fix: move cursor correctly with multi-line text edits

Closes #1123

lua/blink/cmp/completion/accept/init.lua

@@ -85,8 +85,10 @@ local function accept(ctx, item, callback)
       else
         table.insert(all_text_edits, item.textEdit)
         text_edits_lib.apply(all_text_edits)
-        -- TODO: should move the cursor only by the offset since text edit handles everything else?
-        ctx.set_cursor({ ctx.get_cursor()[1], item.textEdit.range.start.character + #item.textEdit.newText + offset })
+
+        local new_cursor = text_edits_lib.get_apply_end_position(item.textEdit)
+        new_cursor[2] = new_cursor[2] + offset
+        ctx.set_cursor(new_cursor)
       end
 
       -- Let the source execute the item itself

lua/blink/cmp/lib/text_edits.lua

@@ -199,4 +199,28 @@ function text_edits.clamp_range_to_bounds(range)
   return range
 end
 
+--- The TextEdit.range.start/end indicate the range of text that will be replaced.
+--- This means that the end position will be the range *before* applying the edit.
+--- This function gets the end position of the range *after* applying the edit.
+--- This may be used for placing the cursor after applying the edit.
+---
+--- TODO: handle multiple text edits since they can edit the text that comes
+--- before the current edit
+---
+--- @param text_edit lsp.TextEdit
+--- @return number[] (1, 0) indexed line and column
+function text_edits.get_apply_end_position(text_edit)
+  local lines = vim.split(text_edit.newText, '\n')
+  local last_line_len = #lines[#lines]
+  local line_count = #lines
+
+  local end_line = text_edit.range['end'].line + line_count - 1
+
+  local end_col = last_line_len
+  if line_count == 1 then end_col = end_col + text_edit.range['end'].character end
+
+  -- Convert from 0-indexed to (1, 0)-indexed to match nvim cursor api
+  return { end_line + 1, end_col }
+end
+
 return text_edits