main: Replace `sleep` call with a `wait-group`

The `sleep` call allowed me to test the behaviour of the program, since
without it, it would exit before the WebSocket messages had a chance to
be sent and received.

But we shouldn't be waiting a fixed number of seconds for the program to
execute. Instead, we should only keep the program alive as long as there
are messages to be sent and received.

This adds a Go-style wait group using my wait-group library that
increments the wait group when we send a WebSocket message, and
decrements it when we receive a WebSocket response. That allows us to
keep the program alive only for the amount of time necessary for the
messages to be exchanged.

2 files changed, 15 insertions, 6 deletions

diff --git a/l/extreload.asd b/l/extreload.asd
index 21a5329..8a1cfc2 100644
--- a/l/extreload.asd
+++ b/l/extreload.asd
@@ -1,7 +1,8 @@
 (asdf:defsystem extreload
   :version "0.0.1"
   :depends-on (:jsown
-               :websocket-driver-client)
+                :wait-group
+                :websocket-driver-client)
   :components ((:module "src"
                 :serial t
                 :components ((:file "package")
diff --git a/l/src/main.lisp b/l/src/main.lisp
index 42c0ccd..7ad0611 100644
--- a/l/src/main.lisp
+++ b/l/src/main.lisp
@@ -2,14 +2,16 @@
 
 (defvar *client* (wsd:make-client "ws://127.0.0.1:55755/devtools/browser/ec1d4b1c-ced0-47ab-a32e-6fdd5b51e1ba"))
 
+(defvar *wg* (wait-group:make-wait-group))
+
 (defun main ()
   (wsd:start-connection *client*)
 
   (wsd:on :message *client* #'ws-on-message)
 
-  (wsd:send *client* (target-get-targets-msg 1))
+  (websocket-send *client* (target-get-targets-msg 1))
 
-  (sleep 5)
+  (wait-group:wait *wg*)
 
   (wsd:close-connection *client*))
 
@@ -49,7 +51,9 @@
         (reload-extension
           (json-obj-get
             (json-obj-get response "params")
-            "sessionId")))))
+            "sessionId")))
+
+    (wait-group:done *wg*)))
 
 (defun parse-get-targets-response (response)
   (let* ((result (json-obj-get response "result"))
@@ -78,11 +82,11 @@
 
 (defun attach-to-target (extension)
   (let ((target-id (json-obj-get extension "targetId")))
-    (wsd:send *client*
+    (websocket-send *client*
               (target-attach-to-target-msg 2 target-id))))
 
 (defun reload-extension (session-id)
-  (wsd:send *client*
+  (websocket-send *client*
             (runtime-evaluate-msg 1 session-id "chrome.runtime.reload()")))
 
 (defun extension-targets (targets)
@@ -91,3 +95,7 @@
                       "background_page")))
 
     (filter #'extensionp targets)))
+
+(defun websocket-send (client data)
+  (wsd:send *client* data)
+  (wait-group:add *wg*))