Match java-script files name using regex

Question

How I can match the following files name using regex.

index.js

[id].js

[...params].js

I tried this regex on my own but it seems to be not work

[a-z[]*.tsx


index.js // working
[id].js // not working
[...params].js // not working

Answer 1

If I understand correctly you want to validate JavaScript file names that have alphanumeric characters, and are optionally enclosed in [...] or [......]. Based on this you can use this regex, here with a number of tests:

[ 'index.js',
  '[id].js',
  '[foo].js',
  '[...params].js',
  '[..invalid1].js',
  '[invalid2.js',
  '#invalid3.js',
  'invalid^4.js',
  'invalid[5].js',
  '[(invalid)6].js',
  'invalid7.css',
].forEach(name => {
  let isValid = /^(?:[a-zA-Z0-9]+|\[(?:\.{3})?[a-zA-Z0-9]+\])\.js$/.test(name);
  console.log(name, '=>', isValid);
});

Output:

index.js => true
[id].js => true
[foo].js => true
[...params].js => true
[..invalid1].js => false
[invalid2.js => false
#invalid3.js => false
invalid^4.js => false
invalid[5].js => false
[(invalid)6].js => false
invalid7.css => false

Explanation of regex:

• ^ -- anchor pattern at start of string
• (?: -- start of non-capture group (for logical or)
  • [a-zA-Z0-9]+ -- 1+ alphanumeric chars
• | -- logical or
  • \[ -- literal [
  • (?:\.{3})? -- optional 3 dots
  • [a-zA-Z0-9]+ -- 1+ alphanumeric chars
  • \] -- literal ]
• ) -- end of non-capture group
• \.js -- literal .js
• $ -- anchor pattern at end of string

To learn more about regex language: https://twiki.org/cgi-bin/view/Codev/TWikiPresentation2018x10x14Regex