fix(lsp): skip invalid file watcher globs #40376 #40396

Some servers register `workspace/didChangeWatchedFiles` watchers for URI
schemes that cannot be watched locally. Skipping the unsupported glob
and keep the rest of the registration batch active.

runtime/lua/vim/lsp/_watchfiles.lua

@@ -1,11 +1,53 @@
 local bit = require('bit')
 local glob = vim.glob
 local watch = vim._watch
+local log = require('vim.lsp.log')
 local protocol = require('vim.lsp.protocol')
 local lpeg = vim.lpeg
 
 local M = {}
 
+-- Use a bounded set to suppress repeat warnings without unbounded growth.
+---@type table<string, true>
+local logged_invalid_patterns = {}
+---@type string[]
+local logged_invalid_pattern_keys = {}
+local logged_invalid_pattern_key_index = 1
+
+---@param key string
+local function remember_invalid_pattern(key)
+  local old_key = logged_invalid_pattern_keys[logged_invalid_pattern_key_index]
+  if old_key then
+    logged_invalid_patterns[old_key] = nil
+  end
+  logged_invalid_patterns[key] = true
+  logged_invalid_pattern_keys[logged_invalid_pattern_key_index] = key
+  logged_invalid_pattern_key_index = logged_invalid_pattern_key_index % 20 + 1
+end
+
+--- Parses a glob pattern and logs invalid patterns once.
+---@param pattern string
+---@param client vim.lsp.Client
+---@return vim.lpeg.Pattern?
+local function glob_to_lpeg(pattern, client)
+  local ok, pattern_or_err = pcall(glob.to_lpeg, pattern)
+  if ok then
+    return pattern_or_err
+  end
+  local key = string.format('%d:%s', client.id, pattern)
+  if not logged_invalid_patterns[key] then
+    log.error(
+      string.format(
+        'LSP[%s] skipping invalid workspace/didChangeWatchedFiles globPattern',
+        client.name
+      ),
+      pattern,
+      pattern_or_err
+    )
+    remember_invalid_pattern(key)
+  end
+end
+
 if vim.fn.has('win32') == 1 or vim.fn.has('mac') == 1 then
   M._watchfunc = watch.watch
 elseif vim.fn.executable('inotifywait') == 1 then
@@ -62,24 +104,22 @@ function M.register(reg, client_id)
     local glob_pattern = w.globPattern
 
     if type(glob_pattern) == 'string' then
-      local pattern = glob.to_lpeg(glob_pattern)
-      if not pattern then
-        error('Cannot parse pattern: ' .. glob_pattern)
-      end
-      for _, folder in ipairs(client.workspace_folders) do
-        local base_dir = vim.uri_to_fname(folder.uri)
-        table.insert(watch_regs[base_dir], { pattern = pattern, kind = kind })
+      local pattern = glob_to_lpeg(glob_pattern, client)
+      if pattern then
+        for _, folder in ipairs(client.workspace_folders) do
+          local base_dir = vim.uri_to_fname(folder.uri)
+          table.insert(watch_regs[base_dir], { pattern = pattern, kind = kind })
+        end
       end
     else
       local base_uri = glob_pattern.baseUri
       local uri = type(base_uri) == 'string' and base_uri or base_uri.uri
       local base_dir = vim.uri_to_fname(uri)
-      local pattern = glob.to_lpeg(glob_pattern.pattern)
-      if not pattern then
-        error('Cannot parse pattern: ' .. glob_pattern.pattern)
+      local pattern = glob_to_lpeg(glob_pattern.pattern, client)
+      if pattern then
+        local relative_pattern = lpeg.P(base_dir .. '/') * pattern --[[@as vim.lpeg.Pattern]]
+        table.insert(watch_regs[base_dir], { pattern = relative_pattern, kind = kind })
       end
-      pattern = lpeg.P(base_dir .. '/') * pattern
-      table.insert(watch_regs[base_dir], { pattern = pattern, kind = kind })
     end
   end
 

test/functional/plugin/lsp_spec.lua

@@ -3730,6 +3730,8 @@ describe('LSP', function()
 
           exec_lua(create_server_definition)
           local result = exec_lua(function()
+            local logfile = vim.lsp.log.get_filename()
+            vim.fn.writefile({ '' }, logfile)
             local server = _G._create_server()
             local client_id = assert(vim.lsp.start({
               name = 'watchfiles-test',
@@ -3770,6 +3772,17 @@ describe('LSP', function()
                   method = 'workspace/didChangeWatchedFiles',
                   registerOptions = {
                     watchers = {
+                      {
+                        globPattern = 'a/**b',
+                        kind = 7,
+                      },
+                      {
+                        globPattern = {
+                          baseUri = vim.uri_from_fname(root_dir),
+                          pattern = '{foo}',
+                        },
+                        kind = 7,
+                      },
                       {
                         globPattern = '**/watch',
                         kind = 7,
@@ -3797,12 +3810,13 @@ describe('LSP', function()
 
             vim.lsp.get_client_by_id(client_id):stop()
 
-            return server.messages
+            return { logfile = logfile, messages = server.messages }
           end)
 
           local uri = vim.uri_from_fname(root_dir .. '/watch')
+          local messages = result.messages
 
-          eq(6, #result)
+          eq(6, #messages)
 
           eq({
             method = 'workspace/didChangeWatchedFiles',
@@ -3814,7 +3828,7 @@ describe('LSP', function()
                 },
               },
             },
-          }, result[3])
+          }, messages[3])
 
           eq({
             method = 'workspace/didChangeWatchedFiles',
@@ -3826,7 +3840,18 @@ describe('LSP', function()
                 },
               },
             },
-          }, result[4])
+          }, messages[4])
+
+          t.assert_log(
+            '%[ERROR%].-skipping invalid workspace/didChangeWatchedFiles globPattern.-'
+              .. pesc('a/**b'),
+            result.logfile
+          )
+          t.assert_log(
+            '%[ERROR%].-skipping invalid workspace/didChangeWatchedFiles globPattern.-'
+              .. pesc('{foo}'),
+            result.logfile
+          )
         end
       )
     end