What is the replacement of express's res.send({ user: 'xyz' }); or res.end() in koa?

问题

I want to send the response with an error in my koa app when there is no sessionId.I explored But didn't get anything helpful for me to do the same. I also used return ctx.throw(401); for unauthorized but it is not good, ctx.throw(401); just sending the "unauthorized", I want to add some specific information and after adding just send the response to the client. can anyone suggest me what to do the same?

My code is:

index.validateKey = async (ctx, next) => {
    await new Promise((resolve, reject) => {
        var authorized = ctx.headers.sessionid ? true : false;
        if (!authorized) {
             return ctx.throw(401); //HERE , I want to send .
        }
        resolve();
    });
    await next();
}

回答1:

You can check sessionId in sync so no async await function is needed. Your middleware function can be like this.

async(ctx, next) => {
    var authorized = ctx.headers.sessionid ? true : false;
    if (!authorized) {
        return ctx.throw('session Id required', 401);; 
        /*HERE , You can send custom message and return.*/
    }
    /* call next middleware else*/
    await next();
})

来源：https://stackoverflow.com/questions/43085204/what-is-the-replacement-of-expresss-res-send-user-xyz-or-res-end-in