In order to create a new session by Selenium WebDriver, the local end should provide the basic capabilities to the remote end. The remote end uses the same set of capabilities to create a session and describes the current session features.
WebDriver provides capabilities that each remote end will/should support the implementation. The following capabilities are supported by WebDriver:
This capability is used to set the
browserName for a given session.
If the specified browser is not installed at the
remote end, the session creation will fail.
This capability is optional, this is used to set the available browser version at remote end. For Example, if ask for Chrome version 75 on a system that only has 80 installed, the session creation will fail.
When navigating to a new page via URL, by default Selenium will wait until the page has fully loaded before responding. This works well for beginners, but can cause long wait times on pages that load a large number of third party resources. Using a non default strategy can make test execution faster in cases like this, but can also introduce flakiness where elements on the page change position as elements load in and change size.
The page load strategy queries the document.readyState as described in the table below:
|normal||complete||Used by default, waits for all resources to download|
|eager||interactive||DOM access is ready, but other resources like images may still be loading|
|none||Any||Does not block WebDriver at all|
This identifies the operating system at the remote-end,
platformName returns the OS name.
In cloud-based providers,
platformName sets the OS at the remote-end.
This capability checks whether an expired (or)
TLS Certificate is used while navigating
during a session.
If the capability is set to
insecure certificate error
will be returned as navigation encounters any domain
certificate problems. If set to
true, invalid certificate will be
trusted by the browser.
All self-signed certificates will be trusted by this capability by default.
acceptInsecureCerts capability will have an
effect for the entire session.
session is imposed with a certain
interval, during which the user can control the behaviour
of executing scripts or retrieving information from the browser.
Each session timeout is configured with
combination of different
timeouts as described below:
Specifies when to interrupt an executing script in a current browsing context. The default timeout 30,000 is imposed when a new session is created by WebDriver.
Specifies the time interval in which web page needs to be loaded in a current browsing context. The default timeout 300,000 is imposed when a new session is created by WebDriver. If page load limits a given/default time frame, the script will be stopped by TimeoutException.
This specifies the time to wait for the implicit element location strategy when locating elements. The default timeout 0 is imposed when a new session is created by WebDriver.
Specifies the state of current session’s
user prompt handler.
Defaults to dismiss and notify state
This defines what action must take when a
user prompt encounters at the remote-end. This is defined by
unhandledPromptBehavior capability and has the following states:
This command alters the size and position of the current
browsing context window. This command acts as setter
getWindowRect command which accepts width, height,
x, y as optional arguments.
During automation, the current browsing context will be associated with window states, which describe the visibility of the browser window. The window states are
Setting Width or Height does not guaranteed that the resulting
window size will exactly match that which was requested. This is because
some drivers may not be able to resize in single-pixel increments.
Due to this, fetching the window state/details by
may not match the values set in the browser.
This new capability indicates if strict interactability checks should be applied to input type=file elements. As strict interactability checks are off by default, there is a change in behaviour when using Element Send Keys with hidden file upload controls.