add status request

src/server/protocol.ts

@@ -71,6 +71,7 @@ namespace ts.server.protocol {
         SignatureHelp = "signatureHelp",
         /* @internal */
         SignatureHelpFull = "signatureHelp-full",
+        Status = "status",
         TypeDefinition = "typeDefinition",
         ProjectInfo = "projectInfo",
         ReloadProjects = "reloadProjects",
@@ -216,6 +217,27 @@ namespace ts.server.protocol {
         projectFileName?: string;
     }
 
+    /**
+     * Requests status information from the server
+     */
+    export interface StatusRequest extends Request {
+        command: CommandTypes.Status;
+    }
+
+    export interface StatusResponseBody {
+        /**
+         * the version of the currently-running server.
+         */
+        version: string;
+    }
+
+    /**
+     * Response to StatusRequest
+     */
+    export interface StatusResponse extends Response {
+        body: StatusResponseBody;
+    }
+
     /**
      * Requests a JS Doc comment template for a given position
      */

src/server/session.ts

@@ -1703,6 +1703,10 @@ namespace ts.server {
         }
 
         private handlers = createMapFromTemplate<(request: protocol.Request) => HandlerResponse>({
+            [CommandNames.Status]: () => {
+                const response: protocol.StatusResponseBody = { version };
+                return this.requiredResponse(response);
+            },
             [CommandNames.OpenExternalProject]: (request: protocol.OpenExternalProjectRequest) => {
                 this.projectService.openExternalProject(request.arguments, /*suppressRefreshOfInferredProjects*/ false);
                 // TODO: report errors