 @@ public static void Feedback()
                 var history = new[] { "hello", "world" };
                 var ids = new HashSet<Guid> { slow.Id, fast.Id };
 
-                CommandPrediction.OnCommandLineAccepted(history);
-                CommandPrediction.OnSuggestionAccepted(slow.Id, "Yeah");
+                CommandPrediction.OnCommandLineAccepted(client, history);
+                CommandPrediction.OnSuggestionDisplayed(slow.Id, session, 2);
+                CommandPrediction.OnSuggestionDisplayed(fast.Id, session, -1);
+                CommandPrediction.OnSuggestionAccepted(slow.Id, session, "Yeah");
 
                 // The calls to 'StartEarlyProcessing' and 'OnSuggestionAccepted' are queued in thread pool,
                 // so we wait a bit to make sure the calls are done.
@@ -171,15 +191,21 @@ public static void Feedback()
                 }
 
                 Assert.Equal(2, slow.History.Count);
-                Assert.Equal(history[0], slow.History[0]);
-                Assert.Equal(history[1], slow.History[1]);
+                Assert.Equal($"{client}-{history[0]}", slow.History[0]);
+                Assert.Equal($"{client}-{history[1]}", slow.History[1]);
 
                 Assert.Equal(2, fast.History.Count);
-                Assert.Equal(history[0], fast.History[0]);
-                Assert.Equal(history[1], fast.History[1]);
+                Assert.Equal($"{client}-{history[0]}", fast.History[0]);
+                Assert.Equal($"{client}-{history[1]}", fast.History[1]);
+
+                Assert.Single(slow.DisplayedSuggestions);
+                Assert.Equal($"{session}-2", slow.DisplayedSuggestions[0]);
+
+                Assert.Single(fast.DisplayedSuggestions);
+                Assert.Equal($"{session}--1", fast.DisplayedSuggestions[0]);
 
                 Assert.Single(slow.AcceptedSuggestions);
-                Assert.Equal("Yeah", slow.AcceptedSuggestions[0]);
+                Assert.Equal($"{session}-Yeah", slow.AcceptedSuggestions[0]);
 
                 Assert.Empty(fast.AcceptedSuggestions);
             }
diff --git a/test/xUnit/csharp/test_Subsystem.cs b/test/xUnit/csharp/test_Subsystem.cs
index a45ebc116b5..867a1dd9ff3 100644
--- a/test/xUnit/csharp/test_Subsystem.cs
+++ b/test/xUnit/csharp/test_Subsystem.cs
@@ -95,10 +95,12 @@ public static void RegisterSubsystem()
                 Assert.Null(impl.FunctionsToDefine);
                 Assert.Equal(SubsystemKind.CommandPredictor, impl.Kind);
 
-                var predCxt = PredictionContext.Create("Hello world");
-                var results = impl.GetSuggestion(predCxt, CancellationToken.None);
-                Assert.Equal($"Hello world TEST-1 from {impl.Name}", results[0].SuggestionText);
-                Assert.Equal($"Hello world TeSt-2 from {impl.Name}", results[1].SuggestionText);
+                const string client = "SubsystemTest";
+                const string input = "Hello world";
+                var predCxt = PredictionContext.Create(input);
+                var results = impl.GetSuggestion(client, predCxt, CancellationToken.None);
+                Assert.Equal($"'{input}' from '{client}' - TEST-1 from {impl.Name}", results.SuggestionEntries[0].SuggestionText);
+                Assert.Equal($"'{input}' from '{client}' - TeSt-2 from {impl.Name}", results.SuggestionEntries[1].SuggestionText);
 
                 // Now validate the all-subsystem-implementation collection.
                 ReadOnlyCollection<ICommandPredictor> impls = SubsystemManager.GetSubsystems<ICommandPredictor>();

From bea03e397197cfec1a112e76ae071033a65a4408 Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Fri, 22 Jan 2021 10:52:02 -0800
Subject: [PATCH 7/9] Address codefactor issues

---
 test/xUnit/csharp/test_Prediction.cs | 57 ++++++++++++++--------------
 test/xUnit/csharp/test_Subsystem.cs  | 12 +++---
 2 files changed, 35 insertions(+), 34 deletions(-)

diff --git a/test/xUnit/csharp/test_Prediction.cs b/test/xUnit/csharp/test_Prediction.cs
index a034a6b77f1..8febad1752f 100644
--- a/test/xUnit/csharp/test_Prediction.cs
+++ b/test/xUnit/csharp/test_Prediction.cs
@@ -90,7 +90,8 @@ public SuggestionPackage GetSuggestion(string clientId, PredictionContext contex
 
