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Cypress App

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What you'll learn​

  • The names and purposes of the visual parts of Cypress
  • How to use the Selector Playground for targeting your page elements
  • How to debug tests using the built-in features of Cypress

Overview​

The Cypress desktop app has powerful features for creating, configuring, browsing, and most importantly running your tests. We'll touch on a few of the different functions before moving on to the Test Runner, the heart of the Cypress testing experience.

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Cypress Cloud integration

When you configure the open-source Cypress app to record tests to Cypress Cloud, you'll see data from your latest recorded runs directly in the Cypress app. This increased visibility into your test history allows you to debug your tests faster and more effectively, all within your local workflow.

The data used by these features is pulled from Cypress Cloud, so they will only reflect test results that were recorded.

If you're not sure whether you're logged in, you can always check using the profile control in the top right of the window.

The Launchpad​

The Launchpad

The Launchpad is your portal to Cypress, helping with onboarding, choosing a testing type and launching a browser.

Once you get comfortable with Cypress you might find you don't need the Launchpad any more. In this case you can run cypress open with the --browser and --component or --e2e options to go straight to the Spec Explorer.

The Spec Explorer​

The Spec Explorer

On choosing your browser in the Launchpad, you'll be presented with a list of your specs, their names, locations, and information about your latest recorded runs. Here you can launch specs by clicking them, create new blank or example specs, or search specs by name (handy for large test suites).

We've made the following spec data available directly in the Spec Explorer:

Last updated​

This column tells you when the code of this spec was last updated, using local file data from git or your own filesystem. It surfaces the change history of your tests, so you can quickly find the most relevant specs as you’re browsing your project.

This column will vary from machine to machine, as it reflects the state of the code as stored on that computer.

Latest runs​

This column shows the last time the spec was run, and the last four returned statuses. Results are scoped to your current git branch if available, falling back to the default branch if not, then finally all branches.

With this intelligence you can monitor, run, and fix tests locally within CI workflows, and then further dig into your results by clicking through to Cypress Cloud.

The runs data is sourced from Cypress Cloud (see note above) so it will be the same everywhere.

Average duration​

This column indicates the time taken to run the entire spec file, averaged over the last four runs, so that you can quickly identify and take action to improve the performance of your long-running tests.

Again, this analysis comes from Cypress Cloud.

Flake annotation​

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What is a flaky test?

A test is considered to be flaky when it can pass and fail across multiple retry attempts without any code changes.

Specs with flaky tests are flagged with an indicator beside the spec name. This means you can easily discern which areas of your application might result in an unreliable user experience.

The flake indicator will display if any tests in the given spec have been flaky in your latest runs (limited to 4). Hovering over the indicator will show a tooltip with the following analytics, based off the last 50 runs:

  • Rate (flaky runs divided by total runs)
  • Severity (flaky rate at a glance)
  • Last flaky (how many runs ago)

Clicking on the flake indicator will take you to the spec’s Flaky Test Analytics in Cypress Cloud.

Running Specs​

Spec Explorer

To run a spec, simply click the row with the spec you would like to run. You will be taken to the Test Runner and the spec will execute. You can narrow down the list of specs by typing into the search bar (1).

It is also possible to run multiple specs sequentially using the experimentalRunAllSpecs (2).

caution
Experimental Run All Specs

experimentalRunAllSpecs currently works with End to End Testing.

Running multiple specs sequentially is currently an experimental feature and it may change in the future. There are some known limitations outlined in this GitHub Discussion.

Running a large number of specs sequentially can consume more resources.

Project Runs​

Recorded Runs

This screen shows detailed information about the most recently recorded test runs across all git branches, latest first. This data comes from Cypress Cloud (see note above) so should be the same everywhere.

The title of each run is taken from the git commit message for that change, and clicking on it will take you to the corresponding run page in Cypress Cloud.

The Test Runner​

At the core of the app is the Test Runner itself. Cypress runs tests interactively, allowing you to see commands as they execute while also viewing the Application or Component Under Test, and exploring its DOM.

The Test Runner

Command Log​

The left-hand side of the Test Runner is a visual representation of your test suite. Each test block is properly nested and each test, when clicked, displays every Cypress command executed within the test's block as well as any commands executed in relevant before, beforeEach, afterEach, and after hooks.

Cypress app

Open files in your IDE​

There are some places in the Command Log that display a link to the relevant file where the code is located. Clicking on this link will open the file in your preferred file opener.

Open file in your IDE

Time traveling​

Each command, when hovered over, restores the Application or Component Under Test (right-hand side) to the state it was in when that command executed. This allows you to time travel back to previous states when testing.

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By default, Cypress keeps 50 tests worth of snapshots and command data for time traveling. If you are seeing extremely high memory consumption in your browser, you may want to lower the numTestsKeptInMemory in your Cypress configuration.

