feat: add cancel command for use with auto_insert

related to #215

README.md

@@ -192,7 +192,7 @@ MiniDeps.add({
   -- When defining your own keymaps without a preset, no keybinds will be assigned automatically.
   --
   -- Available commands:
-  --   show, hide, accept, select_and_accept, select_prev, select_next, show_documentation, hide_documentation,
+  --   show, hide, cancel, accept, select_and_accept, select_prev, select_next, show_documentation, hide_documentation,
   --   scroll_documentation_up, scroll_documentation_down, snippet_forward, snippet_backward, fallback
   --
   -- "default" keymap
@@ -428,6 +428,8 @@ MiniDeps.add({
       -- 'preselect' will automatically select the first item in the completion list
       -- 'manual' will not select any item by default
       -- 'auto_insert' will not select any item by default, and insert the completion items automatically when selecting them
+      -- 
+      -- When using 'auto_insert', you may want to bind a key to the `cancel` command, which will undo the selection
       selection = 'preselect',
       -- Controls how the completion items are rendered on the popup window
       draw = {

lua/blink/cmp/accept/preview.lua

@@ -1,28 +1,25 @@
 --- @param item blink.cmp.CompletionItem
-local function preview(item, previous_text_edit)
+local function preview(item)
   local text_edits_lib = require('blink.cmp.accept.text-edits')
   local text_edit = text_edits_lib.get_from_item(item)
 
-  -- with auto_insert, we may have to undo the previous preview
-  if previous_text_edit ~= nil then text_edit.range = text_edits_lib.get_undo_range(previous_text_edit) end
-
   if item.insertTextFormat == vim.lsp.protocol.InsertTextFormat.Snippet then
     local expanded_snippet = require('blink.cmp.sources.snippets.utils').safe_parse(text_edit.newText)
     text_edit.newText = require('blink.cmp.utils').get_prefix_before_brackets_and_quotes(
       expanded_snippet and tostring(expanded_snippet) or text_edit.newText
     )
   end
 
+  local undo_text_edit = text_edits_lib.get_undo_text_edit(text_edit)
   local cursor_pos = {
     text_edit.range.start.line + 1,
     text_edit.range.start.character + #text_edit.newText,
   }
 
   text_edits_lib.apply({ text_edit })
-  vim.api.nvim_win_set_cursor(0, cursor_pos)
 
-  -- return so that it can be undone in the future
-  return text_edit
+  vim.api.nvim_win_set_cursor(0, cursor_pos)
+  return undo_text_edit
 end
 
 return preview

lua/blink/cmp/accept/text-edits.lua

@@ -7,6 +7,16 @@ function text_edits.apply(edits) vim.lsp.util.apply_text_edits(edits, vim.api.nv
 
 ------- Undo -------
 
+--- Gets the reverse of the text edit, must be called before applying
+--- @param text_edit lsp.TextEdit
+--- @return lsp.TextEdit
+function text_edits.get_undo_text_edit(text_edit)
+  return {
+    range = text_edits.get_undo_range(text_edit),
+    newText = text_edits.get_text_to_replace(text_edit),
+  }
+end
+
 --- Gets the range for undoing an applied text edit
 --- @param text_edit lsp.TextEdit
 function text_edits.get_undo_range(text_edit)
@@ -21,14 +31,28 @@ function text_edits.get_undo_range(text_edit)
   return range
 end
 
---- Undoes a text edit
+--- Gets the text the text edit will replace
 --- @param text_edit lsp.TextEdit
-function text_edits.undo(text_edit)
-  text_edit = vim.deepcopy(text_edit)
-  text_edit.range = text_edits.get_undo_range(text_edit)
-  text_edit.newText = ''
-
-  text_edits.apply({ text_edit })
+--- @return string
+function text_edits.get_text_to_replace(text_edit)
+  local bufnr = vim.api.nvim_get_current_buf()
+  local lines = {}
+  for line = text_edit.range.start.line, text_edit.range['end'].line do
+    local line_text = vim.api.nvim_buf_get_lines(bufnr, line, line + 1, false)[1]
+    local is_start_line = line == text_edit.range.start.line
+    local is_end_line = line == text_edit.range['end'].line
+
+    if is_start_line and is_end_line then
+      table.insert(lines, line_text:sub(text_edit.range.start.character + 1, text_edit.range['end'].character))
+    elseif is_start_line then
+      table.insert(lines, line_text:sub(text_edit.range.start.character + 1))
+    elseif is_end_line then
+      table.insert(lines, line_text:sub(1, text_edit.range['end'].character))
+    else
+      table.insert(lines, line_text)
+    end
+  end
+  return table.concat(lines, '\n')
 end
 
