Enhancement/update critical flows with e2e test coverage

[MaxwellGarceau]

Description of the Change

Update E2E Cypress tests to cover all critical testing flows.

• Critical flows test plan
  • Detailed notes for each item

Enhancement/add mailchimp api client - #99

• Add a FE Mailchimp client to Cypress tests to verify Mailchimp account interactions. Ensures successful form submission and full integration testing.
• Use .env.test for env variables
• Add health check for tests if Mailchimp client is unable to make requests
• Modularize Cypress commands

‼️ Environment changes needed ‼️

• Need to generate an API key for the test Mailchimp user in the CI/CD pipeline.
• Need to attach that API key to CYPRESS_MAILCHIMP_API_KEY as a Github secret
• Need to attach the server prefix to CYPRESS_MAILCHIMP_API_SERVER_PREFIX as a Github secret

Closes #61
Closes #86

How to test the Change

Follow the E2E testing instructions in the readme to run the Cypress tests. In addition, these tests should run automatically as part of the projects CI/CD flow.

Changelog Entry

Added - New tests to cover E2E critical flows
Changed - Existing tests to more robustly cover E2E critical flows. Modularized reusable testing code.

Credits

Props @MaxwellGarceau

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.

[MaxwellGarceau]

Status

@jeffpaul and @dkotter E2E tests passing with headless Cypress 🙂 - npm run cypress:run

Critical flows checklist

I duplicated the critical flows checklist and added ✅, ⚠️, ‼️ as well as notes to designate ✅ completed tests, ⚠️ tests that we won't write E2E tests for or can't due to some limitation, ‼️ and tests that are disabled or can't be written due to a known bug.

Known problems

• We can't write tests that require verifying confirmation emails because we need an email server that allows querying the emails via API
• Sometimes when running Cypress in GUI mode the web browser will crash
• In Cypress GUI the test spec file will sometimes be 302 redirected back to the WP login. Clearing the session data solves the problem, but it's very frustrating
• Everything has been going well with the Mailchimp API, but as Darin mentioned in Update critical flows with e2e test coverage #61 (comment) we should keep an eye on possible failures due to throttling or rate limits from Mailchimp's API. The only restriction I could find was that we can't have more than 10 simultaneous requests.

Next Steps

• I'd like to make a revision to the original testing instructions for critical flows to add my notes regarding E2E tests in order to highlight areas that will need to be QA'd and UAT'd with more scrutiny.
• Environment variables we need available in Github
  • CYPRESS_MAILCHIMP_API_KEY - API generated key from the Mailchimp account tied to the user
  • CYPRESS_MAILCHIMP_API_SERVER_PREFIX - this value will be appended to the API key - e.g. "us19" - docs
• cypress-dotenv and .env.test - I added cypress-dotenv for easier local testing. I wanted to call this out in case anything extra is needed in the CI/CD pipeline.

After we add the environment variables for the API key I can fix any errors that come up in the CI/CD pipeline.