Implement shutdown and exit RPCs per LSP specification

[Copilot]

VS Code LSP client was failing with No such method shutdown when stopping the server. The server lacked implementation of the required lifecycle RPCs.

Changes

• Added shutdown request handler: Returns null response, sets shutdown_received flag
• Added exit notification handler: Exits with code 0 after proper shutdown, code 1 otherwise per LSP spec
• Added state tracking: shutdown_received: bool field in ProtoLanguageServer to determine exit behavior

Implementation

pub(super) fn shutdown(&mut self, _params: ()) -> BoxFuture<'static, Result<(), ResponseError>> {
    info!("Received shutdown request");
    self.shutdown_received = true;
    Box::pin(async move { Ok(()) })
}

pub(super) fn exit(&mut self, _params: ()) -> ControlFlow<async_lsp::Result<()>> {
    if self.shutdown_received {
        info!("Received exit notification after shutdown, exiting with code 0");
        std::process::exit(0);
    } else {
        warn!("Received exit notification without shutdown, exiting with code 1");
        std::process::exit(1);
    }
}

The LifecycleLayer middleware handles state transitions; these handlers provide the required lifecycle endpoints and exit code semantics.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• docs.rs
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)
• microsoft.github.io
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Implement shutdown and exit RPCs for clean exit</issue_title>
<issue_description>For a clean exit, Shutdown and Exit notifications are sent by the client. Currently protols does not implement these two rpcs on the server side.

VS Code built-in LSP client is failing with the following error when a stop() command is given:

Error checking for protols updates: _ResponseError: No such method shutdown {code: -32601, data: null, stack: 'Error: No such method shutdown
	at handleResp…Trampoline (node:internal/async_hooks:130:17)', message: 'No such method shutdown'}

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Implement shutdown and exit RPCs for clean exit #101

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.