Can't make it work with emacs (eglot)

[q3cpma]

Hi, I've read the Emacs recommend config page and the two discussion about emacs in here, but I can't make it work (using harper-ls 0.26 and Emacs 30.1). Here's what I get when enabling eglot with the basic recommended config:

[jsonrpc] D[12:59:41.765] Running language server: harper-ls --stdio
[jsonrpc] e[12:59:41.765] --> initialize[1] {"jsonrpc":"2.0","id":1,"method":"initialize","params":{"processId":18024,"clientInfo":{"name":"Eglot","version":"1.17.30"},"rootPath":"/home/user/Programming/","rootUri":"file:///home/user/Programming","initializationOptions":{},"capabilities":{"workspace":{"applyEdit":true,"executeCommand":{"dynamicRegistration":false},"workspaceEdit":{"documentChanges":true},"didChangeWatchedFiles":{"dynamicRegistration":true},"symbol":{"dynamicRegistration":false},"configuration":true,"workspaceFolders":true},"textDocument":{"synchronization":{"dynamicRegistration":false,"willSave":true,"willSaveWaitUntil":true,"didSave":true},"completion":{"dynamicRegistration":false,"completionItem":{"snippetSupport":true,"deprecatedSupport":true,"resolveSupport":{"properties":["documentation","details","additionalTextEdits"]},"tagSupport":{"valueSet":[1]}},"contextSupport":true},"hover":{"dynamicRegistration":false,"contentFormat":["markdown","plaintext"]},"signatureHelp":{"dynamicRegistration":false,"signatureInformation":{"parameterInformation":{"labelOffsetSupport":true},"documentationFormat":["markdown","plaintext"],"activeParameterSupport":true}},"references":{"dynamicRegistration":false},"definition":{"dynamicRegistration":false,"linkSupport":true},"declaration":{"dynamicRegistration":false,"linkSupport":true},"implementation":{"dynamicRegistration":false,"linkSupport":true},"typeDefinition":{"dynamicRegistration":false,"linkSupport":true},"documentSymbol":{"dynamicRegistration":false,"hierarchicalDocumentSymbolSupport":true,"symbolKind":{"valueSet":[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]}},"documentHighlight":{"dynamicRegistration":false},"codeAction":{"dynamicRegistration":false,"resolveSupport":{"properties":["edit","command"]},"dataSupport":true,"codeActionLiteralSupport":{"codeActionKind":{"valueSet":["quickfix","refactor","refactor.extract","refactor.inline","refactor.rewrite","source","source.organizeImports"]}},"isPreferredSupport":true},"formatting":{"dynamicRegistration":false},"rangeFormatting":{"dynamicRegistration":false},"rename":{"dynamicRegistration":false},"inlayHint":{"dynamicRegistration":false},"publishDiagnostics":{"relatedInformation":false,"codeDescriptionSupport":false,"tagSupport":{"valueSet":[1,2]}}},"window":{"showDocument":{"support":true},"workDoneProgress":true},"general":{"positionEncodings":["utf-32","utf-8","utf-16"]},"experimental":{}},"workspaceFolders":[{"uri":"file:///home/user/Programming","name":"~/Programming/"}]}}
[jsonrpc] e[12:59:41.767] <-- initialize[1] {"jsonrpc":"2.0","result":{"capabilities":{"codeActionProvider":true,"executeCommandProvider":{"commands":["HarperAddToUserDict","HarperAddToFileDict","HarperOpen","HarperIgnoreLint"]},"textDocumentSync":{"change":1,"openClose":true,"save":true}}},"id":1}
[jsonrpc] e[12:59:41.767] --> initialized {"jsonrpc":"2.0","method":"initialized","params":{}}
[jsonrpc] e[12:59:41.767] --> textDocument/didOpen {"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{"uri":"file:///home/user/Programming/zero_copy.txt","version":0,"languageId":"english-prose","text":"..."}}}
[jsonrpc] e[12:59:41.768] --> workspace/didChangeConfiguration {"jsonrpc":"2.0","method":"workspace/didChangeConfiguration","params":{"settings":{}}}
[stderr]  2025-03-22T11:59:41.768101Z ERROR harper_ls::backend: Settings must contain a "harper-ls" key.
[jsonrpc] e[12:59:41.770] <-- window/logMessage {"jsonrpc":"2.0","method":"window/logMessage","params":{"message":"Server initialized!","type":3}}
[jsonrpc] e[12:59:41.770] <-- workspace/configuration[0] {"jsonrpc":"2.0","method":"workspace/configuration","params":{"items":[{}]},"id":0}
[jsonrpc] e[12:59:41.770] --> workspace/configuration[0] {"jsonrpc":"2.0","id":0,"result":[null]}
[jsonrpc] e[12:59:41.770] <-- workspace/configuration[1] {"jsonrpc":"2.0","method":"workspace/configuration","params":{"items":[{}]},"id":1}
[jsonrpc] e[12:59:41.770] --> workspace/configuration[1] {"jsonrpc":"2.0","id":1,"result":[null]}
[stderr]  2025-03-22T11:59:41.770424Z ERROR harper_ls::backend: Settings must be an object.
[stderr]  2025-03-22T11:59:41.770484Z ERROR harper_ls::backend: Settings must be an object.
[jsonrpc] e[12:59:41.770] <-- client/registerCapability[2] {"jsonrpc":"2.0","method":"client/registerCapability","params":{"registrations":[{"id":"workspace/didChangeWatchedFiles","method":"workspace/didChangeWatchedFiles","registerOptions":{"watchers":[{"globPattern":"**/*","kind":4}]}}]},"id":2}
[jsonrpc] e[12:59:42.984] --> client/registerCapability[2] {"jsonrpc":"2.0","id":2,"result":null}
[jsonrpc] e[12:59:42.985] <-- textDocument/publishDiagnostics {"jsonrpc":"2.0","method":"textDocument/publishDiagnostics","params":{"diagnostics":[],"uri":"file:///home/user/Programming/zero_copy.txt"}}

