Introduce Cypress e2e testing for the WordPress plugin

[claytoncollie]

Is your enhancement related to a problem? Please describe.

We should introduce end-to-end testing with Cypress for the WordPress plugin so that it matches the same standards as our other open-source plugins and also makes sure we are shipping a solid, stable product to our clients and partners. These tests would be run in a matrix test again different versions of PHP and different versions of WordPress when the action is triggered.

Below are some examples of the tests we currently have at 10up.

Tests

https://github.com/10up/ElasticPress/tree/develop/tests/cypress

https://github.com/10up/simple-local-avatars/tree/develop/tests/cypress

https://github.com/10up/safe-redirect-manager/tree/develop/tests/cypress

Workflows

https://github.com/10up/ElasticPress/blob/develop/.github/workflows/cypress-tests.yml

https://github.com/10up/simple-local-avatars/blob/develop/.github/workflows/cypress.yml

https://github.com/10up/safe-redirect-manager/blob/develop/.github/workflows/cypress.yml

I am happy to make a pull request for this issue.

Designs

No response

Describe alternatives you've considered

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[nicholasio]

Thanks for opening this issue. @Manussakis recently started working on setting up a basic e2e test. For now, we're looking to set up a very basic test but with the infra to add more tests in the future.

Feel free to drop any feedback on #623