nodejs, javascript indentation for emacs

init.el

;; Add this to your Emacs configuration to have proper Nodejs
;; indentation with javascript when using `js-mode'. —Travis Jeffery
(add-hook 'js-mode-hook (lambda ()  
                          (defun js--proper-indentation (parse-status)
                            "Return the proper indentation for the current line."
                            (save-excursion
                              (back-to-indentation)
                              (cond
                               ((looking-at ",")
                                (let ((spos
                                       (save-excursion
                                         (while (looking-back "}[\t\n ]*")
                                           (backward-sexp)
                                           (if (looking-back ",[\t\n ]*")
                                               (re-search-backward ",[\t\n ]*")))

                                         (cond
                                          ((looking-back "\\(,\\|(\\)[ \t]*\\<\\([^:=\n\t ]+\\)[ \t\n]*")
                                           (re-search-backward "\\(,\\|(\\)[ \t]*\\<\\([^:=\n\t ]+\\)[ \t\n]*" (point-min) t)
                                           (+ (current-column) 2))

                                          ((re-search-backward "\\<\\([^:=\n\t ]+\\)[ \t]*\\(:\\|=\\)" (point-min) t)
                                           (current-column))
                                          (t 
                                           nil)))))
                                  (if spos
                                      (- spos 2)
                                    (+ js-indent-level js-expr-indent-offset))))
                               ((nth 4 parse-status)
                                (js--get-c-offset 'c (nth 8 parse-status)))
                               ((nth 8 parse-status) 0) ; inside string
                               ((js--ctrl-statement-indentation))
                               ((eq (char-after) ?#) 0)
                               ((save-excursion (js--beginning-of-macro)) 4)
                               ((nth 1 parse-status)
                                ;; A single closing paren/bracket should be indented at the
                                ;; same level as the opening statement. Same goes for
                                ;; "case" and "default".
                                (let ((same-indent-p (looking-at
                                                      "[]})]\\|\\_<case\\_>\\|\\_<default\\_>"))
                                      (continued-expr-p (js--continued-expression-p)))
                                  (goto-char (nth 1 parse-status)) ; go to the opening char
                                  (if (looking-at "[({[]\\s-*\\(/[/*]\\|$\\)")
                                      (progn ; nothing following the opening paren/bracket
                                        (skip-syntax-backward " ")
                                        (when (eq (char-before) ?\)) (backward-list))
                                        (back-to-indentation)
                                        (cond (same-indent-p
                                               (current-column))
                                              (continued-expr-p
                                               (+ (current-column) (* 2 js-indent-level)
                                                  js-expr-indent-offset))
                                              (t
                                               (+ (current-column) js-indent-level
                                                  (case (char-after (nth 1 parse-status))
                                                    (?\( js-paren-indent-offset)
                                                    (?\[ js-square-indent-offset)
                                                    (?\{ js-curly-indent-offset))))))
                                    ;; If there is something following the opening
                                    ;; paren/bracket, everything else should be indented at
                                    ;; the same level.
                                    (unless same-indent-p
                                      (forward-char)
                                      (skip-chars-forward " \t"))
                                    (current-column))))

                               ((js--continued-expression-p)
                                (+ js-indent-level js-expr-indent-offset))
                               (t 0))))))