As a software developer, I know how important it is to ensure that your web applications are working as intended without any bugs or issues. One of the most popular testing frameworks for web applications is Cypress, which is known for its ease of use and powerful features. In this article, I will be discussing one of the most important features of Cypress – Cypress Invoke and how it can be used to work with child windows.

Understanding Cypress Invoke and Child Windows #

Before we dive into the specifics of Cypress Invoke, let’s first understand what child windows are. Child windows are browser windows that are opened from a parent window. These windows can be opened either by clicking on a link or by using JavaScript. Child windows are commonly used for displaying pop-up windows, modal windows, and iframes.

Cypress Invoke is a powerful method that allows you to interact with elements inside child windows. With Cypress Invoke, you can execute JavaScript code inside the child window, interact with elements, and retrieve data. This method is particularly useful when working with iframes, pop-up windows, and other types of child windows.

Cypress Iframes: How They Work and Why They Matter #

Iframes are a type of child window that are embedded within a web page. They are commonly used to display content from a different domain, such as ads, videos, or social media widgets. Iframes can be tricky to work with because they are essentially separate web pages embedded within a parent web page.

To work with iframes using Cypress, you can use the cy.iframe() command. This command allows you to switch the context of your test to the iframe and interact with its elements using Cypress commands.

cy.iframe('#my-iframe').find('.my-element').click()

In the above example, we are using the cy.iframe() command to switch the context of our test to the iframe with the ID of my-iframe. We then use the find() command to locate an element with the class of my-element and click on it.

Cypress Get By ID: Navigating to Specific Elements in Child Windows #

When working with child windows, it is often necessary to locate specific elements within them. In Cypress, you can use the cy.get() command with an ID selector to locate elements within child windows.

cy.get(‘#my-element’, { withinSubject: cy.iframe(‘#my-iframe’) }).click()

In the above example, we are using the cy.get() command with the ID selector of my-element. We are also using the withinSubject option to specify that we want to locate the element within the iframe with the ID of my-iframe.

cy.visit and Cypress Iframes: A Comprehensive Guide #

When testing web applications, it is often necessary to navigate to different pages or URLs. In Cypress, you can use the cy.visit() command to navigate to a new page or URL. However, when working with iframes, you need to be careful about how you use this command.

To navigate to a new page within an iframe using Cypress, you can use the cy.visit() command within the context of the iframe.

cy.iframe(‘#my-iframe’).then(iframe => {  cy.wrap(iframe.contents().find(‘#my-link’)).click()})

In the above example, we are using the cy.iframe() command to switch the context of our test to the iframe with the ID of my-iframe. We then use the then() command to access the contents of the iframe and locate an element with the ID of my-link. Finally, we use the click() command to click on the link within the iframe.

Working with Cypress Popup Windows and Tabs #

Popup windows and tabs are another type of child window that you may encounter when testing web applications. Cypress provides several commands that allow you to work with popup windows and tabs.

cy.window().then(win => {  win.open(‘https://www.example.com’, ‘_blank’)})

In the above example, we are using the cy.window() command to access the global window object. We then use the open() method to open a new window or tab with the URL of https://www.example.com.

Cypress Get Href: Navigating to External Links in Child Windows #

When working with child windows, you may also need to navigate to external links. To do this in Cypress, you can use the cy.get() command with an href selector to locate the link and then use the click() command to navigate to the external URL.

cy.get(‘a[href=”https://www.example.com”]’, { withinSubject: cy.iframe(‘#my-iframe’) }).click()

In the above example, we are using the cy.get() command with an href selector to locate a link with the URL of https://www.example.com. We are also using the withinSubject option to specify that we want to locate the link within the iframe with the ID of my-iframe. Finally, we use the click() command to navigate to the external URL.

Cypress Navigate to URL: Opening Child Windows from the Parent Window #

In addition to navigating to URLs within child windows, you may also need to open child windows from the parent window. To do this in Cypress, you can use the cy.visit() command with the onBeforeLoad option to specify that you want to open the URL in a new window or tab.

cy.visit('https://www.example.com', {  onBeforeLoad(win) {    Object.defineProperty(win, 'open', {      value: cy.stub().as('windowOpen')    })  }})cy.get('#my-link').click()cy.get('@windowOpen').should('be.called')

In the above example, we are using the cy.visit() command to navigate to the URL of https://www.example.com. We are also using the onBeforeLoad option to define a new open() method on the global window object that we can then use to open new windows or tabs. Finally, we use the cy.stub() command to create a stub for the open() method, which we can then use to test that a new window or tab was opened when we click on the link with the ID of my-link.

Advanced Cypress Invoke Techniques with jQuery and JavaScript #

In addition to the basic techniques for working with child windows using Cypress Invoke, there are also more advanced techniques that you can use to interact with elements and execute JavaScript code.

One such technique is using the jQuery() method to access the jQuery object within the child window.

cy.iframe('#my-iframe').then(iframe => {  const $ = iframe.contents().find('body').jQuery  $('button').click()})

In the above example, we are using the cy.iframe() command to switch the context of our test to the iframe with the ID of my-iframe. We then use the then() command to access the contents of the iframe and locate the body element. Finally, we use the jQuery() method to access the jQuery object within the child window and click on a button element.

Handling Frame Busters: Tips and Tricks #

Frame busters are scripts that are designed to prevent a web page from being loaded within an iframe. These scripts can be a problem when working with iframes using Cypress.

To handle frame busters in Cypress, you can use the onBeforeLoad option with the window.parent property to ensure that the web page is loaded in the parent window instead of the iframe.

cy.visit('https://www.example.com', {  onBeforeLoad(win) {    Object.defineProperty(win, 'parent', {      value: cy.stub().as('windowParent')    })  }})cy.get('#my-link').click()cy.get('@windowParent').should('be.called')

In the above example, we are using the cy.visit() command to navigate to the URL of https://www.example.com. We are also using the onBeforeLoad option to define a new parent method on the global window object that we can then use to ensure that the web page is loaded in the parent window instead of the iframe. Finally, we use the cy.stub() command to create a stub for the parent() method, which we can then use to test that the web page was loaded in the parent window when we click on the link with the ID of my-link.

Best Practices for Working with Cypress Invoke and Child Windows #

When working with Cypress Invoke and child windows, there are several best practices that you should follow to ensure that your tests are accurate and reliable.

• Always use the cy.iframe() command to switch the context of your test to the iframe before interacting with its elements.
• Use the cy.get() command with an ID or href selector to locate specific elements within child windows.
• Use the cy.visit() command with the onBeforeLoad option to ensure that URLs are opened in the correct window or tab.
• Use the onBeforeLoad option with the window.parent property to handle frame busters.
• Use the withinSubject option with the cy.get() command to specify that you want to locate elements within a specific context.

Conclusion: The Power of Cypress Invoke in Your Testing Arsenal #

In conclusion, Cypress Invoke is a powerful method that allows you to work with child windows in your web application tests. By following the best practices outlined in this article, you can ensure that your tests are accurate and reliable. With Cypress Invoke in your testing arsenal, you can be confident that your web applications are working as intended without any bugs or issues.

If you want to learn more about automation testing with Cypress, join LSET today to access our comprehensive training program.