             // You can get the user input from the AST.
             var userInput = context.InputAst.Extent.Text;
-            var entries = new List<PredictiveSuggestion> {
+            var entries = new List<PredictiveSuggestion>
+            {
                 new PredictiveSuggestion($"'{userInput}' from '{clientId}' - TEST-1 from {Name}"),
                 new PredictiveSuggestion($"'{userInput}' from '{clientId}' - TeSt-2 from {Name}"),
             };
@@ -101,19 +102,19 @@ public SuggestionPackage GetSuggestion(string clientId, PredictionContext contex
 
     public static class CommandPredictionTests
     {
-        private const string client = "PredictionTest";
-        private const uint session = 56;
+        private const string Client = "PredictionTest";
+        private const uint Session = 56;
 
         [Fact]
         public static void PredictInput()
         {
-            const string input = "Hello world";
+            const string Input = "Hello world";
             MyPredictor slow = MyPredictor.SlowPredictor;
             MyPredictor fast = MyPredictor.FastPredictor;
-            Ast ast = Parser.ParseInput(input, out Token[] tokens, out _);
+            Ast ast = Parser.ParseInput(Input, out Token[] tokens, out _);
 
             // Returns null when no predictor implementation registered
-            List<PredictionResult> results = CommandPrediction.PredictInput(client, ast, tokens).Result;
+            List<PredictionResult> results = CommandPrediction.PredictInput(Client, ast, tokens).Result;
             Assert.Null(results);
 
             try
@@ -126,35 +127,35 @@ public static void PredictInput()
                 // cannot finish before the specified timeout.
                 // The specified timeout is exaggerated to make the test reliable.
                 // xUnit must spin up a lot tasks, which makes the test unreliable when the time difference between 'delay' and 'timeout' is small.
-                results = CommandPrediction.PredictInput(client, ast, tokens, millisecondsTimeout: 1000).Result;
+                results = CommandPrediction.PredictInput(Client, ast, tokens, millisecondsTimeout: 1000).Result;
                 Assert.Single(results);
 
                 PredictionResult res = results[0];
                 Assert.Equal(fast.Id, res.Id);
-                Assert.Equal(session, res.Session);
+                Assert.Equal(Session, res.Session);
                 Assert.Equal(2, res.Suggestions.Count);
-                Assert.Equal($"'{input}' from '{client}' - TEST-1 from {fast.Name}", res.Suggestions[0].SuggestionText);
-                Assert.Equal($"'{input}' from '{client}' - TeSt-2 from {fast.Name}", res.Suggestions[1].SuggestionText);
+                Assert.Equal($"'{Input}' from '{Client}' - TEST-1 from {fast.Name}", res.Suggestions[0].SuggestionText);
+                Assert.Equal($"'{Input}' from '{Client}' - TeSt-2 from {fast.Name}", res.Suggestions[1].SuggestionText);
 
                 // Expect the results from both 'slow' and 'fast' predictors
                 // Same here -- the specified timeout is exaggerated to make the test reliable.
                 // xUnit must spin up a lot tasks, which makes the test unreliable when the time difference between 'delay' and 'timeout' is small.
-                results = CommandPrediction.PredictInput(client, ast, tokens, millisecondsTimeout: 4000).Result;
+                results = CommandPrediction.PredictInput(Client, ast, tokens, millisecondsTimeout: 4000).Result;
                 Assert.Equal(2, results.Count);
 
                 PredictionResult res1 = results[0];
                 Assert.Equal(slow.Id, res1.Id);
-                Assert.Equal(session, res1.Session);
+                Assert.Equal(Session, res1.Session);
                 Assert.Equal(2, res1.Suggestions.Count);
-                Assert.Equal($"'{input}' from '{client}' - TEST-1 from {slow.Name}", res1.Suggestions[0].SuggestionText);
-                Assert.Equal($"'{input}' from '{client}' - TeSt-2 from {slow.Name}", res1.Suggestions[1].SuggestionText);
+                Assert.Equal($"'{Input}' from '{Client}' - TEST-1 from {slow.Name}", res1.Suggestions[0].SuggestionText);
+                Assert.Equal($"'{Input}' from '{Client}' - TeSt-2 from {slow.Name}", res1.Suggestions[1].SuggestionText);
 
