About the big hole of wechat applet promise

 I have been using applets since I came into contact typeof Asynchronous operation in callback mode . However, with the in-depth contact, it is found that although this callback method can completely realize relevant operations, its readability and maintainability are not very high . And then I studied it ES6-Promise. I heard that wechat applet support was removed after a period of time , But I can still use it in small programs. I don't know why .

First, let's talk about my directory structure ：

First of all, I put the wx.request stay http.js It 's packed in

And then in fm_networking.js Make a layer of nesting

When I call outside, I find that I always leave resolve Then he left reject. This is a strange phenomenon for beginners . Then I found out from the root http.js Only left resolve. Then it must be fm_networking.js Problems in ？ however fm_networking.js China is only gone resolve. strange ！ In the same method, I copied what I wrote before typeof Code discovery is still very successful , The outside is only gone resolve. I can't think of my sister . Even I once thought it was impossible to nest like this .

Then when I checked the problem, I found that I commented on me set There is no problem with a line of code of the data .
Suddenly I remember a blog I read before Wang Hanyan's blog Written in ：

promise This is what happened reject in error There are no hints .
It's killing people .