Async::RSpec

Provides useful RSpec.shared_contexts for testing code that builds on top of async.

Installation

$ bundle add async-rspec

Then add this require statement to the top of spec/spec_helper.rb

require 'async/rspec'

Usage

Async Reactor

Many specs need to run within a reactor. A shared context is provided which includes all the relevant bits, including the above leaks checks. If your spec fails to run in less than 10 seconds, an Async::TimeoutError raises to prevent your test suite from hanging.

require 'async/io'

RSpec.describe Async::IO do
	include_context Async::RSpec::Reactor
	
	let(:pipe) {IO.pipe}
	let(:input) {Async::IO::Generic.new(pipe.first)}
	let(:output) {Async::IO::Generic.new(pipe.last)}
	
	it "should send and receive data within the same reactor" do
		message = nil
		
		output_task = reactor.async do
			message = input.read(1024)
		end
		
		reactor.async do
			output.write("Hello World")
		end
		
		output_task.wait
		expect(message).to be == "Hello World"
		
		input.close
		output.close
	end
end

Changing Timeout

You can change the timeout by specifying it as an option:

RSpec.describe MySlowThing, timeout: 60 do
	# ...
end

File Descriptor Leaks

Leaking sockets and other kinds of IOs are a problem for long running services. Async::RSpec::Leaks tracks all open sockets both before and after the spec. If any are left open, a RuntimeError is raised and the spec fails.

RSpec.describe "leaky ios" do
	include_context Async::RSpec::Leaks
	
	# The following fails:
	it "leaks io" do
		@input, @output = IO.pipe
	end
end

In some cases, the Ruby garbage collector will close IOs. In the above case, it's possible that just writing IO.pipe will not leak as Ruby will garbage collect the resulting IOs immediately. It's still incorrect to not close IOs, so don't depend on this behaviour.

Allocations

This functionality was moved to rspec-memory.

Contributing

We welcome contributions to this project.

1. Fork it.
2. Create your feature branch (git checkout -b my-new-feature).
3. Commit your changes (git commit -am 'Add some feature').
4. Push to the branch (git push origin my-new-feature).
5. Create new Pull Request.