ScratchPad versus Channel in RubySpec


#1

Many tests use Channel to collect data that needs to be tested. For
example, the following in inspect_spec.rb.

compliant_on(:ruby) do
it “reports aborting on a killed thread” do
c = Channel.new
t = Thread.new { c << Thread.current.inspect; Thread.stop }
c.receive.should include(‘run’)
t.inspect.should include(‘sleep’)
Thread.critical = true
t.kill
t.inspect.should include(‘aborting’)
Thread.critical = false
end
end

However, there is also ScratchPad which serves the same purpose. Why are
there two ways of doing this, and which is the preferred one?

Also, (as we were discussing before), why does every test have to call
ScratchPad.clear before using it. Shouldn’t MSpec be doing this
automatically?

Thanks,
Shri


#2

K, ScratchPad clear: MSpec doesn’t provide any contracts. It is up to
the user to clear his own state. This also allows for a test to use
ScratchPad across multiple examples. ScratchPad is only meant to be a
formalized global variable.

Channel is actually a part of Rubinius’s standard library (IIRC).
Ideally, the tests don’t rely on anything more than basic language
features, so we should try to keep usage of Standard Library to a
minimum. I only use stdlib’s that are required for MSpec’s runner, such
as FileUtils.

JD
From: Shri B.
Sent: Wednesday, January 07, 2009 12:32 AM
To: Jim D.
Cc: removed_email_address@domain.invalid
Subject: ScratchPad versus Channel in RubySpec

Many tests use Channel to collect data that needs to be tested. For
example, the following in inspect_spec.rb.

compliant_on(:ruby) do
it “reports aborting on a killed thread” do
c = Channel.new
t = Thread.new { c << Thread.current.inspect; Thread.stop }
c.receive.should include(‘run’)
t.inspect.should include(‘sleep’)
Thread.critical = true
t.kill
t.inspect.should include(‘aborting’)
Thread.critical = false
end
end

However, there is also ScratchPad which serves the same purpose. Why are
there two ways of doing this, and which is the preferred one?

Also, (as we were discussing before), why does every test have to call
ScratchPad.clear before using it. Shouldn’t MSpec be doing this
automatically?

Thanks,
Shri