Race issue trying to detect prompt

[tmpfs]

Hi,

I think I have detected a bug with the prompt handling in atat.

I am trying to send AT+HTTPCPOST (docs) to an ESP32 and am getting the response buffer as:

\r\n\r\nOK\r\n\r\n>

The OK is detected which will reply to the command (which is marked with NoResponse) and the reply to the send() call will be dispatched but as the prompt is processed synchronously we see the error before the send() completes - the completion of send() is the log line with "success" here:

3.503936 [INFO ] make POST request (http_test http-test/src/main.rs:161)
3.504852 [DEBUG] Sending command with long payload (50 bytes) (atat src/asynch/client.rs:42)
3.506042 [DEBUG] parse (raw): 2 b"\xfe\x00" (rac_core at/esp32/mod.rs:57)
3.569641 [DEBUG] parse (raw): 4 b"\xfe\x00AT" (rac_core at/esp32/mod.rs:57)
3.570617 [DEBUG] parse (raw): 15 b"\xfe\x00AT+HTTPCPOST=" (rac_core at/esp32/mod.rs:57)
3.572052 [DEBUG] parse (raw): 31 b"\xfe\x00AT+HTTPCPOST=\"http://192.168." (rac_core at/esp32/mod.rs:57)
3.573944 [DEBUG] parse (raw): 2 b"\r\n" (rac_core at/esp32/mod.rs:57)
3.574676 [DEBUG] Received echo or whitespace (50/52): b"\xfe\x00AT+HTTPCPOST=\"http://192.168.1.3:8080/post\",17,0\r\n" (atat atat/src/ingress.rs:228)
3.576141 [DEBUG] parse (raw): 2 b"\r\n" (rac_core at/esp32/mod.rs:57)
3.577850 [DEBUG] parse (raw): 4 b"\r\n\r\n" (rac_core at/esp32/mod.rs:57)
3.578857 [DEBUG] parse (raw): 11 b"\r\n\r\nOK\r\n\r\n>" (rac_core at/esp32/mod.rs:57)
3.579650 [DEBUG] Received OK (8/11) (atat atat/src/ingress.rs:268)
3.580627 [DEBUG] parse (raw): 3 b"\r\n>" (rac_core at/esp32/mod.rs:57)
3.581237 [DEBUG] Received prompt (3/3) (atat atat/src/ingress.rs:239)
3.581604 [ERROR] Received prompt but a response is already pending (atat atat/src/ingress.rs:242)
3.582153 [INFO ] success (http_test http-test/src/main.rs:172)

Perhaps I am doing something wrong or do you think this is genuinely a bug?

[tmpfs]

To follow up I've done some research into how I can get this to work for my use case with the most minimal changes possible. I've found out that if I can disable the default prompt detection then I am able to handle the prompt internally via Urc parsing instead.

Then the next problem is how I can write the POST body bytes after detecting the prompt which currrently isn't possible without providing raw access to the client writer (as the UART is split and Client takes ownership of the writer) so I implemented Deref and DerefMut on Client and it now works for my use case, I can POST data with AT+HTTPCPOST 😁

Would you be interested in a PR that implements Deref/DerefMut on Client and adds a means to disable the default prompt behavior in AtDigester so this kind of AT command flow is doable with atat?