fix(watchfiles): skip Created events when poll starts (#23139)

runtime/lua/vim/_watch.lua

@@ -88,6 +88,9 @@ local default_poll_interval_ms = 2000
 ---               be invoked recursively)
 ---     - children (table|nil)
 ---               A mapping of directory entry name to its recursive watches
+--      - started (boolean|nil)
+--                Whether or not the watcher has first been initialized. Used
+--                to prevent a flood of Created events on startup.
 local function poll_internal(path, opts, callback, watches)
   path = vim.fs.normalize(path)
   local interval = opts and opts.interval or default_poll_interval_ms
@@ -112,7 +115,9 @@ local function poll_internal(path, opts, callback, watches)
       end)
     )
     assert(not start_err, start_err)
-    callback(path, M.FileChangeType.Created)
+    if watches.started then
+      callback(path, M.FileChangeType.Created)
+    end
   end
 
   watches.cancel = function()
@@ -132,6 +137,7 @@ local function poll_internal(path, opts, callback, watches)
       if not watches.children[name] then
         watches.children[name] = {
           is_dir = ftype == 'directory',
+          started = watches.started,
         }
         poll_internal(filepath_join(path, name), opts, callback, watches.children[name])
       end
@@ -150,6 +156,8 @@ local function poll_internal(path, opts, callback, watches)
     watches.children = newchildren
   end
 
+  watches.started = true
+
   return watches.cancel
 end
 

test/functional/lua/watch_spec.lua

@@ -122,10 +122,6 @@ describe('vim._watch', function()
           table.insert(events, { path = path, change_type = change_type })
         end)
 
-        -- polling generates Created events for the existing entries when it starts.
-        expected_events = expected_events + 1
-        wait_for_events()
-
         vim.wait(100)
 
         local watched_path = root_dir .. '/file'
@@ -158,39 +154,35 @@ describe('vim._watch', function()
         root_dir
       )
 
-      eq(5, #result)
-      eq({
-        change_type = exec_lua([[return vim._watch.FileChangeType.Created]]),
-        path = root_dir,
-      }, result[1])
+      eq(4, #result)
       eq({
         change_type = exec_lua([[return vim._watch.FileChangeType.Created]]),
         path = root_dir .. '/file',
-      }, result[2])
+      }, result[1])
       eq({
         change_type = exec_lua([[return vim._watch.FileChangeType.Changed]]),
         path = root_dir,
-      }, result[3])
+      }, result[2])
       -- The file delete and corresponding directory change events do not happen in any
       -- particular order, so allow either
-      if result[4].path == root_dir then
+      if result[3].path == root_dir then
         eq({
           change_type = exec_lua([[return vim._watch.FileChangeType.Changed]]),
           path = root_dir,
-        }, result[4])
+        }, result[3])
         eq({
           change_type = exec_lua([[return vim._watch.FileChangeType.Deleted]]),
           path = root_dir .. '/file',
-        }, result[5])
+        }, result[4])
       else
         eq({
           change_type = exec_lua([[return vim._watch.FileChangeType.Deleted]]),
           path = root_dir .. '/file',
-        }, result[4])
+        }, result[3])
         eq({
           change_type = exec_lua([[return vim._watch.FileChangeType.Changed]]),
           path = root_dir,
-        }, result[5])
+        }, result[4])
       end
     end)
   end)