In the following example, hovering over the CONTAINS command in the Command Log changes the state of the AUT preview:

Hovering over the contains tab highlights the dom element in the App in the Cypress app

Cypress automatically travels back in time to a snapshot of when a hovered-over command resolved. Additionally, since cy.contains() finds DOM elements on the page, Cypress also highlights the element and scrolls it into view (to the top of the page).

Also note that as we hover over the CONTAINS command, Cypress reverts back to the URL that was present when the snapshot was taken.

The url address bar shows https://example.cypress.io/

Pinning snapshots​

Each command, when clicked on, displays extra information in the dev tools console. Clicking also pins the Application or Component Under Test (right-hand side) to its previous state, or snapshot, when the command executed.

In the following example, clicking on the CLICK command highlights it in purple, and does three other things worth noting:

A click on the click command in the Command Log with Cypress app labeled as 1, 2, 3

1. Pinned snapshots​

We have now pinned this snapshot. Hovering over other commands will not revert to them. This gives us a chance to manually inspect the DOM of our application under test at the time the snapshot was taken.

2. Event hitbox​

Since .click() is an action command, that means we also see a red hitbox at the coordinates the event took place.

3. Snapshot menu panel​

There is also a new menu panel. Some commands (like action commands) will take multiple snapshots: before and after. We can now cycle through these.

The before snapshot is taken prior to the click event firing. The after snapshot is taken immediately after the click event. Although this click event caused our browser to load a new page, it's not an instantaneous transition. Depending on how fast your page loaded, you may still see the same page, or a blank screen as the page is unloading and in transition.

When a command causes an immediate visual change in our application, cycling between before and after will update our snapshot. We can see this in action by clicking the TYPE command in the Command Log. Now, clicking before will show us the input in a default state, showing the placeholder text. Click after will show us what the input looks like when the TYPE command has completed.

Page events​

In addition to showing all the commands that were called, the command log also shows important events from your application or component when they occur. Notice these look different (they are gray and without a number).

Command log shows 'Page load --page loaded--' and 'New url https://example.cypress.io/'

Cypress logs out page events for:

  • Network XHR Requests
  • URL hash changes
  • Page Loads
  • Form Submissions

Instrument panel​

For certain commands like cy.intercept(), cy.stub(), and cy.spy(), an extra instrument panel is displayed above the test to give more information about the state of your tests.

Routes​

Routes Instrument Panel

Stubs​

Stubs Instrument Panel

Spies​

Spies Instrument Panel

Preview pane​

The right-hand side of the Test Runner is where the Application or Component Under Test is rendered.

Application Under Test
End-to-End Only
​

In E2E Testing, the right-hand side of the Test Runner is used to display the Application Under Test (AUT): the application that was navigated to using a cy.visit() or any subsequent routing calls made from the visited application.

In the example below, we wrote the following code in our test file:

cy.visit('https://example.cypress.io')

cy.title().should('include', 'Kitchen Sink')

In the corresponding application preview below, you can see https://example.cypress.io is being displayed in the right-hand side. Not only is the application visible, but it is fully interactive. You can open your developer tools to inspect elements as you would in your normal application. The DOM is completely available for debugging.

Application Under Test

The AUT also displays in the size and orientation specified in your tests. You can change the size or orientation with the cy.viewport() command or in your Cypress configuration. If the AUT does not fit within the current browser window, it is scaled appropriately to fit within the window.

The current size and scale of the AUT is displayed in the top right corner of the window.

The image below shows that our application is displaying at 1000px width, 660px height and scaled to 100%.

Viewport Scaling

Note: The right-hand side may also be used to display syntax errors in your test file that prevent the tests from running.

Errors

Note: Internally, the AUT renders within an iframe. This can sometimes cause unexpected behaviors explained here.

Component Under Test
Component Only
​

In Component testing, the right-hand side of the Test Runner is used to display the Component Under Test (CUT): the component that was mounted using the cy.mount() command.

In the following example, we have the following test in our spec file:

it('should have password input of type password', () => {
mount(<LoginForm />)
cy.contains('Password').find('input').should('have.attr', 'type', 'password')
})

In the corresponding Component Preview below, you can see the LoginForm component is being displayed in the right-hand side. Not only is the component visible, but it is fully interactable. You can open your developer tools to inspect elements as you would in your normal application. The DOM is completely available for debugging.

Cypress app showing mounted component and password assertion

The CUT also displays in the size and orientation specified in your tests. You can change the size or orientation with the cy.viewport() command or in your Cypress configuration. If the CUT does not fit within the current browser window, it is scaled appropriately to fit within the window.

The current size and scale of the CUT is displayed in the top right corner of the window.

The image below shows that our application is displaying at 500px width, 500px height and scaled to 100%.

Cypress app showing mounted component test viewport scale

Note: The right-hand side may also be used to display syntax errors in your spec file that prevent the tests from running.

