Add stomp-frame-to-string

stomp.el

@@ -3,16 +3,10 @@
 
 (require 'map)
 
-(defun stomp-connect (host port)
-  "Connect to a server supporting the STOMP protocol"
-  (message "Not implemented yet"))
-
 ;; TODO: make this send more than just the command
 (defun stomp-send-frame (process frame)
   "Send a message to a STOMP process"
-  (process-send-string
-   process
-   (format "%s\n\n\u0000\n" (alist-get 'command frame))))
+  (process-send-string process (stomp-frame-to-string frame)))
                        
 (defun stomp-filter-function (callback)
   "Filter function to be used with processes"
@@ -86,3 +80,18 @@
     (condition-case nil
         (progn (search-forward-regexp "^$") (line-end-position))
       (error nil))))
+
+(defun stomp-frame-to-string (frame)
+  "Convert a lisp datastructure describing a STOMP frame into a
+   string that could be sent to a server or client. The
+   datastructure should be an alist and should at least have a
+   'command key. Other optional keys are 'headers (another alist)
+   and 'content"
+  (unless (assq 'command frame)
+    (throw 'invalid-frame "A STOMP frame must define a command"))
+  (let ((headers (if (assq 'headers frame) (alist-get 'headers frame) '()))
+        (content (if (assq 'content frame) (alist-get 'content frame) "")))
+    (format "%s\n%s\n%s\u0000"
+            (alist-get 'command frame)
+            (mapconcat (lambda (h) (format "%s:%s\n" (car h) (cdr h))) headers "")
+            content)))

test.el

@@ -57,3 +57,12 @@
     (stomp-delete-frame buffer)
     (with-current-buffer buffer
     (should (equal (buffer-string) "BLA\nsome-header:value\nok:bye\n\ncontent\n\u0000\n")))))
+
+(ert-deftest can-compose-frame ()
+  "Can compose a valid STOMP frame from a LISP datastructure"
+  (let ((frame '()) (headers '()))
+    (map-put frame 'command "SEND")
+    (map-put headers "header" "value")
+    (map-put frame 'headers headers)
+    (map-put frame 'content "Some content")
+    (should (equal (stomp-frame-to-string frame) "SEND\nheader:value\n\nSome content\u0000"))))