                 PredictionResult res2 = results[1];
                 Assert.Equal(fast.Id, res2.Id);
-                Assert.Equal(session, res2.Session);
+                Assert.Equal(Session, res2.Session);
                 Assert.Equal(2, res2.Suggestions.Count);
-                Assert.Equal($"'{input}' from '{client}' - TEST-1 from {fast.Name}", res2.Suggestions[0].SuggestionText);
-                Assert.Equal($"'{input}' from '{client}' - TeSt-2 from {fast.Name}", res2.Suggestions[1].SuggestionText);
+                Assert.Equal($"'{Input}' from '{Client}' - TEST-1 from {fast.Name}", res2.Suggestions[0].SuggestionText);
+                Assert.Equal($"'{Input}' from '{Client}' - TeSt-2 from {fast.Name}", res2.Suggestions[1].SuggestionText);
             }
             finally
             {
@@ -178,10 +179,10 @@ public static void Feedback()
                 var history = new[] { "hello", "world" };
                 var ids = new HashSet<Guid> { slow.Id, fast.Id };
 
-                CommandPrediction.OnCommandLineAccepted(client, history);
-                CommandPrediction.OnSuggestionDisplayed(slow.Id, session, 2);
-                CommandPrediction.OnSuggestionDisplayed(fast.Id, session, -1);
-                CommandPrediction.OnSuggestionAccepted(slow.Id, session, "Yeah");
+                CommandPrediction.OnCommandLineAccepted(Client, history);
+                CommandPrediction.OnSuggestionDisplayed(slow.Id, Session, 2);
+                CommandPrediction.OnSuggestionDisplayed(fast.Id, Session, -1);
+                CommandPrediction.OnSuggestionAccepted(slow.Id, Session, "Yeah");
 
                 // The calls to 'StartEarlyProcessing' and 'OnSuggestionAccepted' are queued in thread pool,
                 // so we wait a bit to make sure the calls are done.
@@ -191,21 +192,21 @@ public static void Feedback()
                 }
 
                 Assert.Equal(2, slow.History.Count);
-                Assert.Equal($"{client}-{history[0]}", slow.History[0]);
-                Assert.Equal($"{client}-{history[1]}", slow.History[1]);
+                Assert.Equal($"{Client}-{history[0]}", slow.History[0]);
+                Assert.Equal($"{Client}-{history[1]}", slow.History[1]);
 
                 Assert.Equal(2, fast.History.Count);
-                Assert.Equal($"{client}-{history[0]}", fast.History[0]);
-                Assert.Equal($"{client}-{history[1]}", fast.History[1]);
+                Assert.Equal($"{Client}-{history[0]}", fast.History[0]);
+                Assert.Equal($"{Client}-{history[1]}", fast.History[1]);
 
                 Assert.Single(slow.DisplayedSuggestions);
-                Assert.Equal($"{session}-2", slow.DisplayedSuggestions[0]);
+                Assert.Equal($"{Session}-2", slow.DisplayedSuggestions[0]);
 
                 Assert.Single(fast.DisplayedSuggestions);
-                Assert.Equal($"{session}--1", fast.DisplayedSuggestions[0]);
+                Assert.Equal($"{Session}--1", fast.DisplayedSuggestions[0]);
 
                 Assert.Single(slow.AcceptedSuggestions);
-                Assert.Equal($"{session}-Yeah", slow.AcceptedSuggestions[0]);
+                Assert.Equal($"{Session}-Yeah", slow.AcceptedSuggestions[0]);
 
                 Assert.Empty(fast.AcceptedSuggestions);
             }
diff --git a/test/xUnit/csharp/test_Subsystem.cs b/test/xUnit/csharp/test_Subsystem.cs
index 867a1dd9ff3..f2ca308221f 100644
--- a/test/xUnit/csharp/test_Subsystem.cs
+++ b/test/xUnit/csharp/test_Subsystem.cs
@@ -95,12 +95,12 @@ public static void RegisterSubsystem()
                 Assert.Null(impl.FunctionsToDefine);
                 Assert.Equal(SubsystemKind.CommandPredictor, impl.Kind);
 
