Add initial pubsub test

tests/test_pubsub.py

@@ -0,0 +1,81 @@
+from functools import partial
+from itertools import cycle
+
+import pytest
+import trio
+import tractor
+from async_generator import aclosing
+from tractor.testing import tractor_test
+
+
+def is_even(i):
+    return i % 2 == 0
+
+
+@tractor.msg.pub
+async def pubber(get_topics):
+    for i in cycle(range(10)):
+        topics = get_topics()
+        yield {'even' if is_even(i) else 'odd': i}
+        await trio.sleep(0.1)
+
+
+async def subs(which):
+    if len(which) == 1:
+        if which[0] == 'even':
+            pred = is_even
+        else:
+            pred = lambda i: not is_even(i)
+    else:
+        pred = lambda i: isinstance(i, int)
+
+    async with tractor.find_actor('streamer') as portal:
+        agen = await portal.run(__name__, 'pubber', topics=which)
+        async with aclosing(agen) as agen:
+            async for pkt in agen:
+                for topic, value in pkt.items():
+                    assert pred(value)
+
+
+def test_pubsub_multi_actor_subs(
+    loglevel,
+    arb_addr,
+):
+    async def main():
+        async with tractor.open_nursery() as n:
+            # start the publisher as a daemon
+            master_portal = await n.start_actor(
+                'streamer',
+                rpc_module_paths=[__name__],
+            )
+
+            even_portal = await n.run_in_actor('evens', subs, which=['even'])
+            odd_portal = await n.run_in_actor('odds', subs, which=['odd'])
+
+            async with tractor.wait_for_actor('odds'):
+                # block until 2nd actor is initialized
+                pass
+
+            # TODO: how to make this work when the arbiter gets
+            # a portal to itself? Currently this causes a hang
+            # when the channel server is torn down due to a lingering
+            # loopback channel
+            #     with trio.move_on_after(1):
+            #         await subs(['even', 'odd'])
+
+            # XXX: this would cause infinite
+            # blocking due to actor never terminating loop
+            # await even_portal.result()
+
+            await trio.sleep(1)
+            await even_portal.cancel_actor()
+            await trio.sleep(1)
+            await odd_portal.cancel_actor()
+
+            await master_portal.cancel_actor()
+
+    tractor.run(
+        main,
+        arbiter_addr=arb_addr,
+        rpc_module_paths=[__name__],
+    )