add harper-ls as a client

[wickedjargon]

harper-ls is a language server that acts as a grammarly alternative:
https://github.com/Automattic/harper

configurable in emacs via eglot:
https://writewithharper.com/docs/integrations/emacs

A vim user demonstrates it here:
https://youtu.be/3p2n2-eiuZw?si=9z_cpvI4xP53_Xzs

[jcs090218]

It shouldn't be too hard to integrate this to lsp-mode. 🤔

[ju6ge]

Actually I am biting my nails of trying to get harper-ls to work 😆

I have created a little package to integrate harper-ls into my doomemacs configuration: https://github.com/ju6ge/lsp-harper.el

But it does not work, harper is started correctly but i get an error from emacs telling me:

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  split-string(nil "\\.")
  #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_293>(#<hash-table equal 0/0 0x134675a07cfd ...>)
  -map(#<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_293> [#<hash-table equal 0/0 0x134675a07cfd ...>])
  lsp--build-workspace-configuration-response(#<hash-table equal 1/1 0x134675a07c93 (("items" . [#<hash-table equal 0/0 0x134675a07cfd nil>]))>)
  lsp--on-request(#s(lsp--workspace :ewoc #s(ewoc :buffer #<buffer *lsp-log: lsp-harper:128984*> :pretty-printer lsp--log-entry-pp :header [[[[... #5 ... #<marker at 8678 in *lsp-log: lsp-harper:128984*>] #4 "" #<marker at 8803 in *lsp-log: lsp-harper:128984*>] #3 DL-LIST #<marker at 8803 in *lsp-log: lsp-harper:128984*>] [#3 [#4 [#5 ... ... #<marker at 6836 in *lsp-log: lsp-harper:128984*>] #s(lsp--log-entry :timestamp "06:35:12 " :process-time 1393 :type incoming-resp :method "initialize" :id 3 :body #<hash-table equal 1/1 0x1346764daa6f ...>) #<marker at 6397 in *lsp-log: lsp-harper:128984*>] #s(lsp--log-entry :timestamp "06:35:11 " :process-time nil :type outgoing-req :method "initialize" :id 3 :body (:processId 128853 :rootPath "/tmp/test-harper" :clientInfo ... :rootUri "file:///tmp/test-harper" :capabilities ... :initializationOptions ... :workDoneToken "1")) #<marker at 1 in *lsp-log: lsp-harper:128984*>] "" #<marker at 1 in *lsp-log: lsp-harper:128984*>] :footer [[[[... #5 ... #<marker at 8018 in *lsp-log: lsp-harper:128984*>] #4 #s(lsp--log-entry :timestamp "06:35:13 " :process-time nil :type outgoing-req :method "textDocument/codeAction" :id 21 :body ...) #<marker at 8348 in *lsp-log: lsp-harper:128984*>] #3 #s(lsp--log-entry :timestamp "06:35:13 " :process-time nil :type incoming-notif :method "window/logMessage" :id nil :body #<hash-table equal 2/2 0x134675a07e82 ...>) #<marker at 8678 in *lsp-log: lsp-harper:128984*>] [#3 [#4 [#5 ... ... #<marker at 1 in *lsp-log: lsp-harper:128984*>] "" #<marker at 1 in *lsp-log: lsp-harper:128984*>] DL-LIST #<marker at 8803 in *lsp-log: lsp-harper:128984*>] "" #<marker at 8803 in *lsp-log: lsp-harper:128984*>] :dll [[[[... #5 ... #<marker at 8348 in *lsp-log: lsp-harper:128984*>] #4 #s(lsp--log-entry :timestamp "06:35:13 " :process-time nil :type incoming-notif :method "window/logMessage" :id nil :body #<hash-table equal 2/2 0x134675a07e82 ...>) #<marker at 8678 in *lsp-log: lsp-harper:128984*>] #3 "" #<marker at 8803 in *lsp-log: lsp-harper:128984*>] [#3 [#4 [#5 ... ... #<marker at 6397 in *lsp-log: lsp-harper:128984*>] #s(lsp--log-entry :timestamp "06:35:11 " :process-time nil :type outgoing-req :method "initialize" :id 3 :body ...) #<marker at 1 in *lsp-log: lsp-harper:128984*>] "" #<marker at 1 in *lsp-log: lsp-harper:128984*>] DL-LIST #<marker at 8803 in *lsp-log: lsp-harper:128984*>] :last-node nil :hf-pp insert) :server-capabilities #<hash-table equal 3/3 0x1346764daa76 ...> :registered-server-capabilities nil :root "/tmp/test-harper" :client #s(lsp--client :language-id nil :add-on? t :new-connection (:connect #f(compiled-function (filter sentinel name environment-fn workspace) #<bytecode -0xf542689bacce9cc>) :test? #f(compiled-function () #<bytecode 0x42470265b3e104>)) :ignore-regexps nil :ignore-messages nil :notification-handlers #<hash-table equal 0/0 0x134676dae084 ...