-                const string client = "SubsystemTest";
-                const string input = "Hello world";
-                var predCxt = PredictionContext.Create(input);
-                var results = impl.GetSuggestion(client, predCxt, CancellationToken.None);
-                Assert.Equal($"'{input}' from '{client}' - TEST-1 from {impl.Name}", results.SuggestionEntries[0].SuggestionText);
-                Assert.Equal($"'{input}' from '{client}' - TeSt-2 from {impl.Name}", results.SuggestionEntries[1].SuggestionText);
+                const string Client = "SubsystemTest";
+                const string Input = "Hello world";
+                var predCxt = PredictionContext.Create(Input);
+                var results = impl.GetSuggestion(Client, predCxt, CancellationToken.None);
+                Assert.Equal($"'{Input}' from '{Client}' - TEST-1 from {impl.Name}", results.SuggestionEntries[0].SuggestionText);
+                Assert.Equal($"'{Input}' from '{Client}' - TeSt-2 from {impl.Name}", results.SuggestionEntries[1].SuggestionText);
 
                 // Now validate the all-subsystem-implementation collection.
                 ReadOnlyCollection<ICommandPredictor> impls = SubsystemManager.GetSubsystems<ICommandPredictor>();

From 6bf5817920317a6dffe198b3039b17e78d9b69b5 Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Thu, 28 Jan 2021 13:05:43 -0800
Subject: [PATCH 8/9] Pass 'ClientId' to 'OnSuggestionDisplay' and
 'OnSuggestionAccepted' and also make 'Session' use 'uint?' type

---
 .../CommandPrediction/CommandPrediction.cs    | 15 ++++++-----
 .../CommandPrediction/ICommandPredictor.cs    | 25 ++++++++++++++++---
 .../engine/Utils.cs                           |  8 ++++++
 test/xUnit/csharp/test_Prediction.cs          | 20 +++++++--------
 4 files changed, 48 insertions(+), 20 deletions(-)

diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
index b0c15cb123d..edc8fb272a2 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/CommandPrediction.cs
@@ -29,15 +29,16 @@ public sealed class PredictionResult
 
         /// <summary>
         /// Gets the mini-session id that represents a specific invocation to the <see cref="ICommandPredictor.GetSuggestion"/> API of the predictor.
+        /// When it's not specified, it's considered by a client that the predictor doesn't expect feedback.
         /// </summary>
-        public uint Session { get; }
+        public uint? Session { get; }
 
         /// <summary>
         /// Gets the suggestions.
         /// </summary>
         public IReadOnlyList<PredictiveSuggestion> Suggestions { get; }
 
-        internal PredictionResult(Guid id, string name, uint session, List<PredictiveSuggestion> suggestions)
+        internal PredictionResult(Guid id, string name, uint? session, List<PredictiveSuggestion> suggestions)
         {
             Id = id;
             Name = name;
@@ -153,13 +154,14 @@ public static void OnCommandLineAccepted(string client, IReadOnlyList<string> hi
         /// <summary>
         /// Send feedback to a predictor when one or more suggestions from it were displayed to the user.
         /// </summary>
+        /// <param name="client">Represents the client that initiates the call.</param>
         /// <param name="predictorId">The identifier of the predictor whose prediction result was accepted.</param>
         /// <param name="session">The mini-session where the displayed suggestions came from.</param>
         /// <param name="countOrIndex">
         /// When the value is greater than 0, it's the number of displayed suggestions from the list returned in <paramref name="session"/>, starting from the index 0.
         /// When the value is less than or equal to 0, it means a single suggestion from the list got displayed, and the index is the absolute value.
         /// </param>
-        public static void OnSuggestionDisplayed(Guid predictorId, uint session, int countOrIndex)
+        public static void OnSuggestionDisplayed(string client, Guid predictorId, uint session, int countOrIndex)
         {
             var predictors = SubsystemManager.GetSubsystems<ICommandPredictor>();
             if (predictors.Count == 0)
@@ -172,7 +174,7 @@ public static void OnSuggestionDisplayed(Guid predictorId, uint session, int cou
                 if (predictor.AcceptFeedback && predictor.Id == predictorId)
                 {
                     ThreadPool.QueueUserWorkItem<ICommandPredictor>(
-                        state => state.OnSuggestionDisplayed(session, countOrIndex),
+                        state => state.OnSuggestionDisplayed(client, session, countOrIndex),
                         predictor,
                         preferLocal: false);
                 }
@@ -182,10 +184,11 @@ public static void OnSuggestionDisplayed(Guid predictorId, uint session, int cou
         /// <summary>
         /// Send feedback to a predictor when a suggestion from it was accepted.
         /// </summary>
+        /// <param name="client">Represents the client that initiates the call.</param>
         /// <param name="predictorId">The identifier of the predictor whose prediction result was accepted.</param>
         /// <param name="session">The mini-session where the accepted suggestion came from.</param>
         /// <param name="suggestionText">The accepted suggestion text.</param>
-        public static void OnSuggestionAccepted(Guid predictorId, uint session, string suggestionText)
+        public static void OnSuggestionAccepted(string client, Guid predictorId, uint session, string suggestionText)
         {
             Requires.NotNullOrEmpty(suggestionText, nameof(suggestionText));
 
