Crash with SyntaxError: Unexpected token C in JSON at position 1644

I saw a case very similar to https://github.com/microsoft/vscode-languageserver-node/issues/436

SyntaxError: Unexpected token C in JSON at position 1644
    at JSON.parse (<anonymous>)
    at StreamMessageReader.onData (node_modules/vscode-jsonrpc/lib/messageReader.js:182:29)
    at Socket.listen.readable.on (node_modules/vscode-jsonrpc/lib/messageReader.js:148:18)
    at Socket.emit (events.js:198:13)
    at addChunk (_stream_readable.js:288:12)
    at readableAddChunk (_stream_readable.js:269:11)
    at Socket.Readable.push (_stream_readable.js:224:10)
    at Pipe.onStreamRead [as onread] (internal/stream_base_commons.js:94:17)

It looks like with certain characters the Emacs lsp-mode LSP client sends a bogus request. I’ve entered an issue with them to improve the situation https://github.com/emacs-lsp/lsp-mode/issues/1246

That issue contains repro steps and shows how to repro the example using a fork of the lsp-sample language server integrated into Emacs.

Could this repo be updated to more gracefully handle what looks to be a bogus request? That would help so that language servers don’t get killed because of an issue in an LSP client.

Please let me know other info/debug output I can provide to help.

[dbaeumer]

The response has a wrong Content-Length set. This is why you end up with the additional “C”. It basically belongs to the header of the next message.

[vscodebot[bot]]

This issue has been closed automatically because it needs more information and has not had recent activity. See also our issue reporting guidelines.

Happy Coding!