Add some mult-program tests

Run the arbiter-actor in a separate program and do some basic tests to
make sure everything works - particularly, registration and
cancellation.

tests/conftest.py

@@ -8,6 +8,7 @@ import pytest
 import tractor
 
 
+pytest_plugins = ['pytester']
 _arb_addr = '127.0.0.1', random.randint(1000, 9999)
 
 

tests/test_multi_program.py

@@ -0,0 +1,77 @@
+"""
+Multiple python programs invoking ``tractor.run()``
+"""
+import sys
+import time
+import signal
+import subprocess
+
+import pytest
+import tractor
+
+
+from conftest import tractor_test
+
+
+def sig_prog(proc, sig):
+    "Kill the actor-process with ctr-c."
+    proc.send_signal(sig)
+    ret = proc.wait()
+    assert ret
+
+
+@pytest.fixture
+def daemon(loglevel, testdir, arb_addr):
+    cmdargs = [
+        sys.executable, '-c',
+        "import tractor; tractor.run_daemon(arbiter_addr={}, loglevel={})"
+        .format(
+            arb_addr,
+            "'{}'".format(loglevel) if loglevel else None)
+    ]
+    proc = testdir.popen(
+        cmdargs,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
+    assert not proc.returncode
+    time.sleep(0.2)
+    yield proc
+    # TODO: why sometimes does SIGINT not work on teardown?
+    sig_prog(proc, signal.SIGINT)
+
+
+def test_abort_on_sigint(daemon):
+    assert daemon.returncode is None
+    time.sleep(0.1)
+    sig_prog(daemon, signal.SIGINT)
+    assert daemon.returncode == 1
+    # XXX: oddly, couldn't get capfd.readouterr() to work here?
+    assert "KeyboardInterrupt" in str(daemon.stderr.read())
+
+
+@tractor_test
+async def test_cancel_remote_arbiter(daemon, arb_addr):
+    async with tractor.get_arbiter(*arb_addr) as portal:
+        await portal.cancel_actor()
+
+    time.sleep(0.1)
+    # the arbiter channel server is cancelled but not its main task
+    assert daemon.returncode is None
+
+    # no arbiter socket should exist
+    with pytest.raises(OSError):
+        async with tractor.get_arbiter(*arb_addr) as portal:
+            pass
+
+
+@tractor_test
+async def test_register_duplicate_name(daemon):
+    async with tractor.open_nursery() as n:
+        p1 = await n.start_actor('doggy')
+        p2 = await n.start_actor('doggy')
+
+        async with tractor.wait_for_actor('doggy') as portal:
+            assert portal.channel.uid in (p2.channel.uid, p1.channel.uid)
+
+        await n.cancel()