Define and test stomp errors

stomp.el

@@ -23,6 +23,15 @@
 
 (require 'map)
 
+(define-error 'stomp-error
+  "Error encountered in implementation of the STOMP protocol")
+
+(define-error 'stomp-invalid-header
+  "Invalid STOMP frame header encounterd")
+
+(define-error 'stomp-invalid-frame
+  "Invalid STOMP frame encountered")
+
 (defun stomp-send-frame (process frame)
   "Send a message to a STOMP process"
   (process-send-string process (stomp-frame-to-string frame)))
@@ -84,7 +93,7 @@
     (let ((header (split-string (thing-at-point 'line) ":")))
       (cond
        ((= (line-end-position) end-point) headers)
-       ((> (length header) 2) (throw 'invalid-header nil))
+       ((> (length header) 2) (signal 'stomp-invalid-header (list header)))
        (t (stomp-read-headers
            buffer
            end-point
@@ -125,7 +134,7 @@
    '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"))
+    (signal 'stomp-invalid-frame (list "Expected frame to have a command" frame)))
   (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"

test/test.el

@@ -107,3 +107,20 @@
   (setq frame '((headers . (("okay" . "bye")))))
 
   (should (equal nil (stomp-frame-header "bla" frame))))
+
+(ert-deftest will-signal-invald-frame ()
+  "`stomp-frame-to-string` should signal an invalid frame error
+when attempting to send a frame without a command defined in it"
+  (should-error (stomp-frame-to-string '()) :type 'stomp-invalid-frame))
+
+(ert-deftest will-signal-wrong-type-filter-function ()
+  "`stomp-filter-function` should signal a `wrong-type-argument`
+  error when `callback` is not a callback"
+  (should-error (stomp-filter-function '(not a function) :type 'wrong-type-argument)))
+
+(ert-deftest will-signal-invalid-header ()
+  "`stomp-read-headers` should signal a `stomp-invalid-frame`
+error when a header containing colons is encountered"
+  (with-testing-buffer
+   "invalid_header_frame.txt"
+   (should-error (stomp-read-headers (current-buffer) (point-max)) :type 'stomp-invalid-header)))