refactor: use sub() everywhere that we should use it

Author: wincent

lua/wincent/commandt/init.lua

@@ -7,6 +7,7 @@ local is_integer = require('wincent.commandt.private.is_integer')
 local is_table = require('wincent.commandt.private.is_table')
 local keys = require('wincent.commandt.private.keys')
 local merge = require('wincent.commandt.private.merge')
+local sub = require('wincent.commandt.private.sub')
 
 local commandt = {}
 
@@ -313,7 +314,7 @@ local default_options = {
     fd = {
       command = function(directory, options)
         if vim.startswith(directory, './') then
-          directory = directory:sub(3, -1)
+          directory = sub(directory, 3)
         end
         if directory ~= '' and directory ~= '.' then
           directory = vim.fn.shellescape(directory)
@@ -337,7 +338,7 @@ local default_options = {
     find = {
       command = function(directory, options)
         if vim.startswith(directory, './') then
-          directory = directory:sub(3, -1)
+          directory = sub(directory, 3)
         end
         if directory ~= '' and directory ~= '.' then
           directory = vim.fn.shellescape(directory)
@@ -464,7 +465,7 @@ local default_options = {
     rg = {
       command = function(directory, options)
         if vim.startswith(directory, './') then
-          directory = directory:sub(3, -1)
+          directory = sub(directory, 3)
         end
         if directory ~= '' and directory ~= '.' then
           directory = vim.fn.shellescape(directory)

lua/wincent/commandt/private/match_listing.lua

@@ -5,6 +5,7 @@ local match_listing = {}
 
 local Window = require('wincent.commandt.private.window').Window
 local merge = require('wincent.commandt.private.merge')
+local sub = require('wincent.commandt.private.sub')
 
 local border_height = 2
 local prompt_height = 1 + border_height
@@ -64,13 +65,6 @@ local function len(str)
   return vim.str_utfindex(str, 'utf-32')
 end
 
--- Unicode-aware `sub` implementation.
-local function sub(str, start_char, end_char)
-  local start_byte = vim.str_byteindex(str, 'utf-32', start_char, false)
-  local end_byte = end_char and vim.str_byteindex(str, 'utf-32', end_char, false)
-  return str:sub(start_byte, end_byte)
-end
-
 local format_line = function(line, width, selected, truncate, get_icon)
   local prefix = selected and '> ' or '  '
 

lua/wincent/commandt/private/sub.lua

@@ -0,0 +1,11 @@
+-- SPDX-FileCopyrightText: Copyright 2025-present Greg Hurrell and contributors.
+-- SPDX-License-Identifier: BSD-2-Clause
+
+-- Unicode-aware `sub` implementation.
+local function sub(str, start_char, end_char)
+  local start_byte = vim.str_byteindex(str, 'utf-32', start_char, false)
+  local end_byte = end_char and vim.str_byteindex(str, 'utf-32', end_char, false)
+  return str:sub(start_byte, end_byte)
+end
+
+return sub