Function isNullish

isNullish(value: unknown): value is Nullish
Type guard that checks whether a value is nullish (null or undefined).
Parameters
- value: unknown
  The value to check
Returns value is Nullish
true if the value is null or undefined, false otherwise
Example
```
if (isNullish(user)) {
  console.log('User is not defined');
}

const values = [1, null, 2, undefined, 3];
const defined = values.filter(v => !isNullish(v)); // [1, 2, 3]
```
- Defined in type/nullable.ts:42