I'd like to whitelist domains and I have this list as

(domain1|domain2)

However, it will still match to

ci.domain1

/

I'm writing the code in node.js

Here's the code

new RegExp('(domain1|domain2)', 'igm').test('ci.domain1');

I'd like to whitelist domains and I have this list as

(domain1.|domain2.)

However, it will still match to

ci.domain1.

https://regex101./r/A2IOJE/1/

I'm writing the code in node.js

Here's the code

new RegExp('(domain1.|domain2.)', 'igm').test('ci.domain1.');

• javascript
• regex

2 Answers 2

You just need to add ^ (start of string) & $ (end of string):

/^(domain1.|domain2.)$/

console.log(
new RegExp('^(domain1.|domain2.)$', 'igm').test('ci.domain1.'),
new RegExp('^(domain1.|domain2.)$', 'igm').test('domain1.'),
new RegExp('^(domain1.|domain2.)$', 'igm').test('domain2.')
)

With anchors and optional www matching at the start you can use this regex:

/^(?:www\.)?(?:domain1|domain2)\.$/i

Also dot before needs to be escaped to avoid matching any character.

RegEx Demo

RegEx Breakup:

• ^: Start
• (?:www\.)?: Match optional www at the start of domains
• (?:domain1|domain2): Match domain1 or domain2
• \.: Match literal text .
• $: End