Function expectToBeLeft

  • expectToBeLeft<E, A>(
        value: undefined | Either<E, A>,
    ): asserts value is Readonly<{ isRight: false; left: E }>

  • Asserts and narrows the type of the provided Either value to Left.

    Type Parameters

    • E
    • A

    Parameters

    • value: undefined | Either<E, A>

      The Either value to check

    Returns asserts value is Readonly<{ isRight: false; left: E }>

    Throws

    If the value is undefined or not a Left

Settings

Member Visibility