@@ -200,7 +203,7 @@ public static void OnSuggestionAccepted(Guid predictorId, uint session, string s
                 if (predictor.AcceptFeedback && predictor.Id == predictorId)
                 {
                     ThreadPool.QueueUserWorkItem<ICommandPredictor>(
-                        state => state.OnSuggestionAccepted(session, suggestionText),
+                        state => state.OnSuggestionAccepted(client, session, suggestionText),
                         predictor,
                         preferLocal: false);
                 }
diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
index 37c98c7fb48..3b8b6d5a8d7 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
@@ -56,19 +56,21 @@ public interface ICommandPredictor : ISubsystem
         /// <summary>
         /// One or more suggestions provided by the predictor were displayed to the user.
         /// </summary>
+        /// <param name="clientId">Represents the client that initiates the call.</param>
         /// <param name="session">The mini-session where the displayed suggestions came from.</param>
         /// <param name="countOrIndex">
         /// When the value is greater than 0, it's the number of displayed suggestions from the list returned in <paramref name="session"/>, starting from the index 0.
         /// When the value is less than or equal to 0, it means a single suggestion from the list got displayed, and the index is the absolute value.
         /// </param>
-        void OnSuggestionDisplayed(uint session, int countOrIndex);
+        void OnSuggestionDisplayed(string clientId, uint session, int countOrIndex);
 
         /// <summary>
         /// The suggestion provided by the predictor was accepted.
         /// </summary>
+        /// <param name="clientId">Represents the client that initiates the call.</param>
         /// <param name="session">Represents the mini-session where the accepted suggestion came from.</param>
         /// <param name="acceptedSuggestion">The accepted suggestion text.</param>
-        void OnSuggestionAccepted(uint session, string acceptedSuggestion);
+        void OnSuggestionAccepted(string clientId, uint session, string acceptedSuggestion);
     }
 
     /// <summary>
@@ -181,8 +183,9 @@ public struct SuggestionPackage
     {
         /// <summary>
         /// Gets the mini-session that represents a specific invocation to <see cref="ICommandPredictor.GetSuggestion"/>.
+        /// When it's not specified, it's considered by a client that the predictor doesn't expect feedback.
         /// </summary>
-        public uint Session { get; }
+        public uint? Session { get; }
 
         /// <summary>
         /// Gets the suggestion entries returned from that mini-session.
@@ -190,12 +193,26 @@ public struct SuggestionPackage
         public List<PredictiveSuggestion>? SuggestionEntries { get; }
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="SuggestionPackage"/> struct.
+        /// Initializes a new instance of the <see cref="SuggestionPackage"/> struct without providing a session id.
+        /// </summary>
+        /// <param name="suggestionEntries">The suggestions to return.</param>
+        public SuggestionPackage(List<PredictiveSuggestion> suggestionEntries)
+        {
+            Requires.NotNullOrEmpty(suggestionEntries, nameof(suggestionEntries));
+
+            Session = null;
+            SuggestionEntries = suggestionEntries;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SuggestionPackage"/> struct with the mini-session id and the suggestions.
         /// </summary>
         /// <param name="session">The mini-session where suggestions came from.</param>
         /// <param name="suggestionEntries">The suggestions to return.</param>
         public SuggestionPackage(uint session, List<PredictiveSuggestion> suggestionEntries)
         {
+            Requires.NotNullOrEmpty(suggestionEntries, nameof(suggestionEntries));
+
             Session = session;
             SuggestionEntries = suggestionEntries;
         }
diff --git a/src/System.Management.Automation/engine/Utils.cs b/src/System.Management.Automation/engine/Utils.cs
index 6a4a863d23c..fa1ef13572e 100644
--- a/src/System.Management.Automation/engine/Utils.cs
+++ b/src/System.Management.Automation/engine/Utils.cs
@@ -2312,6 +2312,14 @@ internal static void NotNullOrEmpty(string value, string paramName)
             }
         }
 
