test: add crypto's setEngine test

[hiroppy]

Add tests for crypto.setEngine.
https://github.com/nodejs/node/blob/master/lib/crypto.js#L621

There is not a normal test because I did not have an idea that how to designate the engine(path or id) in the test :'-(
error:25066067:DSO support routines:DLFCN_LOAD:could not load the shared library

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

Affected core subsystem(s)

test

[jasnell]

This is a difficult one to test because it's entirely dependent on a number of factors that are not under our control (such as what other engines may be available on the OS being tested). It's definitely something that we should try to get fixed and tested tho so I really appreciate the effort here.

[jasnell]

@nodejs/crypto

[hiroppy]

Thank you for the answer. So leave only the exception tests.(verification tests for id and flags)

[mhdawson]

It also shows up as missing coverage in the code coverage numbers:https://coverage.nodejs.org/coverage-57f6a106fbc69a47/root/crypto.js.html ==> line 621

So good to add a test.

Ideally we would have some sort of dummy engine that we could actually set, but it seems like a good start to at least test the failure cases.

[mhdawson]

LGTM, provided CI passes.

[jasnell]

CI: https://ci.nodejs.org/job/node-test-pull-request/5874/

[jasnell]

Failures in CI appear to be unrelated but just in case: https://ci.nodejs.org/job/node-test-pull-request/5888/

[shigeki]

I think we can make tests for both static and dynamic engines by adding new crypto.getEngineList() API. I can submit a PR soon. How about it?

[jasnell]

That would be worthwhile, I think.
I was also wondering about the feasibility of having a non-op engine in our tests that could be used but I've never implemented an openssl crypto engine so have no idea how feasible that is ;-)

[shigeki]

Here is WIP of my PR in 0312f084d43e220c0448f80c6144a3d1f8877426 for crypto.getEngineList().
We can check static engine by looking for the engine id of dynamic that is included by default.
I also add a node_test_engine module in the test fixture to check dynamic loading. But gyp is very platform dependent. I have to check them all on CI.

[jasnell]

Updates on this one?

[shigeki]

This was already fixed in #11143. Closing.