Seems like it expects some settings of some sort, so I tried using an empty one via (setq-default eglot-workspace-configuration '(:harper-ls nil))), to no avail; the error didn't change despite the required "harper-ls" key now present:

[jsonrpc] e[13:06:51.679] --> workspace/didChangeConfiguration {"jsonrpc":"2.0","method":"workspace/didChangeConfiguration","params":{"settings":{"harper-ls":null}}}
[stderr]  2025-03-22T12:06:51.679423Z ERROR harper_ls::backend: Settings must contain a "harper-ls" key.

Any help appreciated.

[mcecode]

Hi, I take it that the issue is that you're not getting diagnostics for /home/user/Programming/zero_copy.txt? I think the issue is that you're using an unsupported language ID for it, english-prose. You check the language IDs supported by harper-ls in the documentation, since you were trying to edit a .txt file, changing the language ID used to plaintext should make it work.

For the most part, you can ignore the errors about your config, harper-ls will just use the default config if you don't provide it with one. But, I think changing the harper-ls key value from nil to eglot-{} should suppress the errors.

[q3cpma]

Thanks! That was indeed the problem, I didn't know that eglot deduced the languageId from the mode's name...

Shouldn't an unknown languageId raise an error on stderr, though?

[mcecode]

Thanks! That was indeed the problem, I didn't know that eglot deduced the languageId from the mode's name...

Glad it's working for you now. Also, that's interesting behavior, I'll try adding it to our docs as a possible gotcha when using Emacs with harper-ls.

Shouldn't an unknown languageId raise an error on stderr, though?

Maybe changing the behavior of harper-ls to show errors, or at least warnings, when passed a file with an unknown language ID would be better to catch cases like this easier. Will make an issue for it, thanks for the feedback!

[elijah-potter]

Shouldn't an unknown languageId raise an error on stderr, though?

We used to, but some text editors (as part of normal operation) would open Harper on unsupported filetypes. In the end the clogged log files weren't worth it. I'm sure there's a more nuanced solution we haven't tackled yet, though.

[AyakoGFX]

Question

How did you change languageID for english-prose to plaintext?
Can you share your config?

[q3cpma]

On Thu Mar 27, 2025 at 3:28 PM CET, Ayako wrote: ### Question How did you change `languageID` for `english-prose` to `plaintext`? Can you share your config?

Sadly, I ended up not using harper because I didn't realise it was just a spellchecker with a few hardcoded rules instead of a more systematic grammar checker (mainly wanting tenses and conjugation). Still, I just followed https://www.gnu.org/software/emacs/manual/html_node/eglot/Setting-Up-LSP-Servers.html and used '((english-prose-mode :language-id "plaintext") . ("harper-ls" "--stdio")) in the eglot server list.