Don't run integration tests on Falcon against TruffleRuby

[andrykonchin]

Hello.

TruffleRuby doesn't support Fiber.set_scheduler method so it will be great not to run tests (temporary) that involve this method call on TruffleRuby.

Right now only integration tests with Falcon rely on this method so here in this PR Falcon server is skipped in tests if Fiber.set_scheduler is not implemented.

Does it make sense?

[dentarg]

I guess this is in response to truffleruby-head (truffleruby 23.0.0-dev-a645f1b5) failing at https://github.com/sinatra/sinatra/actions/runs/3447564172/jobs/5753892737#step:5:14, right?

Sure, I guess it makes some sense

How come truffleruby (truffleruby 22.3.0) does not fail at https://github.com/sinatra/sinatra/actions/runs/3447564172/jobs/5753892621#step:5:19? Is falcon behaving differently on Ruby 3.0.x than 3.1.x?

[andrykonchin]

I guess this is in response to truffleruby-head (truffleruby 23.0.0-dev-a645f1b5) failing at https://github.com/sinatra/sinatra/actions/runs/3447564172/jobs/5753892737#step:5:14, right?

Yeah, exactly

Is falcon behaving differently on Ruby 3.0.x than 3.1.x?

Good question. I haven't noticed that specs passed on TruffleRuby 22.3.0 (CRuby 3.0).

Indeed, falcon behaves differently on Ruby 3.0 and Ruby 3.1. On Ruby 3.0 falcon depends on async 1.30.3 that doesn't use Fiber.set_scheduler. On Ruby 3.1 falcon depends on async 2.1.1 that depends on Fiber.set_scheduler.

[dentarg]

Is it possible to conditionally skip the test (so it is still seen in the test output) instead of deleting falcon from the servers array? Or do we error out too early for that?

[andrykonchin]

Yeah, tests fail too early - when a falcon server is run.

It happens before any integration test case is executed when IntegrationHelper is extending a file with tests and an extend_object callback is called:

sinatra/test/integration_helper.rb

Lines 121 to 128 in cafaab9

	def self.extend_object(obj)
	super
	base_port = 5000 + Process.pid % 100
	Sinatra::Base.server.each_with_index do |server, index|
	Server.run(server, base_port+index)
	end
	end

We may print some warning (when remove the falcon server from the servers list) to make this skipping more explicit. Will it be helpful?

[dentarg]

Sounds good to me

(FYI it is up to @jkowens to merge this as I don't have such access)

[andrykonchin]

@jkowens Could you please take a look and merge if it looks OK?

[andrykonchin]

Thank you!

[jkowens]

@andrykonchin thanks for the PR 👍

[dentarg]

Unfortunately, this check also skips falcon tests on MRI Ruby <3.0

$ chruby-exec 2.7.7 -- ruby -e 'p Fiber.respond_to?(:set_scheduler)'
false

falcon has an open requirement on async, async since version 2.0 requires Ruby >=3.1.1 (https://rubygems.org/gems/async/versions/2.0.0). It should be possible to still run these tests on Ruby 2.x, don't you think @andrykonchin? It will just run falcon using async 1.x

[eregon]

Right, so probably we should check explicitly for RUBY_ENGINE == "truffleruby" here.
TruffleRuby master has RUBY_VERSION 3.1 but doesn't support Fiber.set_scheduler yet.

[eregon]

So:

    if RUBY_ENGINE == "truffleruby" && !Fiber.respond_to?(:set_scheduler)

[andrykonchin]

I've prepared a PR with the fix (#1852).