Regex: Allowlisting URL Top-Level-Domains

I'm looking for a regex that allowlists specific TLDs in the URL scheme. Most of my tests are passing except for ones that repeat the TLD:

Regex

^https:\/\/[^\/]+\.my-site\.com|cloud\/?.*?$

False Positive

https://qa.my-site.cloud.cloud/check-this-out?check-it-out=true

This is showing as a valid match according to the regex, but I want to exclude matches that have repeated TLDs (i.e. .cloud.cloud from the example above). How do I avoid the regex matching URLs with repeated TLDs? Adding a group and {1} did not solve the problem: ^https:\/\/[^\/]+\.my-site\.(?:com|cloud){1}\/?.*?$

Language being used is Javascript.

There are two issues:

1. You need to wrap alternation (|) in parentheses: (com|cloud) instead of com|cloud
2. The / should be required if there is a path to the URL

Here's a working regex:

^https:\/\/[^\/]+\.my-site\.(com|cloud)(\/.*?)?$

Try it.

You can use a positive lookahead assertion to ensure that the TLD only appears once in the domain:

^https:\/\/[^\/]+\.my-site\.(?=com|cloud)[^\/]*\/?.*?$

Explanation:

• ^https:\/\/[^\/]+\.my-site\. matches the start of the string, "https://" and everything up to ".my-site."
• (?=com|cloud) is a positive lookahead assertion that ensures the TLD is either "com" or "cloud"
• [^\/]*\/? matches the rest of the domain path, including the TLD, but not including any trailing slash (if there is one)
• .*?$ matches the rest of the URL, including any query parameters

Note that the TLDs are listed inside a non-capturing group (?:com|cloud), which means they will be treated as one option and not capture any matching groups.