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Let's say you have a method called myMethod in the module myModule which is looking like this:

function myMethod() 
 return 5;

module.exports.myMethod = myMethod;

Now if I want to stub this method to return 2 instead of 5 with Sinon I would write

const myModule = require('path/myModule');
sinon.stub(myModule, 'myMethod').returns(2);

Now in the place where you actually call the method you happen to import the method like this with object destruction

const myMethod = require('path/myModule');
console.log(myMethod()); // Will print 5

If you do that, myMethod is actually not stubbed and won't return 2 but 5 instead.

If you instead require again the module and use the function from the required module it will work

const myModule= require('path/myModule');
console.log(myModule.myMethod()); // Will print 2

Is there anyone who has a solution to this other than just changing the way I import my functions?

The stubbed myMethod will have a different reference than the original method. In the destructuring example, you are setting the reference before it can be stubbed.

// cannot be stubbed
const myMethod = require('path/myModule');

// can be stubbed
const myModule = require('path/myModule');
myModule.myMethod();

Check out this similar question for more details

This is possible.

Just note that as soon as this runs:

const myMethod = require('./lib');

...it will remember whatever myMethod was at that moment.

So, you just have to make sure you set up the stub before that code runs.

So for this lib.js:

function myMethod() 
 return 5;

module.exports.myMethod = myMethod;

and this code.js:

const myMethod = require('./lib');
console.log(myMethod());

you would just need to do this:

const sinon = require('sinon');

const myModule = require('./lib');
sinon.stub(myModule, 'myMethod').returns(2); // set up the stub FIRST...
require('./code'); // ...THEN require the code (prints "2")