Unhandled promise rejection when an inner promise rejects

[Moneil97]

Using Promise 4.0.1, when I run the following code:

Promise(function(resolve, reject){
    throw "hello"
})
.fail(function(err){
    server.error("fail: " + err);
})

The fail handler catches the error and I get this output, which is what I would expect: ERROR: fail: hello

However, if I change the code so that it has an inner promise that throws:

Promise(function(resolve, reject){
    return Promise(function(resolve2, reject2){
        throw "hello"
    })
})
.fail(function(err){
    server.error("fail: " + err);
})

I would still expect the same output, but now I get Unhandled promise rejection: hello

I get the same behavior if I use a Promise.reject instead of throw:

Promise(function(resolve, reject){
    return Promise.reject("hello")
})
.fail(function(err){
    server.error("fail: " + err);
})

If I now add another fail handler:

Promise(function(resolve, reject){
    return Promise(function(resolve2, reject2){
        throw "hello"
    })
    .fail(function(err){
        server.error("inner fail: " + err);
        throw err;
    })
})
.fail(function(err){
    server.error("fail: " + err);
})

I get:

ERROR: inner fail: hello
Unhandled promise rejection: hello

The workaround I have found is to setup my promises like this:

Promise.resolve(null).then(function(_){
    return Promise(function(resolve2, reject2){
        throw "hello"
    })
    .fail(function(err){
        server.error("inner fail: " + err);
        throw err;
    })
})
.fail(function(err){
    server.error("fail: " + err);
})

now I get the output I would expect:

ERROR: inner fail: hello
ERROR: fail: hello