Environment variables for configuration in Cypress

Introduction

Environment variables let you change settings without changing your test code. This helps tests run in different places easily.

You want to run the same test on different websites like staging and production.

You need to hide sensitive data like passwords or API keys from your test code.

You want to change test settings like timeouts without editing tests.

You run tests on different machines or CI servers with different setups.

You want to keep your test code clean and reusable.

Syntax

Cypress

Cypress.env('VARIABLE_NAME')

// or set in cypress.config.js
// env: { VARIABLE_NAME: 'value' }

Use Cypress.env('VARIABLE_NAME') to get the value of an environment variable in your test.

You can set environment variables in cypress.config.js or via command line when running tests.

Examples

Get the base URL from environment variables to use in tests.

Cypress

Cypress.env('baseUrl')

Visit the website URL stored in the environment variable baseUrl.

Cypress

cy.visit(Cypress.env('baseUrl'))

Set environment variables username and password in the config file.

Cypress

// cypress.config.js
module.exports = {
  e2e: {
    env: {
      username: 'testuser',
      password: 'mypassword'
    }
  }
}

Override or set environment variable baseUrl when running tests.

Cypress

// Run test with env variable from command line
npx cypress run --env baseUrl=https://example.com

Sample Program

This test uses environment variables for the website URL, username, and password. It visits the URL, fills in the login form, and checks if login was successful by verifying the URL.

Cypress

// cypress.config.js
const { defineConfig } = require('cypress')

module.exports = defineConfig({
  e2e: {
    env: {
      baseUrl: 'https://staging.example.com',
      username: 'user123',
      password: 'pass123'
    },
    setupNodeEvents(on, config) {
      // implement node event listeners here if needed
    }
  }
})

// cypress/e2e/login.cy.js
describe('Login Test', () => {
  it('logs in using environment variables', () => {
    cy.visit(Cypress.env('baseUrl'))
    cy.get('#username').type(Cypress.env('username'))
    cy.get('#password').type(Cypress.env('password'))
    cy.get('button[type=submit]').click()
    cy.url().should('include', '/dashboard')
  })
})

Important Notes

Environment variables help keep sensitive data out of your test code.

You can override environment variables from the command line for flexibility.

Always use Cypress.env() to access variables inside tests for consistency.

Summary

Environment variables let you configure tests without changing code.

Set variables in cypress.config.js or via command line.

Use Cypress.env('VAR_NAME') to get values in tests.

Practice

1. What is the main purpose of environment variables in Cypress testing?

easy

A. To configure tests without changing the test code

B. To write test assertions

C. To locate elements on the page

D. To generate test reports

Solution

1. Step 1: Understand environment variables role

   Environment variables store configuration data separately from code.

2. Step 2: Identify their use in Cypress

   They allow changing test settings without modifying test scripts.

3. Final Answer:

   To configure tests without changing the test code -> Option A

4. Quick Check:

   Environment variables = configure tests without code change [OK]

Hint: Environment variables store config, not test logic [OK]

Common Mistakes:

• Confusing environment variables with test assertions
• Thinking environment variables locate page elements
• Assuming environment variables generate reports

2. Which is the correct way to access an environment variable named API_URL inside a Cypress test?

easy

A. Cypress.env('API_URL')

B. process.env.API_URL

C. env.API_URL

D. getEnv('API_URL')

Solution

1. Step 1: Recall Cypress environment variable syntax

   Cypress uses Cypress.env('VAR_NAME') to access env variables.

2. Step 2: Match the correct syntax

   Only Cypress.env('API_URL') uses this correct method.

3. Final Answer:

   Cypress.env('API_URL') -> Option A

4. Quick Check:

   Access env vars with Cypress.env('VAR_NAME') [OK]

Hint: Use Cypress.env('VAR_NAME') to get env variables [OK]

Common Mistakes:

• Using Node.js process.env inside Cypress tests
• Trying to access env vars as plain variables
• Using incorrect function names like getEnv

3. Given the following cypress.config.js snippet:

export default defineConfig({
  env: {
    USERNAME: 'testUser',
    PASSWORD: 'pass123'
  }
})

What will cy.log(Cypress.env('USERNAME')) print during test execution?

medium

A. undefined

B. 'USERNAME'

C. 'testUser'

D. An error

Solution

1. Step 1: Check environment variable definition

   USERNAME is set to 'testUser' in cypress.config.js under env.

2. Step 2: Understand Cypress.env usage

   Cypress.env('USERNAME') returns the value 'testUser'.

3. Final Answer:

   'testUser' -> Option C

4. Quick Check:

   Cypress.env('USERNAME') = 'testUser' [OK]

Hint: Env vars return their set values, not keys [OK]

Common Mistakes:

• Expecting the key name instead of the value
• Assuming undefined if not set in test file
• Thinking Cypress.env throws error if variable exists

4. You wrote this code in your test:

const apiUrl = Cypress.env.API_URL;
cy.visit(apiUrl);

But the test fails with TypeError: Cannot read property 'API_URL' of undefined. What is the problem?

medium

A. cy.visit() cannot accept variables

B. The environment variable API_URL is not set in cypress.config.js

C. You must import Cypress before using it

D. You should use Cypress.env('API_URL') instead of Cypress.env.API_URL

Solution

1. Step 1: Identify how Cypress.env is accessed

   Cypress.env is a function, not an object, so use parentheses and quotes.

2. Step 2: Understand the error cause

   Using dot notation like Cypress.env.API_URL causes undefined error.

3. Final Answer:

   You should use Cypress.env('API_URL') instead of Cypress.env.API_URL -> Option D

4. Quick Check:

   Access env vars with Cypress.env('VAR_NAME') [OK]

Hint: Always call Cypress.env() as a function with string key [OK]

Common Mistakes:

• Using dot notation instead of function call
• Assuming env vars are properties, not accessed by function
• Ignoring error message details

5. You want to run Cypress tests with a different API URL without changing cypress.config.js. Which command line option correctly sets the environment variable API_URL to https://api.test.com?

hard

A. cypress run --config API_URL=https://api.test.com

B. cypress run --env API_URL=https://api.test.com

C. cypress open --env API_URL=https://api.test.com

D. cypress open --config API_URL=https://api.test.com

Solution

1. Step 1: Understand command line env variable setting

   Use --env VAR_NAME=value to set env variables temporarily.

2. Step 2: Identify correct command for running tests

   cypress run runs tests in headless mode; --env sets env vars.

3. Final Answer:

   cypress run --env API_URL=https://api.test.com -> Option B

4. Quick Check:

   Use --env to set env vars on command line [OK]

Hint: Use --env VAR=value with cypress run to override env vars [OK]

Common Mistakes:

• Using --config instead of --env for environment variables
• Trying to set env vars with cypress open command
• Confusing config options with env variables