tower-lsp hangs on exit notification

[mrnossiom]

Many users of tower-lsp have reported issues when sending an exit notification

See original issues ebkalderon/tower-lsp#428, ebkalderon/tower-lsp#399, ebkalderon/tower-lsp#424 (duplicate).
See denoland/deno#20700. Fixed with a timeout workaround on their side.
See Automattic/harper#139.

jfly had already made a PR ebkalderon/tower-lsp#428.

However, I am unsure of the steps taken in his PR. Besides, it changes public API.

Furthermore, after reviewing the relevant part (https://github.com/tower-lsp/tower-lsp/blob/main/src/transport.rs#L134) changing the return to a break should disconnect the channels and stop the join. I couldn't reproduce it with helix tonight. If someone has a minimum repro or steps to see the bug... 😄

EDIT: swapped return and break

[jfly]

However, I am unsure of the steps taken in his PR

@mrnossiom, I've reposted my PR to this fork, let's discuss over there: #14

Besides, it changes public API.

Are you referring to this? Let's discuss over there.

Furthermore, after reviewing the relevant part (https://github.com/tower-lsp/tower-lsp/blob/main/src/transport.rs#L134) changing the break to a return should disconnect the channels and stop the join

You've linked to a line of code that is a return. Did you mean to say "changing the return to a break"?

If someone has a minimum repro or steps to see the bug... 😄

Sure, here's a minimal repro. You'll need to open 2 terminals.

In terminal 1, clone and run harper-ls:

$ [email protected]:elijah-potter/harper.git
$ cd harper
$ cargo run --bin harper-ls
...
Listening on 127.0.0.1:4000

In terminal 2, run something like this:

$ echo 'print(f"do not panic")  # this is the bst' > /tmp/test.py
$ nix run github:jfly/lsp-client.py -- 127.0.0.1:4000 --open /tmp/test.py -vvv

(If you do not have nix installed, you'll have to clone https://github.com/jfly/lsp-client.py and futz with poetry to run this.)

In terminal 1, you will see harper print this, but it does not exit:

2024-11-22T08:55:53.085179Z  INFO tower_lsp::service::layers: shutdown request received, shutting down
2024-11-22T08:55:53.093449Z  INFO tower_lsp::service::layers: exit notification received, stopping

In terminal 2, you will see something like this:

INFO:lsp_client.client:>> {"jsonrpc": "2.0", "id": 1, "method": "initialize", "params": {"capabilities": {"textDocument": {"publishDiagnostics": {"dataSupport": true, "relatedInformation": true}}}}}
INFO:lsp_client.client:<< {"jsonrpc":"2.0","result":{"capabilities":{"codeActionProvider":true,"executeCommandProvider":{"commands":["HarperAddToUserDict","HarperAddToFileDict","HarperOpen"]},"textDocumentSync":{"change":1,"openClose":true,"save":true}}},"id":1}
INFO:lsp_client.client:>> {"jsonrpc": "2.0", "method": "initialized", "params": {}}
INFO:lsp_client.client:>> {"jsonrpc": "2.0", "method": "textDocument/didOpen", "params": {"textDocument": {"languageId": "python", "text": "print(f\"do not panic\")  # this is the bst\n", "uri": "file:///tmp/test.py", "version": 0}}}
INFO:lsp_client.client:<< {"jsonrpc":"2.0","method":"window/logMessage","params":{"message":"Server initialized!","type":3}}
INFO:lsp_client.client:<< {"jsonrpc":"2.0","method":"workspace/configuration","params":{"items":[{}]},"id":0}
INFO:lsp_client.client:>> {"jsonrpc": "2.0", "id": 0, "result": []}
INFO:lsp_client.client:<< {"jsonrpc":"2.0","method":"workspace/configuration","params":{"items":[{}]},"id":1}
INFO:lsp_client.client:>> {"jsonrpc": "2.0", "id": 1, "result": []}
INFO:lsp_client.client:<< {"jsonrpc":"2.0","method":"textDocument/publishDiagnostics","params":{"diagnostics":[{"message":"This sentence does not start with a capital letter","range":{"end":{"character":27,"line":0},"start":{"character":26,"line":0}},"severity":4,"source":"Harper"},{"message":"Did you mean to spell “bst” this way?","range":{"end":{"character":41,"line":0},"start":{"character":38,"line":0}},"severity":4,"source":"Harper"}],"uri":"file:///tmp/test.py"}}
INFO:lsp_client.client:>> {"jsonrpc": "2.0", "id": 2, "method": "shutdown"}
INFO:lsp_client.client:<< {"jsonrpc":"2.0","method":"textDocument/publishDiagnostics","params":{"diagnostics":[],"uri":"file:///tmp/test.py"}}
INFO:lsp_client.client:<< {"jsonrpc":"2.0","result":null,"id":2}
INFO:lsp_client.client:>> {"jsonrpc": "2.0", "method": "exit"}