 ------- Get -------

lua/blink/cmp/config.lua

@@ -2,6 +2,7 @@
 --- | 'fallback' Fallback to the built-in behavior
 --- | 'show' Show the completion window
 --- | 'hide' Hide the completion window
+--- | 'cancel' Cancel the current completion, undoing the preview from auto_insert
 --- | 'accept' Accept the current completion item
 --- | 'select_and_accept' Select the current completion item and accept it
 --- | 'select_prev' Select the previous completion item
@@ -204,7 +205,7 @@ local config = {
   -- When defining your own keymaps without a preset, no keybinds will be assigned automatically.
   --
   -- Available commands:
-  --   show, hide, accept, select_and_accept, select_prev, select_next, show_documentation, hide_documentation,
+  --   show, hide, cancel, accept, select_and_accept, select_prev, select_next, show_documentation, hide_documentation,
   --   scroll_documentation_up, scroll_documentation_down, snippet_forward, snippet_backward, fallback
   --
   -- "default" keymap

lua/blink/cmp/init.lua

@@ -137,6 +137,15 @@ cmp.hide = function()
   return true
 end
 
+cmp.cancel = function()
+  if not cmp.windows.autocomplete.win:is_open() then return end
+  vim.schedule(function()
+    cmp.windows.autocomplete.undo_preview()
+    cmp.trigger.hide()
+  end)
+  return true
+end
+
 --- @param callback fun(context: blink.cmp.Context)
 cmp.on_open = function(callback) cmp.windows.autocomplete.listen_on_open(callback) end
 

lua/blink/cmp/keymap.lua

@@ -72,6 +72,7 @@ function keymap.setup(opts)
     local commands = {
       'show',
       'hide',
+      'cancel',
       'accept',
       'select_and_accept',
       'select_prev',

lua/blink/cmp/windows/autocomplete.lua

@@ -12,6 +12,8 @@
 --- @field auto_show boolean
 --- @field context blink.cmp.Context?
 --- @field event_targets blink.cmp.CompletionWindowEventTargets
+--- @field preview_undo_text_edit? lsp.TextEdit
+--- @field preview_context_id? number
 ---
 --- @field setup fun(): blink.cmp.CompletionWindow
 ---
@@ -25,6 +27,7 @@
 --- @field listen_on_position_update fun(callback: fun())
 ---
 --- @field accept fun(): boolean?
+--- @field undo_preview fun()
 ---
 --- @field select fun(line: number, skip_auto_insert?: boolean)
 --- @field select_next fun(opts?: { skip_auto_insert?: boolean })
@@ -200,15 +203,25 @@ function autocomplete.accept()
   if selected_item == nil then return end
 
   -- undo the preview if it exists
-  if autocomplete.preview_text_edit ~= nil and autocomplete.preview_context_id == autocomplete.context.id then
-    text_edits_lib.undo(autocomplete.preview_text_edit)
+  if autocomplete.preview_undo_text_edit ~= nil and autocomplete.preview_context_id == autocomplete.context.id then
+    text_edits_lib.apply({ autocomplete.preview_undo_text_edit })
+    autocomplete.preview_undo_text_edit = nil
+    autocomplete.preview_context_id = nil
   end
 
   -- apply
   require('blink.cmp.accept')(context, selected_item)
   return true
 end
 
+function autocomplete.undo_preview()
+  if autocomplete.preview_undo_text_edit ~= nil and autocomplete.preview_context_id == autocomplete.context.id then
+    text_edits_lib.apply({ autocomplete.preview_undo_text_edit })
+    autocomplete.preview_undo_text_edit = nil
+    autocomplete.preview_context_id = nil
+  end
+end
+
 function autocomplete.select(line, skip_auto_insert)
   autocomplete.set_has_selected(true)
   vim.api.nvim_win_set_cursor(autocomplete.win:get_win(), { line, 0 })
@@ -218,9 +231,12 @@ function autocomplete.select(line, skip_auto_insert)
   -- when auto_insert is enabled, we immediately apply the text edit
   if config.windows.autocomplete.selection == 'auto_insert' and selected_item ~= nil and not skip_auto_insert then
     require('blink.cmp.trigger.completion').suppress_events_for_callback(function()
-      if autocomplete.preview_context_id ~= autocomplete.context.id then autocomplete.preview_text_edit = nil end
-      autocomplete.preview_text_edit =
-        require('blink.cmp.accept.preview')(selected_item, autocomplete.preview_text_edit)
+      -- undo the previous preview if it exists
+      if autocomplete.preview_context_id == autocomplete.context.id and autocomplete.preview_undo_text_edit ~= nil then
+        require('blink.cmp.accept.text-edits').apply({ autocomplete.preview_undo_text_edit })
+      end
+
+      autocomplete.preview_undo_text_edit = require('blink.cmp.accept.preview')(selected_item)
       autocomplete.preview_context_id = autocomplete.context.id
     end)
   end