Automatically configure tsc output and provide a new 'diagnosticStyle' option.

src/compiler/commandLineParser.ts

@@ -56,6 +56,14 @@ namespace ts {
             category: Diagnostics.Command_line_Options,
             description: Diagnostics.Stylize_errors_and_messages_using_color_and_context_experimental
         },
+    {
+        name: "diagnosticStyle",
+        type: createMapFromTemplate({
+            auto: DiagnosticStyle.Auto,
+            pretty: DiagnosticStyle.Pretty,
+            simple: DiagnosticStyle.Simple,
+        }),
+    },
         {
             name: "preserveWatchOutput",
             type: "boolean",