feat: add SSE connection state and reconnection logic

noise-sse.el

@@ -11,6 +11,30 @@
 (require 'json)
 (require 'cl-lib)
 
+(defvar noise-sse--process nil
+  "Active SSE network process, or nil.")
+
+(defvar noise-sse--reconnect-timer nil
+  "Timer for reconnection attempts, or nil.")
+
+(defvar noise-sse--reconnect-delay 1
+  "Current delay in seconds before next reconnection attempt.")
+
+(defcustom noise-sse-max-reconnect-delay 60
+  "Maximum delay in seconds between reconnection attempts."
+  :type 'integer
+  :group 'noise)
+
+(defun noise-sse--increase-reconnect-delay ()
+  "Increase reconnect delay with exponential backoff, capped at max."
+  (setq noise-sse--reconnect-delay
+        (min (* noise-sse--reconnect-delay 2)
+             noise-sse-max-reconnect-delay)))
+
+(defun noise-sse--reset-reconnect-delay ()
+  "Reset reconnect delay to initial value after successful connection."
+  (setq noise-sse--reconnect-delay 1))
+
 (defun noise-sse--parse-event (event-string)
   "Parse an SSE EVENT-STRING into a hash table.
 Returns nil for empty or invalid events."

test/noise-sse-test.el

@@ -29,5 +29,31 @@
   (let ((event "\n\n"))
     (should (null (noise-sse--parse-event event)))))
 
+(ert-deftest noise-sse--initial-state ()
+  "SSE client starts in disconnected state."
+  (let ((noise-sse--process nil)
+        (noise-sse--reconnect-timer nil)
+        (noise-sse--reconnect-delay 1))
+    (should (null noise-sse--process))
+    (should (null noise-sse--reconnect-timer))
+    (should (= 1 noise-sse--reconnect-delay))))
+
+(ert-deftest noise-sse--reconnect-delay-backoff ()
+  "Reconnect delay doubles on each attempt."
+  (let ((noise-sse--reconnect-delay 1))
+    (noise-sse--increase-reconnect-delay)
+    (should (= 2 noise-sse--reconnect-delay))
+    (noise-sse--increase-reconnect-delay)
+    (should (= 4 noise-sse--reconnect-delay))
+    (noise-sse--increase-reconnect-delay)
+    (should (= 8 noise-sse--reconnect-delay))))
+
+(ert-deftest noise-sse--reconnect-delay-max ()
+  "Reconnect delay caps at max value."
+  (let ((noise-sse--reconnect-delay 32)
+        (noise-sse-max-reconnect-delay 60))
+    (noise-sse--increase-reconnect-delay)
+    (should (= 60 noise-sse--reconnect-delay))))
+
 (provide 'noise-sse-test)
 ;;; noise-sse-test.el ends here