Writing visual tests that use the Ultrafast Grid
In a previous article,
we described how to write an Eyes visual test using the
When using the
the Eyes SDK uses a desktop browser to capture and checkpoints.
The current article explains how to adapt this code so that is uses the
Ultrafast GridThe Ultrafast Grid is an Applitools service that offloads the generation of checkpoint images from the browser running in your test computer to a server running in the cloud. This greatly decreases the test run time, and also allows you to run a test on multiple browsers and emulated or simulated devices..
When using the Ultrafast Grid the
captures the DOM and other resource using the browser and sends it to the
Ultrafast Grid server,
where the checkpoint image is rendered concurrently with other checkpoints in your test suite.
Using the Ultrafast Grid considerably reduces test time and also enables you to test multiple browsers and mobile devices in a single test run, with almost no additional test time. For a full description of the Ultrafast Grid and what it can do for you, see the article Introduction to the Ultrafast Grid.
If you have existing legacy Eyes test which does not use the
then we recommend reading the article
Migrating code to use the Ultrafast Grid,
which provides a step-by-step guide to changing legacy code to use the Ultrafast Grid.
- Specifying the use of the Ultrafast Grid
- Specify which browsers and devices the Ultrafast Grid should render
These steps are typically done as part of the process of setting up the test suite.
The type of runner you pass to the Eyes constructor when you create it for each test determines if its checkpoints are rendered using the Ultrafast Grid or not.
object passed to the
constructor is used to configure the runner. The example shows the method
being passed. This option is used to limit the maximum number of Eyes tests that the runner will run simultaneously.
Increasing the concurrency value can allow your test suite to run faster, but the maximum number of tests that can run simultaneously depends on your Eyes plan, if concurrency has been allocated at a team level, and what other tests are being run on your account at the same time.
The integer value passed to the constructor limits the maximum number of Eyes tests that interact concurrently with the and the . Increasing the concurrency value can make your test suite run faster, but the maximum possible concurrency depends on your Eyes plan.
object stores the required values of Ultrafast Grid and Eyes attributes.
After the Eyes instance is created,
the Configuration object is applied to the Eyes instance using the method
The following snippet illustrates this,
configuring the Ultrafast Grid with a variety of desktop browsers and emulated devices.
It also adds some Eyes configurations that are typically common for all tests.
Some of the Eyes configurations which are recommended when using the
are not required here, since they are always enabled when using the
configuration$addbrowser: Render a page on any type of desktop browser, emulated mobile device or simulated iOS device.
configuration$addbrowsers: Render pages on a list of targets, each of which may be a desktop browser, an emulated mobile device or a simulated iOS device.
These methods take as parameters objects that define the type of rendering on the target browser or moble device:
desktopbrowserinfo$desktopbrowserinfo: The page is rendered using a desktop browser you specify using the type
iosdeviceinfo$iosdeviceinfo. The page is rendered using Chrome device emulation for the device specified by the type
chromeemulationinfo$chromeemulationinfo: The page is rendered on a Safari browser running on a mobile simulator that simulates the device specified by the type
The snippet provides an example of the use of
For full details regarding these methods and for more options available see the article
Ultrafast Grid Configuration.
You can add as many browser and device configurations as you require. Once you configure an Eyes instance to render on a set of browser configurations, they apply to all the tests that are run using that Eyes instance.
The browser baseline
- When adding a desktop browser (e.g. using the
configuration$addbrowsermethod), the Browser and Viewport size baseline attributes are defined by the parameters pf the method. The Operating system attributes will depend on the browser type - Microsoft browsers run on a Windows operating system and other browsers run on a Linux system.
- When adding an emulated mobile device (e.g. using the
configuration$adddeviceemulationmethod), the Browser attributes will be "Chrome", the Viewport size will be based on the screen size of that device, and the Operating system attributes will be the name of the native operating system for that device.
If browser configuration has a different layout, then you may very well need a separate baseline for each browser configuration. However, if two or more browser configurations are actually supposed to look the same, then you can use the Eyesbaseline environmentThe baseline environment is a name associated with a particular execution environment (OS, browser, viewport size). When you run a test against a particular baseline environment, Eyes matches the checkpoints against the baseline implied by the baseline environment instead of the baseline implied by the execution environment of the test. feature to do cross-browser testing by specifying a common baseline for multiple browser configurations. For details on how to do this see Setting up the baseline environment when using the Ultrafast Grid.
The code below shows a complete example of a test that runs using the Ultrafast Grid.
implement the 4 before/after methods following the pattern illustrated in this example. In the case of the
method, adapt the assignment to
to checks if the test passed or not using the facilities provided by your infrastructure.
If you run this code, in the test manager results you will see one set of test results for each of the desktop browsers and mobile devices that are configured in the test.