feat(builtin.buffers): enhance and bind delete_buffer action (#3145)

* feat(builtin.buffers): enhance and bind `delete_buffer` action

* change default bind and add docs

* [docgen] Update doc/telescope.txt
skip-checks: true

---------

Co-authored-by: Github Actions <actions@github>

lua/telescope/actions/init.lua

@@ -1176,9 +1176,22 @@ end
 ---@param prompt_bufnr number: The prompt bufnr
 actions.delete_buffer = function(prompt_bufnr)
   local current_picker = action_state.get_current_picker(prompt_bufnr)
+
   current_picker:delete_selection(function(selection)
     local force = vim.api.nvim_buf_get_option(selection.bufnr, "buftype") == "terminal"
     local ok = pcall(vim.api.nvim_buf_delete, selection.bufnr, { force = force })
+
+    -- If the current buffer is deleted, switch to the previous buffer
+    -- according to bdelete behavior
+    if ok and selection.bufnr == current_picker.original_bufnr then
+      local jumplist = vim.fn.getjumplist(current_picker.original_win_id)[1]
+      for i = #jumplist, 1, -1 do
+        if jumplist[i].bufnr ~= selection.bufnr and vim.fn.bufloaded(jumplist[i].bufnr) == 1 then
+          vim.api.nvim_win_set_buf(current_picker.original_win_id, jumplist[i].bufnr)
+          break
+        end
+      end
+    end
     return ok
   end)
 end

lua/telescope/builtin/__internal.lua

@@ -972,6 +972,9 @@ internal.buffers = function(opts)
       previewer = conf.grep_previewer(opts),
       sorter = conf.generic_sorter(opts),
       default_selection_index = default_selection_idx,
+      attach_mappings = function(_, map)
+        map({ "i", "n" }, "<M-d>", actions.delete_buffer)
+      end,
     })
     :find()
 end

lua/telescope/builtin/init.lua

@@ -339,6 +339,8 @@ builtin.man_pages = require_on_exported_call("telescope.builtin.__internal").man
 builtin.reloader = require_on_exported_call("telescope.builtin.__internal").reloader
 
 --- Lists open buffers in current neovim instance, opens selected buffer on `<cr>`
+--- - Default keymaps:
+---   - `<M-d>`: delete the currently selected buffer
 ---@param opts table: options to pass to the picker
 ---@field cwd string: specify a working directory to filter buffers list by
 ---@field show_all_buffers boolean: if true, show all buffers, including unloaded buffers (default: true)

lua/telescope/pickers.lua

@@ -535,6 +535,7 @@ function Picker:find()
   self.__original_mousemoveevent = vim.o.mousemoveevent
   vim.o.mousemoveevent = true
 
+  self.original_bufnr = a.nvim_get_current_buf()
   self.original_win_id = a.nvim_get_current_win()
   _, self.original_cword = pcall(vim.fn.expand, "<cword>")
   _, self.original_cWORD = pcall(vim.fn.expand, "<cWORD>")