const enum ErrorCode {
    NONE,
    PORT_BUSY,
    NAME_EXISTS
}

type ErrorMessage = {
    readonly code: ErrorCode;
    readonly message: string;
};

interface ENone extends ErrorMessage {
    code: ErrorCode.NONE;
}

interface EPortBusy extends ErrorMessage {
    code: ErrorCode.PORT_BUSY;
}

interface ENameExists extends ErrorMessage {
    code: ErrorCode.NAME_EXISTS;
}

const createContainer = (): [number | null, EPortBusy | ENameExists | ENone] => {
    if (Date.now() === 3) {
        return [3, { code: ErrorCode.NAME_EXISTS, message: 'name already exists' }];
    }
    return [null, { code: ErrorCode.PORT_BUSY, message: 'port is busy' }];
};


const pipeline = (): number => {
    const [res, err] = createContainer();
    if (res) {
        return 3;
    }
    switch (err.code) {
        case ErrorCode.PORT_BUSY: {
            return 0;
        }
        case ErrorCode.NAME_EXISTS: {
            return 2;
        }
        case ErrorCode.NONE: {
            return 3;
        }
    }
};