Function unwrapString

lib/assert.ts:127–132

(x: any, message?: string, ...extra_info: any[])

// Take a type value that is maybe a string and ensure it is
// T is syntax sugar for unwrapping to a string union
export function unwrapString<T extends string>(x: any, message?: string, ...extra_info: any[]): T {
    if (!isString(x)) {
        fail('String unwrap failed', message, extra_info);
    }
    return x as T;
}