feat: make lazydev partially work on Neovim < 0.10

lua/lazydev/lsp.lua

@@ -2,6 +2,7 @@ local Workspace = require("lazydev.workspace")
 
 local M = {}
 M.attached = {} ---@type table<number,number>
+M.did_global_handler = false
 
 function M.assert(client)
   assert(client and client.name == "lua_ls", "lazydev: Not a lua_ls client??")
@@ -21,46 +22,60 @@ function M.attach(client)
   -- We need to make sure that each client has its own handlers table.
   client.handlers = vim.tbl_extend("force", {}, client.handlers or {})
 
-  ---@param params lsp.ConfigurationParams
-  client.handlers["workspace/configuration"] = function(err, params, ctx, cfg)
-    local c = vim.lsp.get_client_by_id(ctx.client_id)
-    assert(c == client, "lazydev: Invalid client " .. (c and c.name or "unknown"))
-    M.assert(c)
-    if not params.items or #params.items == 0 then
-      return {}
+  if vim.fn.has("nvim-0.10") == 0 then
+    if M.did_global_handler then
+      return
     end
-
-    -- fallback scope
-    if #(client.workspace_folders or {}) > 0 and not params.items[1].scopeUri then
-      return {}
+    M.did_global_handler = true
+    local orig = vim.lsp.handlers["workspace/configuration"]
+    vim.lsp.handlers["workspace/configuration"] = function(err, params, ctx, cfg)
+      if M.attached[ctx.client_id] then
+        return M.on_workspace_configuration(err, params, ctx, cfg)
+      end
+      return orig(err, params, ctx, cfg)
     end
+  else
+    client.handlers["workspace/configuration"] = M.on_workspace_configuration
+  end
+end
 
-    local response = {}
-    for _, item in ipairs(params.items) do
-      if item.section then
-        local settings = client.settings
-        if item.section == "Lua" then
-          local ws = item.scopeUri and Workspace.get(client, vim.uri_to_fname(item.scopeUri))
-            or Workspace.single(client)
-          if ws:enabled() then
-            settings = ws.settings
-          end
-        end
+---@param params lsp.ConfigurationParams
+function M.on_workspace_configuration(err, params, ctx, cfg)
+  local client = vim.lsp.get_client_by_id(ctx.client_id)
+  M.assert(client)
+  if not client or not params.items or #params.items == 0 then
+    return {}
+  end
 
-        local keys = vim.split(item.section, ".", { plain = true }) --- @type string[]
-        local value = vim.tbl_get(settings or {}, unpack(keys))
-        -- For empty sections with no explicit '' key, return settings as is
-        if value == nil and item.section == "" then
-          value = settings
-        end
-        if value == nil then
-          value = vim.NIL
+  -- fallback scope
+  if #(client.workspace_folders or {}) > 0 and not params.items[1].scopeUri then
+    return {}
+  end
+
+  local response = {}
+  for _, item in ipairs(params.items) do
+    if item.section then
+      local settings = client.settings
+      if item.section == "Lua" then
+        local ws = item.scopeUri and Workspace.get(client, vim.uri_to_fname(item.scopeUri)) or Workspace.single(client)
+        if ws:enabled() then
+          settings = ws.settings
         end
-        table.insert(response, value)
       end
+
+      local keys = vim.split(item.section, ".", { plain = true }) --- @type string[]
+      local value = vim.tbl_get(settings or {}, unpack(keys))
+      -- For empty sections with no explicit '' key, return settings as is
+      if value == nil and item.section == "" then
+        value = settings
+      end
+      if value == nil then
+        value = vim.NIL
+      end
+      table.insert(response, value)
     end
-    return response
   end
+  return response
 end
 
 ---@param client vim.lsp.Client