xref-js2

xref-js2 adds navigation to definitions or references to JavaScript projects in Emacs.

xref-js2 adds an xref backend for JavaScript files.

Instead of using a tag system, it relies on ag to query the codebase of a project. This might sound crazy at first, but it turns out that ag is so fast that jumping using xref-js2 is most of the time instantaneous, even on fairly large JavaScript codebases (it has been tested on 50k lines of JS code).

Because line by line regexp search has its limitations, xref-js2 does a second pass on result candidates and eliminates possible false positives using js2-mode's AST, thus giving very accurate results.

Requirements

• Emacs 25.1
• ag (the silver searcher)
• js2-mode

Installation

If you use js2-mode, M-. will be bound by js2, you might want to unbind it:

(define-key js2-mode-map (kbd "M-.") nil)

Then you need to add the xref backend:

(add-hook 'js2-mode-hook (lambda ()
  (add-hook 'xref-backend-functions #'xref-js2-xref-backend nil t)))

Keybindings

xref-js2 uses the xref, so the same keybindings and UI as other xref backends is used:

• M-. Jump to definition
• M-? Jump to references
• M-, Pop back to where M-. was last invoked

Demo

Jumping to definitions and back

Finding references