Exclude word from existing reqExp (javascript)

Question

There are working regExp: '^modules(/.*|$)',

How I can change it to exclude such paths as 'modules/../../ .types. ' ?

Answer 1

If you need to exclude file extensions, it can be done two quick ways.

---

If using the old JS regex engine (no lookbehind asserts):

^modules(/(?:(?!\.(?:ext1|ext2|ext3)[ \t]*$).)*|)$

https://regex101.com/r/fJFIPL/1

 ^ modules
 (                             # (1 start)
    /
    (?:
       (?!
          \. 
          (?: ext1 | ext2 | ext3 )
          [ \t]* $ 
       )
       . 
    )*
  | 
 )                             # (1 end)
 $

---

If using the new JS regex engine (variable lookbehind asserts):

^modules(/.*(?<!\.(?:ext1|ext2|ext3)[ \t]*$)|)$

https://regex101.com/r/wAlrNW/1

 ^ modules
 (                             # (1 start)
    / .* 
    (?<!
       \.
       (?: ext1 | ext2 | ext3 )
       [ \t]* $
    )
  | 
 )                             # (1 end)
 $