Setup standard src, test folder structure. Add unit test project.

src/ServiceHost/LanguageServer/Diagnostics.cs

@@ -0,0 +1,71 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+
+namespace Microsoft.SqlTools.EditorServices.Protocol.LanguageServer
+{
+    public class PublishDiagnosticsNotification
+    {
+        public static readonly
+            EventType<PublishDiagnosticsNotification> Type = 
+            EventType<PublishDiagnosticsNotification>.Create("textDocument/publishDiagnostics");
+
+        /// <summary>
+        /// Gets or sets the URI for which diagnostic information is reported.
+        /// </summary>
+        public string Uri { get; set; }
+
+        /// <summary>
+        /// Gets or sets the array of diagnostic information items.
+        /// </summary>
+        public Diagnostic[] Diagnostics { get; set; }
+    }
+
+    public enum DiagnosticSeverity 
+    {
+        /// <summary>
+        /// Indicates that the diagnostic represents an error.
+        /// </summary>
+        Error = 1,
+
+        /// <summary>
+        /// Indicates that the diagnostic represents a warning.
+        /// </summary>
+        Warning = 2,
+
+        /// <summary>
+        /// Indicates that the diagnostic represents an informational message.
+        /// </summary>
+        Information = 3,
+
+        /// <summary>
+        /// Indicates that the diagnostic represents a hint.
+        /// </summary>
+        Hint = 4
+    }
+
+    public class Diagnostic
+    {
+        public Range Range { get; set; }
+
+        /// <summary>
+        /// Gets or sets the severity of the diagnostic.  If omitted, the
+        /// client should interpret the severity.
+        /// </summary>
+        public DiagnosticSeverity? Severity { get; set; }
+
+        /// <summary>
+        /// Gets or sets the diagnostic's code (optional).
+        /// </summary>
+        public string Code { get; set; }
+
+        /// <summary>
+        /// Gets or sets the diagnostic message.
+        /// </summary>
+        public string Message { get; set; }
+    }
+}
+