Mongoose - Why we make “mongoose.Promise = global.Promise” when setting a mongoose module?

Question

I'm working with Mongoose. I have seen a lot of developers make the following command:

mongoose.Promise = global.Promise;

Then I was curious to see what is the original value of mongoose.Promise. I have entered in my editor the following command:

const mongoose = require("mongoose"); 

console.log("promise: ", mongoose.Promise);

My console returned me :

promise: function Promise() { [native code] }

Okay, so why make the command mongoose.Promise = global.Promise since the Mongoose's promise already returns a native code? I don't understand the point if someone can help us to understand, would be great,

Thanks

Answer 1

Mongoose 4 relied on its own promise implementation, mpromise.Mongoose. Promise wasn't necessarily Promise global.

Answer 2

If we want to use mongoose in different position inside the codes it must be seen as global mode, that's why we need to set mongoose as :

mongoose.Promise = global.Promise;