feat: priority ranking for LSP clients (#222)

README.md

@@ -461,6 +461,13 @@ require("aerial").setup({
     -- How long to wait (in ms) after a buffer change before updating
     -- Only used when diagnostics_trigger_update = false
     update_delay = 300,
+
+    -- Map of LSP client name to priority. Default value is 10.
+    -- Clients with higher (larger) priority will be used before those with lower priority.
+    -- Set to -1 to never use the client.
+    priority = {
+      -- pyright = 10,
+    },
   },
 
   treesitter = {

doc/aerial.txt

@@ -299,6 +299,13 @@ OPTIONS                                                           *aerial-option
         -- How long to wait (in ms) after a buffer change before updating
         -- Only used when diagnostics_trigger_update = false
         update_delay = 300,
+
+        -- Map of LSP client name to priority. Default value is 10.
+        -- Clients with higher (larger) priority will be used before those with lower priority.
+        -- Set to -1 to never use the client.
+        priority = {
+          -- pyright = 10,
+        },
       },
 
       treesitter = {

lua/aerial/backends/init.lua

@@ -3,8 +3,8 @@ local M = {}
 
 ---@class aerial.Backend
 ---@field is_supported fun(bufnr: integer): boolean, string?
----@field fetch_symbols_sync fun(bufnr: integer, timeout?: integer)
----@field fetch_symbols fun(bufnr: integer)
+---@field fetch_symbols_sync fun(bufnr?: integer, opts?: {timeout?: integer})
+---@field fetch_symbols fun(bufnr?: integer)
 ---@field attach fun(bufnr: integer)
 ---@field detach fun(bufnr: integer)
 
@@ -146,7 +146,7 @@ end
 
 ---@param bufnr? integer
 ---@param items aerial.Symbol[]
----@param context {backend_name: string, lang: string}
+---@param ctx {backend_name: string, lang: string}
 M.set_symbols = function(bufnr, items, ctx)
   if not bufnr or bufnr == 0 then
     bufnr = vim.api.nvim_get_current_buf()
@@ -164,10 +164,11 @@ M.set_symbols = function(bufnr, items, ctx)
   if config.post_add_all_symbols then
     items = config.post_add_all_symbols(bufnr, items, ctx)
     if items == nil then
-      vim.notify_once(
+      vim.notify(
         "aerial.config.post_add_all_symbols should return the symbols to display, but you returned nil or didn't return anything.",
         vim.log.levels.WARN
       )
+      return
     end
   end
 

lua/aerial/backends/lsp/callbacks.lua

@@ -1,6 +1,7 @@
 local backends = require("aerial.backends")
 local config = require("aerial.config")
 local data = require("aerial.data")
+local lsp_util = require("aerial.backends.lsp.util")
 
 local M = {}
 
@@ -191,7 +192,7 @@ M.on_publish_diagnostics = function(_err, result, ctx, _config)
     not bufnr
     or not backends.is_backend_attached(bufnr, "lsp")
     or not config.lsp.diagnostics_trigger_update
-    or not client.server_capabilities.documentSymbolProvider
+    or not lsp_util.client_supports_symbols(client)
   then
     return
   end

lua/aerial/backends/lsp/init.lua

@@ -1,7 +1,9 @@
 local backends = require("aerial.backends")
 local callbacks = require("aerial.backends.lsp.callbacks")
 local config = require("aerial.config")
+local lsp_util = require("aerial.backends.lsp.util")
 local util = require("aerial.backends.util")
+
 local M = {}
 
 local function replace_handler(name, callback, preserve_callback)
@@ -30,25 +32,79 @@ local function hook_handlers(preserve_symbol_callback)
   replace_handler("textDocument/publishDiagnostics", callbacks.on_publish_diagnostics, true)
 end
 
