fix: preserve the alternate buffer (#20)

tests/test_util.lua

@@ -0,0 +1,19 @@
+local M = {}
+
+M.reset_editor = function()
+  require("oil").setup({})
+  vim.cmd.tabonly({ mods = { silent = true } })
+  for i, winid in ipairs(vim.api.nvim_tabpage_list_wins(0)) do
+    if i > 1 then
+      vim.api.nvim_win_close(winid, true)
+    end
+  end
+  vim.api.nvim_win_set_buf(0, vim.api.nvim_create_buf(false, true))
+  for _, bufnr in ipairs(vim.api.nvim_list_bufs()) do
+    if vim.api.nvim_buf_get_option(bufnr, "buflisted") then
+      vim.api.nvim_buf_delete(bufnr, { force = true })
+    end
+  end
+end
+
+return M