Fix #2 - Message types should be auto-registered

This change completes the work to have all Transport.Stdio message types
be marked with a MessageTypeNameAttribute.  This attribute specifies
the name used to identify the type in the JSON messages that are sent
between client and editor service.

The MessageTypeResolver also validates whether a message type is decorated
with an attribute and throws a debug assert if it is missing.  This helps
message type authors remember to add the attribute so that everything works
correctly.

Finally, all existing message types have been updated to follow the new
message type decoration pattern.

Author: daviwil

src/PowerShellEditorServices.Transport.Stdio/Constants.cs

@@ -4,6 +4,7 @@
 //
 
 using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
 using Newtonsoft.Json.Serialization;
 using System;
 using System.Collections.Generic;
@@ -13,13 +14,25 @@
 
 namespace Microsoft.PowerShell.EditorServices.Transport.Stdio
 {
-    public class Constants
+    public static class Constants
     {
         public const string ContentLengthString = "Content-Length: ";
+        public static readonly JsonSerializerSettings JsonSerializerSettings;
 
-        public static readonly JsonSerializerSettings JsonSerializerSettings = new JsonSerializerSettings
+        static Constants()
         {
-            ContractResolver = new CamelCasePropertyNamesContractResolver()
-        };
+            JsonSerializerSettings = new JsonSerializerSettings();
+
+            // Camel case all object properties
+            JsonSerializerSettings.ContractResolver =
+                new CamelCasePropertyNamesContractResolver();
+
+            // Convert enum values to their string representation with camel casing
+            JsonSerializerSettings.Converters.Add(
+                new StringEnumConverter
+                {
+                    CamelCaseText = true
+                });
+        }
     }
 }

src/PowerShellEditorServices.Transport.Stdio/Event/DiagnosticEvent.cs

@@ -3,21 +3,43 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
+using Microsoft.PowerShell.EditorServices.Session;
+using Microsoft.PowerShell.EditorServices.Transport.Stdio.Message;
+using System.Collections.Generic;
+
 namespace Microsoft.PowerShell.EditorServices.Transport.Stdio.Event
 {
-    public class DiagnosticEvent : EventBase<DiagnosticEventBody>
+    [MessageTypeName("syntaxDiag")]
+    public class SyntaxDiagnosticEvent : EventBase<DiagnosticEventBody>
     {
-        public DiagnosticEvent()
+        public static SyntaxDiagnosticEvent Create(
+            string filePath,
+            ScriptFileMarker[] syntaxMarkers)
         {
-            // Initialize to an identifiable uninitialized value.
-            // Could either be "syntaxDiag" or "semanticDiag"
-            // This should be replaced by the deserialization process.
-            this.EventType = "NOT_SUPPLIED";
+            return new SyntaxDiagnosticEvent
+            {
+                Body =
+                    DiagnosticEventBody.Create(
+                        filePath,
+                        syntaxMarkers)
+            };
         }
+    }
 
-        public DiagnosticEvent(string eventType)
+    [MessageTypeName("semanticDiag")]
+    public class SemanticDiagnosticEvent : EventBase<DiagnosticEventBody>
+    {
+        public static SemanticDiagnosticEvent Create(
+            string filePath,
+            ScriptFileMarker[] semanticMarkers)
         {
-            this.EventType = eventType;
+            return new SemanticDiagnosticEvent
+            {
+                Body =
+                    DiagnosticEventBody.Create(
+                        filePath,
+                        semanticMarkers)
+            };
         }
     }
 
@@ -26,6 +48,39 @@ public class DiagnosticEventBody
         public string File { get; set; }
 
         public Diagnostic[] Diagnostics { get; set; }
+
+        public static DiagnosticEventBody Create(
+            string filePath,
+            ScriptFileMarker[] diagnosticMarkers)
+        {
+            List<Diagnostic> diagnosticList = new List<Diagnostic>();
+
+            foreach (ScriptFileMarker diagnosticMarker in diagnosticMarkers)
+            {
+                diagnosticList.Add(
+                    new Diagnostic
+                    {
+                        Text = diagnosticMarker.Message,
+                        Start = new Location
+                        {
+                            Line = diagnosticMarker.Extent.StartLineNumber,
+                            Offset = diagnosticMarker.Extent.StartColumnNumber
+                        },
+                        End = new Location
+                        {
+                            Line = diagnosticMarker.Extent.EndLineNumber,
+                            Offset = diagnosticMarker.Extent.EndColumnNumber
+                        }
+                    });
+            }
+
+            return
+                new DiagnosticEventBody
+                {
+                    File = filePath,
+                    Diagnostics = diagnosticList.ToArray()
+                };
+        }
     }
 