> :request-handlers #<hash-table equal 0/0 0x134676dae6d7 ...> :response-handlers #<hash-table eql 3/6 0x134676dae6b9 ...> :prefix-function nil :uri-handlers #<hash-table equal 0/0 0x134676dae6aa ...> :action-handlers #<hash-table equal 0/0 0x134676dae694 ...> :action-filter nil :major-modes (rust-mode python-mode ess-mode typst-ts-mode markdown-mode) :activation-fn nil :priority -3 :server-id lsp-harper :multi-root nil :initialization-options (:userDictPath "" :fileDictPath "" :linters (:SpellCheck t :SpelledNumbers :json-false :AnA t :SentenceCapitalization t :UnclosedQuotes t :WrongQuotes :json-false :LongSentences t :RepeatedWords t :Spaces t :Matcher t :CorrectNumberSuffix t) :codeActions (:ForceStable :json-false) :markdown (:IgnoreLinkTitle :json-false) :diagnosticSeverity "hint" :isolateEnglish :json-false) :semantic-tokens-faces-overrides nil :custom-capabilities nil :library-folders-fn nil :before-file-open-fn nil :initialized-fn nil :remote? nil :completion-in-comments? nil :path->uri-fn nil :uri->path-fn nil :environment-fn nil :after-open-fn nil :async-request-handlers #<hash-table equal 0/0 0x134676dae581 ...> :download-server-fn nil :download-in-progress? nil :buffers nil :synchronize-sections nil) :host-root nil :proc #<process lsp-harper> :cmd-proc #<process lsp-harper> :buffers (#<buffer main.py>) :semantic-tokens-faces nil :semantic-tokens-modifier-faces nil :extra-client-capabilities nil :status initialized :metadata #<hash-table equal 0/0 0x134677d209fa ...> :watches #<hash-table equal 0/0 0x134677d2099b ...> :workspace-folders nil :last-id 0 :status-string nil :shutdown-action nil :diagnostics #<hash-table equal 0/0 0x134677d2098d ...> :work-done-tokens #<hash-table equal 0/0 0x134677d209b6 ...>) #<hash-table equal 4/4 0x134675a07c80 (("jsonrpc" . "2.0") ("method" . "workspace/configuration") ("params" . #<hash-table equal 1/1 0x134675a07c93 (("items" . [#<hash-table equal 0/0 0x134675a07cfd nil>]))>) ("id" . 0))>)
  lsp--parser-on-message(#<hash-table equal 4/4 0x134675a07c80 ...> #s(lsp--workspace :ewoc #s(ewoc :buffer #<buffer *lsp-log: lsp-harper:128984*> :pretty-printer lsp--log-entry-pp :header [[[[... #6 ... #<marker at 8678 in *lsp-log: lsp-harper:128984*>] #5 "" #<marker at 8803 in *lsp-log: lsp-harper:128984*>] #4 DL-LIST #<marker at 8803 in *lsp-log: lsp-harper:128984*>] [#4 [#5 [#6 ... ... #<marker at 6836 in *lsp-log: lsp-harper:128984*>] #s(lsp--log-entry :timestamp "06:35:12 " :process-time 1393 :type incoming-resp :method "initialize" :id 3 :body #<hash-table equal 1/1 0x1346764daa6f ...>) #<marker at 6397 in *lsp-log: lsp-harper:128984*>] #s(lsp--log-entry :timestamp "06:35:11 " :process-time nil :type outgoing-req :method "initialize" :id 3 :body (:processId 128853 :rootPath "/tmp/test-harper" :clientInfo ... :rootUri "file:///tmp/test-harper" :capabilities ... :initializationOptions ... :workDoneToken "1")) #<marker at 1 in *lsp-log: lsp-harper:128984*>] "" #<marker at 1 in *lsp-log: lsp-harper:128984*>] :footer [[[[... #6 ... #<marker at 8018 in *lsp-log: lsp-harper:128984*>] #5 #s(lsp--log-entry :timestamp "06:35:13 " :process-time nil :type outgoing-req :method "textDocument/codeAction" :id 21 :body ...) #<marker at 8348 in *lsp-log: lsp-harper:128984*>] #4 #s(lsp--log-entry :timestamp "06:35:13 " :process-time nil :type incoming-notif :method "window/logMessage" :id nil :body #<hash-table equal 2/2 0x134675a07e82 ...>) #<marker at 8678 in *lsp-log: lsp-harper:128984*>] [#4 [#5 [#6 ... ... #<marker at 1 in *lsp-log: lsp-harper:128984*>] "" #<marker at 1 in *lsp-log: lsp-harper:128984*>] DL-LIST #<marker at 8803 in *lsp-log: lsp-harper:128984*>] "" #<marker at 8803 in *lsp-log: lsp-harper:128984*>] :dll [[[[... #6 ... #<marker at 8348 in *lsp-log: lsp-harper:128984*>] #5 #s(lsp--log-entry :timestamp "06:35:13 " :process-time nil :type incoming-notif :method "window/logMessage" :id nil :body #<hash-table equal 2/2 0x134675a07e82 ...