Tests and Commands do not have access to common JS modules

Current behavior:

It is not possible to share Modules between custom commands and tests.

Desired behavior:

Variables set into modules from custom commands should be able to be read from tests.

Test code to reproduce

Is there a way to share JS modules between custom commands and Cypress tests ? Right now, when I try to share a variable defined in a JS module, set the value of the variable in the custom command and try to read it in a test, I get undefined ? For example,

jsmodule.js

export const A = {
a: null,

get a() {
    return this.a;
},

set a(a) {
    this.a = a;
},
};

commands.js

import {A} from './jsmodule.js';
Cypress.Commands.add('testing', () => {
A.a = 5;
});

Spec file

import {A} from './jsmodule.js'
beforeEach(function() {
cy.testing();
});
it('print',() => {
console.log(A.a);//undefined !!!
});

Versions

3.8.0 Electron

[bahmutov]

Here is what is going on, and I do not consider this a bug, just the way bundling happens.

You can find the supporting code in https://github.com/cypress-io/cypress-test-tiny/commit/08172373ff30d0e78544cc240c0a88155ecf035f

Anything bundled from the support file gets its own bundle. Anything imported from the spec file gets into second bundle. These two bundles are served for the spec

If you open the support bundle you will see the Username object from “globals”

If you open the spec bundle you will ALSO see the Username object` from “globals”

Each bundle has its own copy of “Username” imported from the file, changing a property in one does not change it in the other.

If you want to share data and object references between the support bundle nd the spec bundle, do it through the window object.

// support file
import { Username } from './globals'

window.Username = Username

Cypress.Commands.add('printName', () => {
  console.log('command globals name: %s', Username.name)
})

// spec file
const Username = window.Username

describe('globals', () => {
  it('shows username', () => {
    console.log('in spec username is "%s"', Username.name)
    console.log('now changed it to "foo"')
    Username.name = 'foo'
    console.log('in spec username is "%s"', Username.name)

    cy.printName()
  })
})

[gorru]

I’m not sure if I can write here. BTW… I’m trying to make a custom reporter with metadata added through custom methods called from tests. I saw the allure test report which use an Allure object shared between the test and the reporter but I can’t reproduce his behaviour. I also tried to create a plugin according to the post opening this thread but it doesn’t work. It seems that the global object of the reporter, the plugin and test execution are different so it’s not possibile to share data. Is this correct? There is a way to achieve data sharing between these items? Thanks in advance