fix: close leaked contexts periodically

lua/treesitter-context.lua

@@ -69,6 +69,14 @@ end
 
 ---@param winid integer
 local update_single_context = throttle_by_id(function(winid)
+  -- Remove leaked contexts firstly.
+  local current_win = api.nvim_get_current_win()
+  if config.multiwindow then
+    require('treesitter-context.render').close_leaked_contexts()
+  else
+    require('treesitter-context.render').close_other_contexts(current_win)
+  end
+
   -- Since the update is performed asynchronously, the window may be closed at this moment.
   -- Therefore, we need to check if it is still valid.
   if not api.nvim_win_is_valid(winid) or vim.fn.getcmdtype() ~= '' then
@@ -77,7 +85,7 @@ local update_single_context = throttle_by_id(function(winid)
 
   local bufnr = api.nvim_win_get_buf(winid)
 
-  if cannot_open(bufnr, winid) or not config.multiwindow and winid ~= api.nvim_get_current_win() then
+  if cannot_open(bufnr, winid) or not config.multiwindow and winid ~= current_win then
     require('treesitter-context.render').close(winid)
     return
   end

lua/treesitter-context/render.lua

@@ -386,6 +386,34 @@ end
 
 local M = {}
 
+-- Contexts may sometimes leak due to reasons like the use of 'noautocmd'.
+-- In these cases, affected windows might remain visible, and even ToggleContext
+-- won't resolve the issue, as contexts are identified using parent windows.
+-- Therefore, it's essential to occasionally perform garbage collection to
+-- clean up these leaked contexts.
+function M.close_leaked_contexts()
+  local all_wins = api.nvim_list_wins()
+
+  for parent_winid, window_context in pairs(window_contexts) do
+    if not vim.tbl_contains(all_wins, parent_winid) then
+      close(window_context.context_winid)
+      close(window_context.gutter_winid)
+      window_contexts[parent_winid] = nil
+    end
+  end
+end
+
+--- @param winid integer The only window for which the context should be displayed.
+function M.close_other_contexts(winid)
+  for parent_winid, window_context in pairs(window_contexts) do
+    if parent_winid ~= winid then
+      close(window_context.context_winid)
+      close(window_context.gutter_winid)
+      window_contexts[parent_winid] = nil
+    end
+  end
+end
+
 --- @param bufnr integer
 --- @param winid integer
 --- @param ctx_ranges Range4[]