The test is not executed, it gives an error

I am testing the addition of products, I want to add 10 products, for this I use the https://www.npmjs.com/package/multer library.

My test:

describe('Test products', () => {
    describe('POST /api/products/add', () => {
        it(`Should create ${addProductCount} products with 0...1000 price`, (done) => {
            let operationCount = addProductCount;
            for (let i = 0; i < addProductCount; i++) {
                let product = utils.getFakeProduct(2, 1000);
                chai
                    .request(server)
                    .post('api/products/add')
                    .set('token', constants.merchantToken)
                    .field(product)
                    .attach('product_photos', './test/path/products/test1.jpeg', 'test1.jpeg')
                    .attach('product_photos', './test/path/products/test2.jpg', 'test2.jpg')
                    .attach('product_photos', './test/path/products/test3.png', 'test3.png')
                    .end((err, res) => {
                        operationCount--;
                        expect(res).have.status(200);
                        expect(res.body).have.property('message');
                        expect(res.body.message).to.be.equal('Product added');
                        if (operationCount == 0) {
                            done();
                        }
                    });
            }
        });
    });
});

When performing tests, I get an error:

TypeError: source.on is not a function
      at Function.DelayedStream.create (node_modules\delayed-stream\lib\delayed_stream.js:33:10)
      at FormData.CombinedStream.append (node_modules\combined-stream\lib\combined_stream.js:44:37)
      at FormData.append (node_modules\form-data\lib\form_data.js:74:3)
      at Test.RequestBase.field (node_modules\superagent\lib\request-base.js:406:23)
      at Test.RequestBase.field (node_modules\superagent\lib\request-base.js:387:12)
      at Context.field (test/productsTest.js:53:22)
      at process.topLevelDomainCallback (domain.js:120:23)

What is my problem? I do not use this function.