Function assertOptional

assertOptional<T>(
val: T | undefined,
...rest: [test: unknown, message?: string, ErrorClass?: ErrorConstructor],
): void
Asserts only if value is not undefined.

Provides conditional assertion that only executes when the value is defined. Useful for validating optional parameters or properties.
Type Parameters
- T
Parameters
- val: T | undefined
  value to test
- ...rest: [test: unknown, message?: string, ErrorClass?: ErrorConstructor]
Returns void
Example
```
function processUser(user: User, options?: ProcessOptions) {
    // Only assert options if they are provided
    assertOptional(options, isObject(options), 'Options must be an object');

    // Process user...
}
```
Example
```
const config = getConfig();
assertOptional(config.timeout, config.timeout > 0, 'Timeout must be positive');
```
- Defined in packages/utils/src/validation/assert.ts:217