fixes

[throwarray]

fixes #30

[throwarray]

Also, I'm curious what influenced the decision to remove (err,req,res,next) styled middleware. Perhaps it could be added again?

[hoangvvo]

Thanks @throwarray, I will review this PR soon. About the removal of (err, req, res, next):

• This allows continuation after the error is throw (If needed).

Previous

app.use(thisWork)
app.use(thisThrow) // throw here
app.use(thisWork1) // always skip
app.use(thisWork2) // always skip
app.use(anerrormiddleware) // handle error
// it's over, no way back

Now

app.use(thisWork)
app.use(thisThrow) // throw here
// simply calling .onError here and if next is called...
app.use(thisWork1) // may continue
app.use(thisWork2) // may continue

• It is awkwark always having to remember to put the error middleware at the end. If one forget:

app.use(thisWork) 
app.use(anerrormiddleware) // skip because there is no error
app.use(thisThrow) // throw here
app.use(thisWork1) // skip. uh oh where is the error middleware
app.use(thisWork2) // skip. oh no

• The only way this can determine if a middleware is an error middleware is by looking at its number of argument (4 of them). This is unreliable. What if I do not need (eslint will complain if next is never used) or forget next argument?

[hoangvvo]

I think one thing I miss is the convenience of using multiple error middleware.

app.use(errorLogger)
app.use(anotherErrorLoggerBcWhyNot)
app.use(errorResponse)

Perhaps a future version will accept an array of middleware for onError

[hoangvvo]

Thanks @throwarray, close in favor of #38

[throwarray]

@hoangvvo it does seem better to have it just be the apply method.
You should consider rewriting the 'next' function however because at the moment you have dangling promise errors. There's no catch on the next();. Or is that intentional?

[throwarray]

handler.get(async function () {
    await new Promise(function (resolve, reject) {
        setTimeout(function () { reject(new Error('error')) }, 100)
    })
})

[hoangvvo]

@throwarray This is definitely a bug. I just reproduce it locally. I will try to get a fix in