[RFC PATCH 11/14] b4: Move logic for checking arguments to a dedicated function

[Kyle Meyer <kyle@kyleam.com>]

The new -extend variant will need to do the same check.
---
 piem-b4.el | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/piem-b4.el b/piem-b4.el
index d2370124..48836eb2 100644
--- a/piem-b4.el
+++ b/piem-b4.el
@@ -127,6 +127,17 @@ (defun piem-b4-am-ready-from-mid (mid &optional args)
   (apply #'piem-process-start nil piem-b4-b4-executable "am"
          (append args (list mid))))
 
+(defun piem-b4-am--check-args (args)
+  (when-let ((badopt (cl-some
+                      (lambda (arg)
+                        (and (string-match
+                              (rx string-start
+                                  (group (or "--outdir" "--mbox-name")) "=")
+                              arg)
+                             (match-string 1 arg)))
+                      args)))
+    (user-error "%s is incompatible with this command" badopt)))
+
 ;;;###autoload
 (defun piem-b4-am-from-mid-create (mid &optional args toggle-worktree)
   "Create a new branch with patches extracted from MID's thread.
@@ -148,15 +159,7 @@ (defun piem-b4-am-from-mid-create (mid &optional args toggle-worktree)
                          (read-string "Message ID: "))
                      (transient-args 'piem-b4-am)
                      current-prefix-arg))
-  (when-let ((badopt (cl-some
-                      (lambda (arg)
-                        (and (string-match
-                              (rx string-start
-                                  (group (or "--outdir" "--mbox-name")) "=")
-                              arg)
-                             (match-string 1 arg)))
-                      args)))
-    (user-error "%s is incompatible with this command" badopt))
+  (piem-b4-am--check-args args)
   (pcase-let* ((coderepo (piem-inbox-coderepo-maybe-read))
                (`(,cover ,mbox-file ,clean-fn)
                 (piem-b4--get-am-files mid coderepo args))
-- 
2.34.0