Cypress app showing error as application under test

Note: Internally, the CUT renders within an iframe. This can sometimes cause unexpected behaviors explained here.

Selector Playground​

The Selector Playground is an interactive feature that helps you:

  • Determine a unique selector for an element.
  • See what elements match a given selector.
  • See what element matches a string of text.
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Needing a low code approach to create tests? Use Cypress Studio to record your browser interactions.

Uniqueness​

Cypress will automatically calculate a unique selector to use targeted element by running through a series of selector strategies.

Default Selector Priority​

  1. data-cy
  2. data-test
  3. data-testid
  4. data-qa
  5. id
  6. class
  7. tag
  8. attributes
  9. nth-child
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This is configurable

Cypress allows you to control how a selector is determined.

Use the Cypress.SelectorPlayground API to control the selectors you want returned.

Best practices​

You may find yourself struggling to write good selectors because:

  • Your application or component uses dynamic ID's and class names
  • Your tests break whenever there are CSS or content changes

To help with these common challenges, the Selector Playground automatically prefers certain data-* attributes when determining a unique selector.

Please read our Best Practices guide on helping you target elements and prevent tests from breaking on CSS or JS changes.

Finding selectors​

To open the Selector Playground, click the button next to the URL at the top of the Test Runner. Hover over elements in your app to preview a unique selector for that element in the tooltip.

Opening selector playground and hovering over elements

Click on the element and its selector will appear at the top. From there, you can copy it to your clipboard ( ) or print it to the console ( ).

Clicking an element, copying its selector to clipboard, printing it to the console

Running experiments​

The box at the top that displays the selector is also a text input.

Editing a selector​

When you edit the selector, it will show you how many elements match and highlight those elements in your app.

Type a selector to see what elements it matches

Switching to contains​

You can also experiment with what cy.contains() would yield given a string of text. Click on cy.get and switch to cy.contains.

Type in text to see which element it matches. Note that cy.contains() only yields the first element that matches the text, even if multiple elements on the page contain the text.

Experiment with cy.contains

Disabling highlights​

If you would like to interact with your app while the Selector Playground is open, the element highlighting might get in the way. Toggling the highlighting off will allow you to interact with your app more easily.

Turn off highlighting

Keyboard shortcuts​

There are keyboard shortcuts to quickly perform common actions from within Cypress.

KeyAction
rRerun tests
sStop tests
fBring focus to 'specs' window
Tooltips show keyboard shortcuts

Debugging​

In addition to the features already mentioned, Cypress comes with a host of debugging tools to help you understand a test. You can:

Errors​

Cypress prints several pieces of information when an error occurs during a Cypress test.

  1. Error name: This is the type of error (e.g. AssertionError, CypressError)
  2. Error message: This generally tells you what went wrong. It can vary in length. Some are short like in the example, while some are long, and may tell you exactly how to fix the error.
  3. Learn more: Some error messages contain a Learn more link that will take you to relevant Cypress documentation.
  4. Code frame file: This is usually the top line of the stack trace and it shows the file, line number, and column number that is highlighted in the code frame below. Clicking on this link will open the file in your preferred file opener and highlight the line and column in editors that support it.
  5. Code frame: This shows a snippet of code where the failure occurred, with the relevant line and column highlighted.
  6. View stack trace: Clicking this toggles the visibility of the stack trace. Stack traces vary in length. Clicking on a blue file path will open the file in your preferred file opener.
  7. Print to console button: Click this to print the full error to your DevTools console. This will usually allow you to click on lines in the stack trace and open files in your DevTools.
example command failure error

Console output​

Besides commands being interactive, they also output additional debugging information to your console.

Open up your Dev Tools and click on the GET for the .action-email class selector.

Cypress app with get command pinned and console log open showing the yielded element

We can see Cypress output additional information in the console:

  • Command (that was issued)
  • Yielded (what was returned by this command)
  • Elements (the number of elements found)
  • Selector (the argument we used)

We can even expand what was returned and inspect each individual element or even right click and inspect them in the Elements panel!

Special commands​

In addition to having a helpful UI, there are also special commands dedicated to the task of debugging, for example:

In the following example, we've added a cy.pause() command to this test:

describe('My First Test', () => {
it('clicking "type" shows the right headings', () => {
cy.visit('https://example.cypress.io')

cy.pause()

cy.contains('type').click()

// Should be on a new URL which includes '/commands/actions'
cy.url().should('include', '/commands/actions')

// Get an input, type into it and verify that the value has been updated
cy.get('[data-testid="action-email"]')
.type('[email protected]')
.should('have.value', '[email protected]')
})
})

Now, when the test runs, Cypress provides us a UI (similar to debugger) to step forward through each command in the test.

Cypress app shows label saying 'Paused' with Command Log showing 'Pause'

In action:

History​

VersionChanges
3.5.0Added keyboard shortcuts to Cypress
1.3.0Added Selector Playground