I want to have accurate form field validation for NEAR protocol account names (one for .near accounts and one for .testnet accounts).

/\.testnet$/gm is not quite a thorough enough regex for the testnet accounts.

The final 2 cases here should be marked as invalid (and there might be more cases that I don't know about):

example.testnet
sub.ex.testnet
something.testnet
shouldnotendwithperiod.testnet.
example.near
space should fail.testnet
touchingDotsShouldfail..testnet

See https://regex101.com/r/jZHtDA/1

I'm wondering if there is a well-tested regex for each type of account .near and .testnet) that I should be using in my validation.

Thanks.

CodePudding user response：

Something like this should do: /^(\w|(?<!\.)\.) (?<!\.)\.(testnet|near)$/gm

Breakdown

^                 # start of line
(
  \w              # match alphanumeric characters
  |               # OR
  (?<!\.)\.       # dots can't be preceded by dots
) 
(?<!\.)           # "." should not precede:
\.                # "."
(testnet|near)    # match "testnet" or "near"
$                 # end of line

Try the Regex out: https://regex101.com/r/vctRlo/1

CodePudding user response：

If you want to match word characters only, separated by a dot:

^\w (?:\.\w )*\.(?:testnet|near)$

Explanation

• ^ Start of string
• \w Match 1 word characters
• (?:\.\w )* Optionally repeat . and 1 word characters
• \. Match .
• (?:testnet|near) Match either testnet or near
• $ End of string

Regex demo

A bit broader variant matching whitespace character excluding the dot:

^[^\s.] (?:\.[^\s.] )*\.(?:testnet|near)$

Regex demo