How to share variable values in Cypress

In Cypress, sharing variables can be achieved through several different methods. Here are several ways to share variables across multiple test cases:

1. Using Cypress's Global State Object Cypress.env

The Cypress.env method allows setting and retrieving environment variables within tests. Environment variables set via this method are available throughout the entire test run and can be shared across different test cases.

javascript
// Set environment variable
Cypress.env('myVariable', 'someValue');

// Retrieve environment variable in different test cases
var mySharedVariable = Cypress.env('myVariable');

2. Using JavaScript's Global Variables

You can create a .js file within the cypress/support folder and declare variables in its top-level scope. For example, create globals.js:

javascript
// In cypress/support/globals.js
let globalVariable = null;

module.exports = {
  setGlobalVariable(value) {
    globalVariable = value;
  },
  getGlobalVariable() {
    return globalVariable;
  },
};

Then, import this module in cypress/support/index.js:

javascript
// In cypress/support/index.js
import './globals';

Now, you can use setGlobalVariable and getGlobalVariable in any test case to set and retrieve global variables.

3. Using before or beforeEach Hooks

If variables are set within before or beforeEach hooks and you want to share them across multiple it test cases within the same describe block, you can use the closure of these hooks to store the variables.

javascript
describe('Test Suite', () => {
  let sharedVariable;

  before(() => {
    // Set variable before the test suite starts; it will be shared in subsequent test cases
    sharedVariable = 'shared value';
  });

  it('Test Case 1', () => {
    // Use sharedVariable
    cy.log(sharedVariable);
  });

  it('Test Case 2', () => {
    // Use sharedVariable again
    cy.log(sharedVariable);
  });
});

4. Using Custom Cypress Commands

By defining custom commands in cypress/support/commands.js, you can store and access variables across test cases.

javascript
// Define custom commands
Cypress.Commands.add('setSharedVariable', (value) => {
  Cypress.env('sharedVariable', value);
});

Cypress.Commands.add('getSharedVariable', () => {
  return Cypress.env('sharedVariable');
});

// Use custom commands
cy.setSharedVariable('someValue');
cy.getSharedVariable().then((value) => {
  // Use value
});

Using these methods allows sharing variables across multiple test cases in Cypress, but they should be handled carefully to ensure that test independence and reliability are not compromised due to shared state.