Koa: ctx wasn't able to return after set in other callback function

[xinshouke]

I used the below code, the last line doesn't work in callback function of getall. there is no any response was return.

router.get('/',function (ctx, next) {
getall(function(result){
console.log('result===>',result);
ctx.body=result;
}
}
but I move the last line in out of the getall, it may return a response correctly.

[liangxingchen]

router.get('/', function(ctx, next) {
    return new Promise(function(resolve, reject) {
        getall(function(result) {
            console.log('result===>', result);
            ctx.body = result;
            resolve();
        })
    });
})

[liangxingchen]

koa send http response immediately when sync middleware called.
If there has async code in the middleware, the middleware should be async function or return a Promise

[jonathanong]

as @liangxingchen stated, you aren't doing control flow properly. middleware should always be returning a promise in koa v2

[xinshouke]

Yes, it works. Thanks