Add an option to direct MyYoast requests to staging.

[herregroen]

There should be an option in the test helper which, if enabled, directs any request that would have gone to "https://my.yoast.com" instead to "https://staging-my.yoast.com".

The easiest way to achieve this would be to make the subdomain of all these URLs filterable in the plugin so that it can be replaced with "staging-my" by the test helper.

This would allow us to easily test features such as:

• New morphology releases
• Changes to licensing
• Features such as the new plugin installation flow which feature a lot of interaction between MyYoast and the plugin.

[diedexx]

We can use the requests-requests.before_request action to change the $url to the MyYoast staging domain if the original request is going to be sent to my.yoast.com. Here's an example how Jetpack uses this filter to achieve the same goal. https://github.com/Automattic/jetpack/blob/792b26b5539d07cc35fdd93567942f2ad481eef2/_inc/jetpack-server-sandbox.php#L63

[diedexx]

The option should be a dropdown of 5 options:

• live
• staging
• staging-plugins
• staging-platform
• local (my.yoast.test:3000)

[diedexx]

A new tag (1.2.5 or the next minor release) should be created and pushed with
git tag -a 1.2.5 git push origin master --tags

on yoast.com master: run composer require yoast/yoast-test-helper --dev and push this to master and merge this to all both staging-plugins and staging-platform with git checkout staging-plugins && git pull origin master.

[diedexx]

When testing this: when visiting the premium page in the plugin, a license request will be fired. If you have a site active on prod, and not active in dev you should quickly verify that the new option works and your license check is redirected to your local site