feat: Add back BATS for testing images

[MasonM]

Description

BATS was initially added to this repository in #802, but was then removed in #1339. This adds it back, and hooks it up to Github Actions.

This also fixes #1583, which happened due to a bug in the "Build image" step: the build context was set to the root project directory, which meant the COPY docker-entrypoint.sh /usr/local/bin/ instruction was copying the base docker-entrypoint.sh file into the Docker image instead of the one in the variant directory. Changing the context to the variant directory solves that.

Motivation and Context

#1579 (comment)

Testing Details

Link to run for this PR: https://github.com/nodejs/docker-node/actions/runs/1374569169

Example Output(if appropriate)

N/A

Types of changes

• Documentation
• Version change (Update, remove or add more Node.js versions)
• Variant change (Update, remove or add more variants, or versions of variants)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Others (non of above)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING.md document.
• All new and existing tests passed.

[MasonM]

Here's the fix for issue #1583, in case it wasn't clear from the PR description. The context should be the variant directory so it copies the right docker-entrypoint.sh file.

[SimenB]

I think this makes sense, thanks!

[nschonni]

I'm not sure I see the value of adding back BATS for these tests. If we do add it back, I think using the old install apt-install method would be better than a submodule.
I think added your other tests the same way as the others currently are there would make sense though

[MasonM]

@nschonni

If we do add it back, I think using the old install apt-install method would be better than a submodule.

Unfortunately, the version of "bats" in Ubuntu 20.04 is quite old and lacks support for the --verbose-run flag. I'm using that flag in this PR because it makes it easier to debug. This is one way BATS is superior to the old method: when tests fail, it clearly shows the expected output and the actual output, without any extra work.

I guess I could have Github Actions download the BATS source with curl and extract it, like this: https://github.com/hyperupcall/basalt/blob/d60b8a101ed3d9c2bb3cf6ae27286d944d03779c/.github/workflows/ci.yml#L35-L42

But that's more complicated than using a submodule.

[SimenB]

I think using a submodule makes sense since that's what the official docs recommend: https://bats-core.readthedocs.io/en/stable/tutorial.html#quick-installation.

I know I suggested it in #1588 (comment), but since it has no dependencies we could also just run it through npm exec. As long as we specify a version I don't see any security risk. It is up to date with 1.6.0 released 4 days ago, and maintained by the same person (I assume it's auto-published somehow, haven't dug into i)

[MasonM]

@SimenB Okay, I removed the submodule and changed it to use npx bats@1.6.0 instead.

[chorrell]

Is this still pending another review?

[SimenB]

I would like one 😀