Fix Failed to execute 'getWriter' on 'WritableStream': Cannot create writer when WritableStream is locked error

Author: gfwilliams

examples/uartUploadZIP.html

@@ -86,7 +86,8 @@
               // If the path ends with a slash, it's a directory, which we should create if it doesn't exist
               if (path[path.length-1]=="/") {
                 console.log("Creating directory "+path);
-                UART.getConnection().write(`\x10if (!require("fs").statSync(${JSON.stringify(path)})) require("fs").mkdir(${JSON.stringify(path)});\n`);
+                return new Promise(resolve =>
+                  UART.getConnection().write(`\x10if (!require("fs").statSync(${JSON.stringify(path)})) require("fs").mkdir(${JSON.stringify(path)});\n`, resolve));
               } else {
                 console.log("Can't restore files of length 0, ignoring "+path);
               }