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feat: improve IP RegExp to cover more cases #239

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Merged
af merged 2 commits into from
Oct 17, 2025
Merged

feat: improve IP RegExp to cover more cases #239

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cca9e58
feat: improve IP RegExp to cover more cases
slagiewka Oct 10, 2025
b2e1e54
Simplify ipv6 regex (trading off readability)
af Oct 13, 2025
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9 changes: 4 additions & 5 deletions src/validators.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -15,11 +15,10 @@ const isFQDN = (input: string) => {
}

// "best effort" regex-based IP address check
// If you want a more exhaustive check, create your own custom validator, perhaps wrapping this
// implementation (the source of the ipv4 regex below): https://github.com/validatorjs/validator.js/blob/master/src/lib/isIP.js
const ipv4Regex =
/^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$/
const ipv6Regex = /([a-f0-9]+:+)+[a-f0-9]+/
// If you want a more exhaustive check, create your own custom validator
const ipv4Regex = /^(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])(\.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])){3}$/
const ipv6Regex = /^(([0-9a-f]{1,4}:){7}[0-9a-f]{1,4}|([0-9a-f]{1,4}:)+:([0-9a-f]{1,4}:)*[0-9a-f]{1,4}|([0-9a-f]{1,4}:)*::([0-9a-f]{1,4}:)*[0-9a-f]{0,4}|::|(([0-9a-f]{1,4}:){1,6}|:):((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])\.){3}(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9]))(%[0-9a-z.\-:]+)?$/i

const isIP = (input: string) => {
if (!input.length) return false
return ipv4Regex.test(input) || ipv6Regex.test(input)
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4 changes: 4 additions & 0 deletions tests/validators.test.ts
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Expand Up @@ -76,6 +76,10 @@ test('host()', () => {
assertPassthrough({ FOO: 'localhost' }, spec)
assertPassthrough({ FOO: '192.168.0.1' }, spec)
assertPassthrough({ FOO: '2001:0db8:85a3:0000:0000:8a2e:0370:7334' }, spec)
assertPassthrough({ FOO: '::' }, spec) // Unspecifed IPv6 address RFC4291
assertPassthrough({ FOO: '::1' }, spec) // Loopback IPv6 address RFC4291
assertPassthrough({ FOO: 'fe80::a%en1' }, spec) // Scoped IPv6 address RFC6874
assertPassthrough({ FOO: '64:ff9b::1.1.1.1' }, spec) // NAT64 IPv4/IPv6 translation RFC6052

expect(() => cleanEnv({ FOO: '' }, spec, makeSilent)).toThrow()
expect(() => cleanEnv({ FOO: 'example.com.' }, spec, makeSilent)).toThrow()
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