nonValidVersion
function nonValidVersion(value: string): boolean;
nonValidVersion(value) is the same test as !isValidVersion(value), written so that a guard clause reads as a sentence rather than as a negation.
Dot-separated groups of digits, any number of them. A pre-release suffix, a leading v and an empty group are all rejected, so "1.2.3-beta" does not pass even though SemVer allows it.
isX and nonX answer a question and never interrupt control flow; requireX and requireNonX hand the value back or throw. The scheme is explained in Validation conventions.
Parameters
Parameter | Type | Description |
|---|---|---|
|
| The value to check. |
Returns
boolean — true when the value is not a version string; otherwise false.
Examples
What passes and what does not
nonValidVersion("1.2.3-beta"); // => true
nonValidVersion("v1.2"); // => true
nonValidVersion("1..2"); // => true
nonValidVersion("1"); // => false
nonValidVersion("1.2.3"); // => false
nonValidVersion("2026.01.15"); // => false
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.