Make filter-regex for cider-browse-spec-all optional

It's tedious to call `(cider-browse-spec-all "")` each time.

Author: Tianxiang Xiong

cider-browse-spec.el

@@ -297,17 +297,19 @@ a more user friendly representation of SPEC-FORM."
 (defun cider-browse-spec (spec)
   "Start a new navigation and browse to SPEC definition."
   (interactive (list (completing-read "Browse spec: "
-                                      (cider-sync-request:spec-list "")
+                                      (cider-sync-request:spec-list)
                                       nil nil
                                       (cider-symbol-at-point))))
   (cider-browse-spec--clear-nav-history)
   (cider-browse-spec--browse spec))
 
 
 ;;;###autoload
-(defun cider-browse-spec-all (filter-regex)
+(defun cider-browse-spec-all (&optional filter-regex)
   "List all loaded specs in BUFFER filtered by FILTER-REGEX.
-If FILTER-REGEX is empty, list all specs in the registry."
+
+Optional argument FILTER-REGEX is a regexp string matching spec names.  The
+default value, \"\", matches all specs in the registry."
   (interactive (list (read-string "Filter regex: ")))
   (with-current-buffer (cider-popup-buffer cider-browse-spec-buffer t)
     (let ((specs (cider-sync-request:spec-list filter-regex)))
@@ -335,7 +337,7 @@ If FILTER-REGEX is empty, list all specs in the registry."
            (cider-browse-spec-all (cl-second (pop cider-browse-spec-navigation)))
          (cider-browse-spec--browse (pop cider-browse-spec-navigation))))
     (unless (cider-browse-spec--is-nav-searchp (cl-first cider-browse-spec-navigation))
-      (cider-browse-spec-all ""))))
+      (cider-browse-spec-all))))
 
 (defun cider-browse-spec-handle-mouse (event)
   "Handle mouse click EVENT."

cider-client.el

@@ -952,8 +952,9 @@ CONTEXT represents a completion context for compliment."
         nil
       eldoc)))
 
-(defun cider-sync-request:spec-list (filter-regex)
+(defun cider-sync-request:spec-list (&optional filter-regex)
   "Get a list of the available specs in the registry."
+  (setq filter-regex (or filter-regex ""))
   (thread-first `("op" "spec-list"
                   "filter-regex" ,filter-regex)
     (cider-nrepl-send-sync-request)