+---@param bufnr integer
+---@return nil|table
+local function get_client(bufnr)
+  local ret
+  local last_priority = -1
+  for _, client in ipairs(vim.lsp.get_active_clients({ bufnr = bufnr })) do
+    local priority = config.lsp.priority[client.name] or 10
+    if lsp_util.client_supports_symbols(client) and priority > last_priority then
+      ret = client
+      last_priority = priority
+    end
+  end
+  return ret
+end
+
 M.fetch_symbols = function(bufnr)
-  bufnr = bufnr or 0
+  if not bufnr or bufnr == 0 then
+    bufnr = vim.api.nvim_get_current_buf()
+  end
   local params = { textDocument = vim.lsp.util.make_text_document_params(bufnr) }
-  vim.lsp.buf_request(bufnr, "textDocument/documentSymbol", params, callbacks.symbol_callback)
+  local client = get_client(bufnr)
+  if not client then
+    vim.notify("No LSP client found that supports symbols", vim.log.levels.WARN)
+    return
+  end
+  local request_success =
+    client.request("textDocument/documentSymbol", params, callbacks.symbol_callback, bufnr)
+  if not request_success then
+    vim.notify("Error requesting document symbols", vim.log.levels.WARN)
+  end
 end
 
 M.fetch_symbols_sync = function(bufnr, opts)
-  bufnr = bufnr or 0
+  if not bufnr or bufnr == 0 then
+    bufnr = vim.api.nvim_get_current_buf()
+  end
   opts = vim.tbl_extend("keep", opts or {}, {
     timeout = 4000,
   })
   local params = { textDocument = vim.lsp.util.make_text_document_params(bufnr) }
-  local response_map, err =
-    vim.lsp.buf_request_sync(bufnr, "textDocument/documentSymbol", params, opts.timeout)
-  if err or vim.tbl_isempty(response_map) then
-    vim.notify(string.format("Error fetching document symbols: %s", err), vim.log.levels.ERROR)
+  local client = get_client(bufnr)
+  if not client then
+    vim.notify("No LSP client found that supports symbols", vim.log.levels.WARN)
+    return
+  end
+  local response
+  local request_success = client.request(
+    "textDocument/documentSymbol",
+    params,
+    function(err, result)
+      response = { err = err, result = result }
+    end,
+    bufnr
+  )
+  if not request_success then
+    vim.notify("Error requesting document symbols", vim.log.levels.WARN)
+  end
+
+  local wait_result = vim.wait(opts.timeout, function()
+    return response ~= nil
+  end, 10)
+
+  if wait_result then
+    if response.err then
+      vim.notify(
+        string.format("Error requesting document symbols: %s", response.err),
+        vim.log.levels.WARN
+      )
+    else
+      callbacks.handle_symbols(response.result, bufnr)
+    end
   else
-    local _, response = next(response_map)
-    callbacks.handle_symbols(response.result, bufnr)
+    vim.notify("Timeout when requesting document symbols", vim.log.levels.WARN)
   end
 end
 
@@ -57,7 +113,7 @@ end
 ---@return boolean
 local function is_lsp_attached(bufnr, exclude_id)
   for _, client in pairs(vim.lsp.get_active_clients({ bufnr = bufnr })) do
-    if client.id ~= exclude_id and client.server_capabilities.documentSymbolProvider then
+    if client.id ~= exclude_id and lsp_util.client_supports_symbols(client) then
       return true
     end
   end
@@ -82,7 +138,7 @@ M.on_attach = function(client, bufnr, opts)
     bufnr = 0
   end
   opts = opts or {}
-  if client.server_capabilities.documentSymbolProvider then
+  if lsp_util.client_supports_symbols(client) then
     hook_handlers(opts.preserve_callback)
     -- This is called from the LspAttach autocmd
     -- The client isn't fully attached until just after that autocmd completes, so we need to

lua/aerial/backends/lsp/util.lua

@@ -0,0 +1,12 @@
+local config = require("aerial.config")
+
+local M = {}
+
+---@param client table
+---@return boolean
+M.client_supports_symbols = function(client)
+  return client.server_capabilities.documentSymbolProvider
+    and config.lsp.priority[client.name] ~= -1
+end
+
+return M

lua/aerial/config.lua

@@ -285,6 +285,13 @@ local default_options = {
     -- How long to wait (in ms) after a buffer change before updating
     -- Only used when diagnostics_trigger_update = false
     update_delay = 300,
+
+    -- Map of LSP client name to priority. Default value is 10.
+    -- Clients with higher (larger) priority will be used before those with lower priority.
+    -- Set to -1 to never use the client.
+    priority = {
+      -- pyright = 10,
+    },
   },
 
   treesitter = {