If you want to match these examples, plus assuming quite a lot about what you want, this will match any white-space separated list of words, which allows brackets around words.

/^((^|[^^\d\W]\s|[^^]\]\s)(\[(?=[a-z]+\]))?[a-z]+\]?(\s(?=[a-z]))?)+$/i

Don't forget to trim your input 😉 Note: It has some flaws: Currently, JS does not support positive look-behinds and named capturing groups (or alternatively recursing groups), so it unfortunately also matches "[test] abc]" and might glitch in edge-cases.

You can go to Regex101 and run the unit tests I set up or test any string in the test area to see if everything is all right.

This seems like a job for the often overlooked \b meta, which acts has a word-delimiter identifier: works for punctuation, spaces, brackets (and also parenthesis, square brackets, ... you got the idea)

Here’s the pattern: \btest\b it’s as simple as that ;-)

What about just

^(\[test\]|test|test test)$

Otherwise you'll need to be more clear what you want to match.

You can test and explain it using regex101.com