>) #<marker at 8678 in *lsp-log: lsp-harper:128984*>] #4 "" #<marker at 8803 in *lsp-log: lsp-harper:128984*>] [#4 [#5 [#6 ... ... #<marker at 6397 in *lsp-log: lsp-harper:128984*>] #s(lsp--log-entry :timestamp "06:35:11 " :process-time nil :type outgoing-req :method "initialize" :id 3 :body ...) #<marker at 1 in *lsp-log: lsp-harper:128984*>] "" #<marker at 1 in *lsp-log: lsp-harper:128984*>] DL-LIST #<marker at 8803 in *lsp-log: lsp-harper:128984*>] :last-node nil :hf-pp insert) :server-capabilities #<hash-table equal 3/3 0x1346764daa76 ...> :registered-server-capabilities nil :root "/tmp/test-harper" :client #s(lsp--client :language-id nil :add-on? t :new-connection (:connect #f(compiled-function (filter sentinel name environment-fn workspace) #<bytecode -0xf542689bacce9cc>) :test? #f(compiled-function () #<bytecode 0x42470265b3e104>)) :ignore-regexps nil :ignore-messages nil :notification-handlers #<hash-table equal 0/0 0x134676dae084 ...> :request-handlers #<hash-table equal 0/0 0x134676dae6d7 ...> :response-handlers #<hash-table eql 3/6 0x134676dae6b9 ...> :prefix-function nil :uri-handlers #<hash-table equal 0/0 0x134676dae6aa ...> :action-handlers #<hash-table equal 0/0 0x134676dae694 ...> :action-filter nil :major-modes (rust-mode python-mode ess-mode typst-ts-mode markdown-mode) :activation-fn nil :priority -3 :server-id lsp-harper :multi-root nil :initialization-options (:userDictPath "" :fileDictPath "" :linters (:SpellCheck t :SpelledNumbers :json-false :AnA t :SentenceCapitalization t :UnclosedQuotes t :WrongQuotes :json-false :LongSentences t :RepeatedWords t :Spaces t :Matcher t :CorrectNumberSuffix t) :codeActions (:ForceStable :json-false) :markdown (:IgnoreLinkTitle :json-false) :diagnosticSeverity "hint" :isolateEnglish :json-false) :semantic-tokens-faces-overrides nil :custom-capabilities nil :library-folders-fn nil :before-file-open-fn nil :initialized-fn nil :remote? nil :completion-in-comments? nil :path->uri-fn nil :uri->path-fn nil :environment-fn nil :after-open-fn nil :async-request-handlers #<hash-table equal 0/0 0x134676dae581 ...> :download-server-fn nil :download-in-progress? nil :buffers nil :synchronize-sections nil) :host-root nil :proc #<process lsp-harper> :cmd-proc #<process lsp-harper> :buffers (#<buffer main.py>) :semantic-tokens-faces nil :semantic-tokens-modifier-faces nil :extra-client-capabilities nil :status initialized :metadata #<hash-table equal 0/0 0x134677d209fa ...> :watches #<hash-table equal 0/0 0x134677d2099b ...> :workspace-folders nil :last-id 0 :status-string nil :shutdown-action nil :diagnostics #<hash-table equal 0/0 0x134677d2098d ...> :work-done-tokens #<hash-table equal 0/0 0x134677d209b6 ...>))
  #f(compiled-function (msg) #<bytecode 0xd918a3c091cda38>)(#<hash-table equal 4/4 0x134675a07c80 ...>)
  mapc(#f(compiled-function (msg) #<bytecode 0xd918a3c091cda38>) (#<hash-table equal 3/3 0x134675a07d8c ...> #<hash-table equal 4/4 0x134675a07c80 ...> #<hash-table equal 4/4 0x134675a436eb ...> #<hash-table equal 3/3 0x1346759ab10a ...> #<hash-table equal 3/3 0x134675bd8e74 ...> #<hash-table equal 3/3 0x134675bd8f1e ...> #<hash-table equal 3/3 0x134675bd884b ...>))
  #f(compiled-function (proc input) #<bytecode -0xba3790204faec14>)(#<process lsp-harper> "Content-Length: 98\15\n\15\n{\"jsonrpc\":\"2.0\",\"method\":\"window/logMessage\",\"params\":{\"message\":\"Server initialized!\",\"type\":3}}Content-Length: 83\15\n\15\n{\"jsonrpc\":\"2.0\",\"method\":\"workspace/configuration\",\"params\":{\"items\":[{}]},\"id\":0}Content-Length: 83\15\n\15\n{\"jsonrpc\":\"2.0\",\"method\":\"workspace/configuration\",\"params\":{\"items\":[{}]},\"id\":1}Content-Length: 37\15\n\15\n{\"jsonrpc\":\"2.0\",\"result\":[],\"id\":16}Content-Length: 37\15\n\15\n{\"jsonrpc\":\"2.0\",\"result\":[],\"id\":17}Content-Length: 37\15\n\15\n{\"jsonrpc\":\"2.0\",\"result\":[],\"id\":19}Content-Length: 37\15\n\15\n{\"jsonrpc\":\"2.0\",\"result\":[],\"id\":21}")

