Custom project root for all files in a project

[witek]

lsp--calculate-root calculates the project root by asking the user via lsp--find-root-interactively. Here I am missing an option to provide a custom project root for all files in the current project.

My simplified problem / use case:

• First Clojure git project /p/mylib
• Second Clojure git project /p/myapp

By default, Emacs starts a lsp-server / lsp session for each of these projects. This causes that lsp-find-references in /p/mylib does not find the references in /p/myapp. I would prefer the default behavior from VSCode. When adding two "folders" to a VSCode-workspace, there is a single lsp-server which serves both. And all lsp commands work across both folders.

Since Emacs has projects instead of VSCode-workspaces and folders, this is tricky. I still want commands like projectile-find-file or magit-status to work on the individual projects. But I want lsp commands like lsp-find-references to work accross multiple projects.

I discovered that I can get this behavior by providing always the same value /p/all-clj as project root to the interactive question from lsp--find-root-interactively. But this question pops up on every file I open. There is no option to persist my custom root directory.

Proposals:

• Provide a new option in lsp--find-root-interactively so that the user can provide a custom project root which is saved as the value for all files in the current project.
• Extend the (or ...) form in lsp--calculate-root so that a variable is used as the return value. So that the user can set this variable in his configuration or in his .dir-locals.el.

[yyoncho]

I discovered that I can get this behavior by providing always the same value /p/dummy-workspace as project root to the interactive question from lsp--find-root-interactively. But this question pops up on every file I open. There is no option to persist my custom root directory.

lsp-mode persists the roots in lsp-session-file and you should not be asked again.

[witek]

This is the content of my lsp-session-file:

#s(lsp-session ("/p/all-clj") nil #s(hash-table size 65 test equal rehash-size 1.5 rehash-threshold 0.8125 data ()) #s(hash-table size 65 test equal rehash-size 1.5 rehash-threshold 0.8125 data ()) #s(hash-table size 65 test equal rehash-size 1.5 rehash-threshold 0.8125 data ()))

I am very new to Emacs / elisp and I do not understend what this content means. But it seams impossible that this saves the association of all files I have associated to a given lsp-session. It seams it saved the lsp-session /p/all-clj. But it did not save that I have connected /p/mylib/src/mylib/core.clj and /p/myapp/src/myapp/main.clj with this session. And I would like lsp-mode to auto-connect all files from /p/mylib and /p/myapp with this lsp-session.

[yyoncho]

We use the nearest project root if it is already added. If you want to associate files outside of project root with a particular workspace, then there is :library-folders-fn when registering the client which typically is used for /usr/lib like stuff.

[witek]

This is exactly the case. My projects /p/mylib and /p/myapp do not have a common project directory, but I want them to have the same lsp-session /p/all-clj.

How can I leverage :library-folders-fn to customize the lsp-session for my projects?

[yyoncho]

@witek we should add setting like we do here: https://github.com/yyoncho/lsp-mode/blob/master/clients/lsp-pylsp.el#L426

[witek]

we should add setting like we do here: https://github.com/yyoncho/lsp-mode/blob/master/clients/lsp-pylsp.el#L426

But is this really specific to the language specific code? I can imagine having the same issue regardless of the language.

[yyoncho]

the setting can be exposed for all servers. The different servers might have different logic regarding the outside of root files.