apps-script-utils 2.1.1 Help

requireUndefined

function requireUndefined(value: unknown, message: string = "Expected undefined."): undefined;

The test is typeof value === "undefined", which is safe for a variable that was never declared, unlike a bare comparison.

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

value

unknown

The value to validate.

message (optional) = "Expected undefined."

string

The message of the exception. A default is used when omitted.

Returns

undefined — the same value, typed as undefined.

Throws

Exception

Condition

IllegalArgumentException

the value is not undefined.

Examples

What passes and what does not

requireUndefined(undefined); // => undefined requireUndefined(null); // throws IllegalArgumentException requireUndefined(0); // throws IllegalArgumentException

See also

Source

src/lang/base/requireUndefined.ts

23 September 2026
requireSymbolrequireUrl

This documentation was generated with AI (Claude) from the library's source code.