WIP-semantic in session based TS

Author: orta

src/server/protocol.ts

@@ -861,6 +861,11 @@ namespace ts.server.protocol {
          * Length of the span.
          */
         length: number;
+        /**
+         * Optional parameter for the semantic highlighting response, if absent it
+         * defaults to "original".
+         */
+        format?: "original" | "2020"
     }
 
     /**

src/server/session.ts

@@ -1115,7 +1115,8 @@ namespace ts.server {
 
         private getEncodedSemanticClassifications(args: protocol.EncodedSemanticClassificationsRequestArgs) {
             const { file, project } = this.getFileAndProject(args);
-            return project.getLanguageService().getEncodedSemanticClassifications(file, args);
+            const format = args.format === "2020" ? SemanticClassificationFormat.TwentyTwenty : SemanticClassificationFormat.Original;
+            return project.getLanguageService().getEncodedSemanticClassifications(file, args, format);
         }
 
         private getProject(projectFileName: string | undefined): Project | undefined {

src/services/shims.ts

@@ -693,10 +693,10 @@ namespace ts {
             return realizeDiagnostics(diagnostics, newLine);
         }
 
-        public getSyntacticClassifications(fileName: string, start: number, length: number): string {
+        public getSyntacticClassifications(fileName: string, start: number, length: number, format?: SemanticClassificationFormat): string {
             return this.forwardJSONCall(
                 `getSyntacticClassifications('${fileName}', ${start}, ${length})`,
-                () => this.languageService.getSyntacticClassifications(fileName, createTextSpan(start, length))
+                () => this.languageService.getSyntacticClassifications(fileName, createTextSpan(start, length), format ||= SemanticClassificationFormat.Original)
             );
         }