Add test to verify docker images build

[KieranHolroyd]

Currently fails on a number of the test cases, I'm not currently sure how to programatically fix this however, as it seems to be based on the underlying frameworks requiring certain files or folders to exist in order to complete the application build step. It might be worth considering pulling the latest version of whatever "starter project" these test candidates offer, removing any Dockerfile possibly shipped with the starter project, building it with the tool then verifying its correctness.

This pull request is not ready to be merged, I'm interested in feedback as to how this could be made to work easily with possible future test cases in mind.
(it seems my formatter changed a few things, which may go against code style, oops)

[rubys]

The "sister" project to this, dockerfile-rails does start from scratch and uses rails to generate an application. It even includes a single "system test" which launches an application runs the system tests contained within that application. As that is slow, this is only done on one application.

[rubys]

I wonder if the docker setup build action would help?

https://github.com/rubys/dockerfile-rails/blob/main/.github/workflows/system-test.yml#L8-L8

[KieranHolroyd]

I certainly had some issues getting docker images to build on actions, but pending this job not exiting early (the test will fail on 5 counts). I think it works properly

The next step would be to find some way of bootstrapping the projects to a buildable state for each test case, as this is currently not the case so the builds fail at the npm run build step or yarn/pnpm equivilant.

Update: it ran fully, however failed after running the tests with exit code 5, I'll be honest and say I have no idea why, this will require more debugging. Got stuff to be doing now however so that will have to wait unless someone else would like to have a go

[KieranHolroyd]

Ok, so after some research I found this issue.
It turns out that the exit code 0-255 is the number of failing tests, I tested this and it is apparently the case.

This means that all the previous test cases failing with exit code 5, just have 5 failing tests which is correct, problem solved?

(edit) I also ran this locally and caused 7 failed cases, checking the exit code, it was also 7.

[rubys]

Since all tests are passing, merge when you feel comfortable.