Unraveling that leads me to the following conclusion:

1. Harper is sending the following workspace/configuration request

{
  "jsonrpc": "2.0",
  "method": "workspace/configuration",
  "params": {"items": [{}]},
  "id": 0
}

2. lsp-mode is choking on trying to parse that, because items is basically an empty list. This makes no sense, because according to the documentation for this request, the purpose is to query editor configuration. But since items is empty this request is send requesting nothing … Being very pedantic the Schema for items does allow empty objects, but there is no sensible reason for this to be empty.

So the question here is, is this a bug with lsp-mode? Or with harper.

Looking at the harper source code, this is more an issue with the underlying lsp server library tower-lsp, because harper is not (as far as I can tell) explicity doing anything with this request. Given that tower-lsp is currently in maintainership limbo I don't think this will get fixed soon. And the community fork has not gained traction as far as I can tell.

I actually came here to open issue regarding graceful handling of empty workspace/configuration requests, but given there was an explicit request for harper I thought this would be a good place to put the full context. Should this be it's own issue?

Kind regards,
ju6ge

[jcs090218]

Sounds reasonable to me. 🤔 I would recommend still opening an issue to the upstream, but fixing it here is probably easier. Feel free to open a PR for this.

[itamarst]

Apparently Harper switched to a maintained fork of tower-lsp, so filing the bug upstream with them seems like it might get it fixed: https://github.com/tower-lsp-community/tower-lsp-server

[ju6ge]

In the meantime I did do some more digging but have hit a wall trying to implement a workaround. To me it seems that lsp-mode has quite a hard requirement to get a key to load the configuration of the lsp-server.

I did learn more about the purpose of the workstation/configuration it is supposed to be a better mechanism enabling hot reloading of configuration changes without restarting the lsp-server but information for how it should be used is very under specified, which makes it quite hard to define some sane default assumptions that will work across lsp server implementations.

So harper actually uses it to load its configuration as apposed to excepting the configuration via the intialization options. So maybe there is a way to solve this on the harper side of things. I did get emacs to not hit an exception when using harper, but I did it by basically ignoring the request and just returning an empty response. But then harper quit complaining that it could not find the harper-ls key in the configuartion. This seems just backwards, harper is requesting all configuration and then looking for its specific key instead of sending harper-ls as section in the configuration request. So I am not sure that my initial conclusion that this needs to be addressed on tower-lsp side is actually completly correct …