nonException
function nonException<T>(value: T | Exception): value is T;
nonException(value) is the same test as !isException(value), written so that a guard clause reads as a sentence rather than as a negation.
The library's own hierarchy only. A plain Error does not qualify, which is exactly what makes the check useful in a catch block that has to tell the two apart.
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 an Exception; otherwise false.
In TypeScript the guard narrows value to T inside the branch.
Examples
What passes and what does not
nonException(new Error()); // => true
nonException({}); // => true
nonException(null); // => true
nonException(new IllegalArgumentException()); // => false
See also
Source
23 September 2026
This documentation was generated with AI (Claude) from the library's source code.