     public class Location

src/PowerShellEditorServices.Transport.Stdio/Event/Eventbase.cs

@@ -8,7 +8,7 @@
 
 namespace Microsoft.PowerShell.EditorServices.Transport.Stdio.Event
 {
-    public abstract class EventBase<TBody> : MessageBase, IEvent
+    public abstract class EventBase<TBody> : MessageBase
     {
         [JsonProperty("event")]
         public string EventType { get; set; }
@@ -18,11 +18,12 @@ public abstract class EventBase<TBody> : MessageBase, IEvent
         internal override string PayloadType
         {
             get { return this.EventType; }
+            set { this.EventType = value; }
         }
 
         public EventBase()
         {
-            this.Type = "event";
+            this.Type = MessageType.Event;
         }
     }
 }

src/PowerShellEditorServices.Transport.Stdio/Event/IEvent.cs

@@ -3,16 +3,14 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
+using Microsoft.PowerShell.EditorServices.Transport.Stdio.Message;
 using System.Management.Automation.Host;
 
 namespace Microsoft.PowerShell.EditorServices.Transport.Stdio.Event
 {
+    [MessageTypeName("replPromptChoice")]
     public class ReplPromptChoiceEvent : EventBase<ReplPromptChoiceEventBody>
     {
-        public ReplPromptChoiceEvent()
-        {
-            this.EventType = "replPromptChoice";
-        }
     }
 
     public class ReplPromptChoiceEventBody

src/PowerShellEditorServices.Transport.Stdio/Event/ReplPromptChoiceEvent.cs

@@ -4,16 +4,14 @@
 //
 
 using Microsoft.PowerShell.EditorServices.Console;
+using Microsoft.PowerShell.EditorServices.Transport.Stdio.Message;
 using System;
 
 namespace Microsoft.PowerShell.EditorServices.Transport.Stdio.Event
 {
+    [MessageTypeName("replWriteOutput")]
     public class ReplWriteOutputEvent : EventBase<ReplWriteOutputEventBody>
     {
-        public ReplWriteOutputEvent()
-        {
-            this.EventType = "replWriteOutput";
-        }
     }
 
     public class ReplWriteOutputEventBody

src/PowerShellEditorServices.Transport.Stdio/Event/ReplWriteOutputEvent.cs

@@ -3,13 +3,12 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
+using Microsoft.PowerShell.EditorServices.Transport.Stdio.Message;
+
 namespace Microsoft.PowerShell.EditorServices.Transport.Stdio.Event
 {
+    [MessageTypeName("started")]
     public class StartedEvent : EventBase<object>
     {
-        public StartedEvent()
-        {
-            this.EventType = "started";
-        }
     }
 }

src/PowerShellEditorServices.Transport.Stdio/Event/StartedEvent.cs

@@ -3,13 +3,16 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 //
 
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+
 namespace Microsoft.PowerShell.EditorServices.Transport.Stdio.Message
 {
     /// <summary>
     /// Provides the base class for all message types in the 
     /// standard I/O protocol.
     /// </summary>
-    public abstract class MessageBase : IMessage
+    public abstract class MessageBase
     {
         /// <summary>
         /// Gets or sets the sequence identifier for this message.
@@ -19,13 +22,13 @@ public abstract class MessageBase : IMessage
         /// <summary>
         /// Gets or sets the string identifying the type of this message.
         /// </summary>
-        public string Type { get; set; }
+        public MessageType Type { get; set; }
 
         /// <summary>
-        /// Gets the payload type name of this message.  Subclasses
+        /// Gets or sets the payload type name of this message.  Subclasses
         /// will use this to generalize access to the property that
         /// identifies its protocol payload type.
         /// </summary>
-        internal abstract string PayloadType { get; }
+        internal abstract string PayloadType { get; set;  }
     }
 }