feat: migrate to vim.lsp.config #3659

Problem:
Nvim 0.11 has vim.lsp.config, which mostly replaces the legacy
nvim-lspconfig "framework".

Solution:
Migrate all configs to `lsp/*` variants. The old configs in
`lua/lspconfig/` are "frozen".

The new configs include these changes:
- `commands` field became raw calls to
  `vim.api.nvim_buf_create_user_command` inside `on_attach`.
- `root_dir` became:
  - `root_markers` whenever the file list was simple didn't need to mach `*`
  - if the logic was complicated, or needed to match something like
    '\*.c', it was defined as a vim.lsp.Config `root_dir` callback.
- `on_config_change` became `before_init`. I don't actually know if this
  is the correct approach, but looking around the documentation of
  `nvim-lspconfig` a saw that it was defined as the function that gets
  called as soon as the config have `root_dir`, and so I thought
  `before_init` might be the closest alternative.
- `docs.description` became a luadoc `@brief` docstring.
- `single_file_support = false`?

Co-authored-by: Aliou Diallo <aliou@users.noreply.github.com>
Co-authored-by: Justin M. Keyes <justinkz@gmail.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/lsp/rescriptls.lua b/lsp/rescriptls.lua
new file mode 100644
index 00000000..46c38753
--- /dev/null
+++ b/lsp/rescriptls.lua
@@ -0,0 +1,45 @@
+---@brief
+---
+---https://github.com/rescript-lang/rescript-vscode/tree/master/server
+--
+-- ReScript Language Server can be installed via npm:
+-- ```sh
+-- npm install -g @rescript/language-server
+-- ```
+--
+-- See [package.json](https://github.com/rescript-lang/rescript-vscode/blob/master/package.json#L139)
+-- for init_options supported.
+--
+-- For example, in order to disable the `inlayHints` option:
+-- ```lua
+-- vim.lsp.config('rescriptls', {
+--   settings = {
+--     rescript = {
+--       settings = {
+--         inlayHints = { enable = false },
+--       },
+--     },
+--   })
+-- }
+-- ```
+return {
+  cmd = { 'rescript-language-server', '--stdio' },
+  filetypes = { 'rescript' },
+  root_markers = { 'bsconfig.json', 'rescript.json', '.git' },
+  settings = {},
+  init_options = {
+    extensionConfiguration = {
+      -- buggy, prompts much too often, superseded by incrementalTypechecking, below
+      askToStartBuild = false,
+
+      allowBuiltInFormatter = true, -- lower latency
+      incrementalTypechecking = { -- removes the need for external build process
+        enabled = true,
+        acrossFiles = true,
+      },
+      cache = { projectConfig = { enabled = true } }, -- speed up latency dramatically
+      codeLens = true,
+      inlayHints = { enable = true },
+    },
+  },
+}