Constants
Decoders for constant and fixed values.
constant
constant(value: T): Decoder<T> (source)
Accepts only the given constant value.
const decoder = constant('hello');
// 👍
decoder.verify('hello') === 'hello';
// 👎
decoder.verify('this breaks'); // throws
decoder.verify(false); // throws
decoder.verify(undefined); // throwsalways
always(value: T): Decoder<T> (source)
Accepts anything, completely ignores it, and always returns the provided value instead.
This is useful to manually add extra fields to object decoders.
const decoder = always(42);
// 👍
decoder.verify('hello') === 42;
decoder.verify(false) === 42;
decoder.verify(undefined) === 42;
// 👎
// This decoder will never reject an inputOr use it with a function instead of a constant:
const now = always(() => new Date());
now.verify('dummy'); // e.g. new Date('2022-02-07T09:36:58.848Z')