Harden integration testing

[nateborr]

Investigate and choose an approach to harden Tock's browser-based integration testing, to minimize errors and toil due to library updates and changes in third-party platforms. If changes would be helpful, either implement them or open an issue to do that work as a follow-up.

Updating Puppeteer from version 19.11.1 to 23.6 for #1796 required some changes to keep the Jest/Puppeteer based integration tests running both in CircleCI and in a local Docker environment. These changes are working, but they've introduced some brittle elements:

• CircleCI is configured to run the tests using a legacy headless mode for Chrome, which the Chrome docs suggest will be removed in the future.
• In the Docker compose configuration used for local development, the "app" service was renamed to "application" to work around an issue in which Chrome's HTTP Strict Transport Security settings force requests to the app domain to use SSL. This is likely stable but it's an obscure naming dependency.

The relevant code changes were introduced in PR #1819. That PR's description includes additional technical context.

Some paths to consider:

• Switching from Chrome to Firefox or another browser
• Switching from Puppeteer to Playwright or another browser testing framework
• Investigating whether we need to bring our CircleCI configuration up to date
• Reducing differences between Tock's CI and local environments, potentially by moving away from CircleCI.
  • Moving from CircleCI will require compliance documentation changes.
  • It's possible to run a CircleCI job locally with its CLI tool, but currently that fails in our environment due to this issue when it attempts to launch multiple Docker containers in parallel.

[cantsin]

Excellent write up, thank you! Another thing we can consider is moving away from CircleCI entirely. I don't like that we are seeing discrepancy between local and CI tests. But that will require some compliance document changes as well. For now, let's sit on this. Thanks again!

[nateborr]

Thanks @cantsin , I've updated the issue description accordingly along with some context on our CircleCI setup.