+        internal static void NotNullOrEmpty(ICollection value, string paramName)
+        {
+            if (value == null || value.Count == 0)
+            {
+                throw new ArgumentNullException(paramName);
+            }
+        }
+
         internal static void Condition([DoesNotReturnIf(false)] bool precondition, string paramName)
         {
             if (!precondition)
diff --git a/test/xUnit/csharp/test_Prediction.cs b/test/xUnit/csharp/test_Prediction.cs
index 8febad1752f..8f018ebb9e1 100644
--- a/test/xUnit/csharp/test_Prediction.cs
+++ b/test/xUnit/csharp/test_Prediction.cs
@@ -69,14 +69,14 @@ public void StartEarlyProcessing(string clientId, IReadOnlyList<string> history)
             }
         }
 
-        public void OnSuggestionDisplayed(uint session, int countOrIndex)
+        public void OnSuggestionDisplayed(string clientId, uint session, int countOrIndex)
         {
-            DisplayedSuggestions.Add($"{session}-{countOrIndex}");
+            DisplayedSuggestions.Add($"{clientId}-{session}-{countOrIndex}");
         }
 
-        public void OnSuggestionAccepted(uint session, string acceptedSuggestion)
+        public void OnSuggestionAccepted(string clientId, uint session, string acceptedSuggestion)
         {
-            AcceptedSuggestions.Add($"{session}-{acceptedSuggestion}");
+            AcceptedSuggestions.Add($"{clientId}-{session}-{acceptedSuggestion}");
         }
 
         public SuggestionPackage GetSuggestion(string clientId, PredictionContext context, CancellationToken cancellationToken)
@@ -180,9 +180,9 @@ public static void Feedback()
                 var ids = new HashSet<Guid> { slow.Id, fast.Id };
 
                 CommandPrediction.OnCommandLineAccepted(Client, history);
-                CommandPrediction.OnSuggestionDisplayed(slow.Id, Session, 2);
-                CommandPrediction.OnSuggestionDisplayed(fast.Id, Session, -1);
-                CommandPrediction.OnSuggestionAccepted(slow.Id, Session, "Yeah");
+                CommandPrediction.OnSuggestionDisplayed(Client, slow.Id, Session, 2);
+                CommandPrediction.OnSuggestionDisplayed(Client, fast.Id, Session, -1);
+                CommandPrediction.OnSuggestionAccepted(Client, slow.Id, Session, "Yeah");
 
                 // The calls to 'StartEarlyProcessing' and 'OnSuggestionAccepted' are queued in thread pool,
                 // so we wait a bit to make sure the calls are done.
@@ -200,13 +200,13 @@ public static void Feedback()
                 Assert.Equal($"{Client}-{history[1]}", fast.History[1]);
 
                 Assert.Single(slow.DisplayedSuggestions);
-                Assert.Equal($"{Session}-2", slow.DisplayedSuggestions[0]);
+                Assert.Equal($"{Client}-{Session}-2", slow.DisplayedSuggestions[0]);
 
                 Assert.Single(fast.DisplayedSuggestions);
-                Assert.Equal($"{Session}--1", fast.DisplayedSuggestions[0]);
+                Assert.Equal($"{Client}-{Session}--1", fast.DisplayedSuggestions[0]);
 
                 Assert.Single(slow.AcceptedSuggestions);
-                Assert.Equal($"{Session}-Yeah", slow.AcceptedSuggestions[0]);
+                Assert.Equal($"{Client}-{Session}-Yeah", slow.AcceptedSuggestions[0]);
 
                 Assert.Empty(fast.AcceptedSuggestions);
             }

From 0b7e42d09bf49ecf72bfa8eb6a08331c54a2ab75 Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Sat, 30 Jan 2021 21:18:17 -0800
Subject: [PATCH 9/9] Add the API xml document files to the generated NuGet
 packages

