With a file App.js that looks like: import * as React from "react"; import { render } from "react-dom"; const App = () => { return (

hello

); }; render(, document.getElementById("root")); If you open the file in JS mode (Emacs 27), and move point inside of "abc", calling M-: (c-beginning-of-defun) gives the following error: Debugger entered--Lisp error: (wrong-type-argument hash-table-p nil) copy-hash-table(nil) c-forward-<>-arglist(nil) c-backward-<>-arglist(nil nil) c-looking-at-decl-block(99 nil) c-most-enclosing-decl-block((117 99 88 (40 . 50))) c-widen-to-enclosing-decl-scope((117 99 88 (40 . 50)) 1 234) c-beginning-of-defun() eval((c-beginning-of-defun) t) eval-expression((c-beginning-of-defun) nil nil 127) funcall-interactively(eval-expression (c-beginning-of-defun) nil nil 127) call-interactively(eval-expression nil nil) command-execute(eval-expression) Manually invoking C-M-a inside the double quotes should end the same way. In GNU Emacs 27.0.91 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.20) Windowing system distributor 'The X.Org Foundation', version 11.0.12008000 System Description: NixOS 20.09 (Nightingale)