Cypress.Screenshot
The Screenshot API allows you set defaults for how screenshots are captured during .screenshot and automatic screenshots taken during test failures. You can set defaults for the following:
- Which parts of the screen to capture.
- Whether to scale your application under test in the screenshot.
- Whether to disable JavaScript timers and CSS animations when taking the screenshot.
- Whether to automatically take screenshots when there are run failures.
- Which, if any, elements to black out when taking the screenshot.
- Whether to wait for the Command Log to synchronize before taking the screenshot.
Syntax
Cypress.Screenshot.defaults(options)
Arguments
options (Object)
An object containing one or more of the following:
Option | Default | Description |
---|---|---|
blackout | [] | Array of string selectors used to match elements that should be blacked out when the screenshot is taken. Does not apply to runner captures. |
capture | 'fullPage' | Which parts of the Cypress Test Runner to capture. This value is ignored for element screenshot captures. Valid values are viewport , fullPage , or runner . When viewport , your application under test is captured in the current viewport. When fullPage , your application under test is captured in its entirety from top to bottom. When runner , the entire browser viewport, including the Cypress Command Log, is captured. For screenshots automatically taken on test failure, capture is always coerced to runner . |
disableTimersAndAnimations | true | When true, prevents JavaScript timers (setTimeout , setInterval , etc) and CSS animations from running while the screenshot is taken. |
scale | false | Whether to scale the app to fit into the browser viewport. This is always coerced to true for runner captures. |
screenshotOnRunFailure | true | When true, automatically takes a screenshot when there is a failure during cypress run . |
overwrite | false | Whether to overwrite duplicate screenshot files with the same file name when saving. |
onBeforeScreenshot | null | A callback before a (non-failure) screenshot is taken. For an element capture, the argument is the element being captured. For other screenshots, the argument is the $el . |
onAfterScreenshot | null | A callback after a (non-failure) screenshot is taken. For an element capture, the first argument is the element being captured. For other screenshots, the first argument is the $el . The second argument is properties concerning the screenshot, including the path it was saved to and the dimensions of the saved screenshot. |
Examples
Blackout elements before screenshot
Elements that match the specified selectors will be blacked out from the
screenshot, but only when the capture
option is viewport
. blackout
is
ignored if capture
option is runner
.
Cypress.Screenshot.defaults({
blackout: ['.secret-info', '[data-hide=true]'],
})
Take a screenshot of the entire Cypress browser window
By default, cy.screenshot()
only captures your
application under test. You may want it to capture the entire Cypress browser
for debugging purposes.
Cypress.Screenshot.defaults({
capture: 'runner',
})
Allow timers and animations to keep running
By default, JavaScript timers and CSS animations are disabled to try to prevent changes to your application under test while the screenshot is taken, but you can turn off this behavior.
Cypress.Screenshot.defaults({
disableTimersAndAnimations: false,
})
Disable screenshots on run failures
By default, Cypress automatically takes a screenshot when there is a failure
when running cypress run
, but you can disable this.
Cypress.Screenshot.defaults({
screenshotOnRunFailure: false,
})
Overwrite existing screenshots
By default, Cypress saves unique screenshot files for every screenshot that is
taken within the same test. You can choose to overwrite existing screenshots
with the same file name using the overwrite
option.
Cypress.Screenshot.defaults({
overwrite: true,
})
viewport
and fullPage
captures
Scale By default, scaling the application under test is turned off during when the
capture
option is viewport
to prevent differences between screenshots on
screens with different resolutions. You can turn scaling on and have your app
scaled like it is during normal use of Cypress. This is always coerced to true
if the capture
option is runner
.
Cypress.Screenshot.defaults({
scale: true,
})
onBeforeScreenshot
and onAfterScreenshot
Change the DOM using The onBeforeScreenshot
and onAfterScreenshot
callbacks provide an
opportunity to synchronously change the DOM to create a more consistent state
for the screenshot.
In this example, imagine there is a clock in your app showing the current time.
This can cause screenshots to be non-deterministic, which could create false
negatives when screenshot diffing. You can use onBeforeScreenshot
to hide the
clock and then show it again with onAfterScreenshot
.
Cypress.Screenshot.defaults({
onBeforeScreenshot($el) {
const $clock = $el.find('.clock')
if ($clock) {
$clock.hide()
}
},
onAfterScreenshot($el, props) {
const $clock = $el.find('.clock')
if ($clock) {
$clock.show()
}
},
})
onAfterScreenshot
callback
Get properties from the Cypress.Screenshot.defaults({
onAfterScreenshot($el, props) {
// props has information about the screenshot,
// including but not limited to the following:
// {
// path: '/Users/janelane/project/screenshots/my-screenshot.png',
// size: '15 kb',
// dimensions: {
// width: 1000,
// height: 660,
// },
// scaled: true,
// blackout: ['.foo'],
// duration: 2300,
// }
},
})
Notes
Where to put screenshot configuration
A great place to put this configuration is in the supportFile, since it is loaded before any test files are evaluated.
History
Version | Changes |
---|---|
8.7.0 | Added overwrite configuration option. |