fix(chat): unwatch buffers when they're unlisted (#1809)

Davidyz · web-flow · commit ea29e112916b · 2025-07-10T10:15:39.000+01:00
diff --git a/lua/codecompanion/strategies/chat/watchers.lua b/lua/codecompanion/strategies/chat/watchers.lua
@@ -83,6 +83,11 @@ function Watchers:get_changes(bufnr)
   if not self.buffers[bufnr] then
     return false, nil
   end
+  if not api.nvim_buf_is_valid(bufnr) then
+    -- special case for unlisted buffers
+    self:unwatch(bufnr)
+    return true, nil
+  end
   local buffer = self.buffers[bufnr]
   local current_content = api.nvim_buf_get_lines(bufnr, 0, -1, false)
   local current_tick = api.nvim_buf_get_changedtick(bufnr)
@@ -141,6 +146,12 @@ function Watchers:check_for_changes(chat)
             content = fmt([[<attachment filepath="%s" buffer_number="%s">%s</attachment>]], filename, ref.bufnr, delta),
           }, { visible = false })
         end
+      elseif has_changed then
+        -- buffer is now invalid
+        chat:add_message({
+          role = config.constants.USER_ROLE,
+          content = fmt([[buffer %d has been removed.]], ref.bufnr),
+        }, { visible = false })
       end
     end
   end
diff --git a/tests/strategies/chat/test_watcher.lua b/tests/strategies/chat/test_watcher.lua
@@ -187,6 +187,20 @@ T["Watchers"]["ignores changes after unwatching"] = function()
   h.eq(old_content, nil)
 end
 
+T["Watchers"]["handles changes after buffer removal"] = function()
+  local watcher = Watcher.new()
+  local bufnr = vim.api.nvim_create_buf(false, true)
+
+  vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, { "line 1" })
+  watcher:watch(bufnr)
+
+  vim.api.nvim_buf_delete(bufnr, {})
+
+  local has_changed, old_content = watcher:get_changes(bufnr)
+  h.eq(has_changed, true)
+  h.eq(old_content, nil)
+end
+
 T["Watchers"]["handles prepending to start of buffer"] = function()
   local watcher = Watcher.new()
   local bufnr = vim.api.nvim_get_current_buf()