---
 .../CommandPrediction/ICommandPredictor.cs    |  1 +
 tools/packaging/packaging.psm1                | 25 +++++++++++++------
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
index 3b8b6d5a8d7..d55d37a90df 100644
--- a/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
+++ b/src/System.Management.Automation/engine/Subsystem/CommandPrediction/ICommandPredictor.cs
@@ -194,6 +194,7 @@ public struct SuggestionPackage
 
         /// <summary>
         /// Initializes a new instance of the <see cref="SuggestionPackage"/> struct without providing a session id.
+        /// Note that, when a session id is not specified, it's considered by a client that the predictor doesn't expect feedback.
         /// </summary>
         /// <param name="suggestionEntries">The suggestions to return.</param>
         public SuggestionPackage(List<PredictiveSuggestion> suggestionEntries)
diff --git a/tools/packaging/packaging.psm1 b/tools/packaging/packaging.psm1
index 3d996f338aa..548f724caec 100644
--- a/tools/packaging/packaging.psm1
+++ b/tools/packaging/packaging.psm1
@@ -2036,24 +2036,27 @@ function CopyReferenceAssemblies
     switch ($assemblyName) {
         { $_ -in $supportedRefList } {
             $refDll = Join-Path -Path $refBinPath -ChildPath "$assemblyName.dll"
-            Copy-Item $refDll -Destination $refNugetPath -Force
-            Write-Log "Copied file $refDll to $refNugetPath"
+            $refDoc = Join-Path -Path $refBinPath -ChildPath "$assemblyName.xml"
+            Copy-Item $refDll, $refDoc -Destination $refNugetPath -Force
+            Write-Log "Copied file '$refDll' and '$refDoc' to '$refNugetPath'"
         }
 
         "Microsoft.PowerShell.SDK" {
             foreach ($asmFileName in $assemblyFileList) {
                 $refFile = Join-Path -Path $refBinPath -ChildPath $asmFileName
                 if (Test-Path -Path $refFile) {
-                    Copy-Item $refFile -Destination $refNugetPath -Force
-                    Write-Log "Copied file $refFile to $refNugetPath"
+                    $refDoc = Join-Path -Path $refBinPath -ChildPath ([System.IO.Path]::ChangeExtension($asmFileName, "xml"))
+                    Copy-Item $refFile, $refDoc -Destination $refNugetPath -Force
+                    Write-Log "Copied file '$refFile' and '$refDoc' to '$refNugetPath'"
                 }
             }
         }
 
         default {
             $ref_SMA = Join-Path -Path $refBinPath -ChildPath System.Management.Automation.dll
-            Copy-Item $ref_SMA -Destination $refNugetPath -Force
-            Write-Log "Copied file $ref_SMA to $refNugetPath"
+            $ref_doc = Join-Path -Path $refBinPath -ChildPath System.Management.Automation.xml
+            Copy-Item $ref_SMA, $ref_doc -Destination $refNugetPath -Force
+            Write-Log "Copied file '$ref_SMA' and '$ref_doc' to '$refNugetPath'"
         }
     }
 }
@@ -2235,8 +2238,13 @@ function New-ReferenceAssembly
             throw "$assemblyName.dll was not found at: $Linux64BinPath"
         }
 
+        $dllXmlDoc = Join-Path $Linux64BinPath "$assemblyName.xml"
+        if (-not (Test-Path $dllXmlDoc)) {
+            throw "$assemblyName.xml was not found at: $Linux64BinPath"
+        }
+
         $genAPIArgs = "$linuxDllPath","-libPath:$Linux64BinPath,$Linux64BinPath\ref"
-        Write-Log "GenAPI cmd: $genAPIExe $genAPIArgsString"
+        Write-Log "GenAPI cmd: $genAPIExe $genAPIArgs"
 
         Start-NativeExecution { & $genAPIExe $genAPIArgs } | Out-File $generatedSource -Force
         Write-Log "Reference assembly file generated at: $generatedSource"
@@ -2268,6 +2276,9 @@ function New-ReferenceAssembly
             Copy-Item $refBinPath $RefAssemblyDestinationPath -Force
             Write-Log "Reference assembly '$assemblyName.dll' built and copied to $RefAssemblyDestinationPath"
 
+            Copy-Item $dllXmlDoc $RefAssemblyDestinationPath -Force
+            Write-Log "Xml document '$assemblyName.xml' copied to $RefAssemblyDestinationPath"
+
             if ($assemblyName -eq "System.Management.Automation") {
                 $SMAReferenceAssembly = $refBinPath
             }