How to test a function that generates a function?

Question

JavaScript

Good afternoon, I'm studying testing, basic pure functions and so on do not raise questions, but I can't quite understand how to test such functions:

exports.isExistsValidator = (model, field) => {
  return async (value) => {
    const result = await model.findOne({ where: { [field]: value } });
    if (!result) {
      return Promise.reject(`${model.name} with ${field} = ${value} does not exists`);
    }
  }
};

How to test?, except that:
1. "Must return an asynchronous function"

So I should create a model stub?

PS What is the name of the function that returns the function? (does not fit the definition of a Higher Order Function)