Execute Scripts in Incognito Mode

Description

(excerpt from Computer Hope)

Alternatively referred to as private browsing, InPrivate Browsing, or a private window, Incognito mode is an Internet browser setting that prevents browsing history from being stored. Normally, when you visit any web page, any text, pictures, and cookies required by the page are stored locally on your computer. Additionally, any searches or forms that are filled out may be stored in autocomplete fields. Incognito mode forgets this data when you close the browser window, or doesn’t store it at all.

Executing your Web automation in Incognito Mode has a few significant impact, including:

1. Cookies, cache, site data or history from your browser profile (from the normal browser mode) will not be considered during Incognito Mode, and hence will not impact the automation thereof.
2. Any web data such as cookies, cache, site data, etc. will not be stored in your browser profile. Any web history incurred during Incognito Mode will not be added to your browser profile either. At the end of the incognito session (i.e. when the incognito browser is closed), such information will be deleted and hence will not impact the subsequent Incognito sessions.
3. One may configure certain browser plugins or extensions to be disabled during Incognito mode, further limit or alter the behavior of the browsing experience.

The above points to the Incognito Mode as a great strategy to execute your Web automation within a pristine (in terms of browser) test harness. Such automation would more likely yield more consistent, more predictable behaviors and outcomes. Another way of describing the benefit is the reduction (or the eradication) of flaky tests. If you are interested, here are a few more links on flaky tests:

• Flaky tests, and how to reduce them
• Specific tips on how to reduce Selenium flaky tests
• Flaky Selenium tests

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How to…

To turn on Incognito Mode in Nexial, simply

1. set your target browser via the nexial.browser System variable, and
2. set nexial.browser.incognito System variable to true.

That’s it!

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Selenium-speak

For those of you interested in how setting the nexial.browser.incognito affects the underlying Selenium-related code, here’s the low-down:

Chrome

This is equivalent to adding a --incognito flag to the underlying chromedriver.

Firefox

This is equivalent to adding browser.privatebrowsing.autostart as true to underlying firefox profile, which in turn instructs the target Firefox binary to run in private mode.

Safari

(Not applicable) Like a private browsing session, an automation session always starts from a clean slate. It can’t access Safari’s browsing history, AutoFill data, or other sensitive information available in a normal browsing session. These isolated sessions also help to ensure that tests are unaffected by a previous test session’s persistent state.

More information available from Apple Developer site

Internet Explorer

This is equivalent to adding the following webdriver options:

• ie.browserCommandLineSwitches=-private
• ie.forceCreateProcessApi=true

Note: For private/incognito mode to work properly and without increment new process per each open tab, one must make a one-time adjustment to the Windows Registry on target test harness:

1. Open regedit
2. Point to HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
3. Edit or create a key named TabProcGrowth (dword) with a value of 0.

For more information, visit MSDN:: Opening a New Tab may launch a New Process with Internet Explorer 8.0

Edge

This is equivalent to adding InPrivate=true to underlying EdgeDriver. More details available here.

Some had reported that this does not work with specific (possibly older) Edge browser. As an alternative, one can achieve the “InPrivate” mode via the following steps (reference: https://github.com/florentbr/SeleniumBasic/issues/89):

1. Set your target browser to Edge by setting nexial.browser to edge.
2. From your script, open to about:InPrivate PRIOR to your target website.
3. After that, proceed with your automation as planned.