Add an initial `tractor` price streaming test

tests/test_tractor.py

@@ -0,0 +1,57 @@
+"""
+Actor model API testing
+"""
+import pytest
+from piker import tractor
+
+
+@pytest.fixture
+def us_symbols():
+    return ['TSLA', 'AAPL', 'CGC', 'CRON']
+
+
+@pytest.mark.trio
+async def test_rx_price_quotes_from_brokerd(us_symbols):
+    """Verify we can spawn a daemon actor and retrieve streamed price data.
+    """
+    async with tractor.open_nursery() as nursery:
+
+        # only one per host address, spawns an actor if None
+        async with tractor.find_actors('brokerd') as portals:
+            if not portals:
+                # no brokerd actor found
+                portal = await nursery.start_actor(
+                    'brokerd',
+                    ['piker.brokers.core'],
+                    statespace={
+                        'brokers2tickersubs': {},
+                        'clients': {},
+                        'dtasks': set()
+                    },
+                    main=None,
+                )
+
+            # gotta expose in a broker agnostic way...
+            # retrieve initial symbol data
+            # sd = await portal.run(
+            #     'piker.brokers.core', 'symbol_data', symbols=us_symbols)
+            # assert list(sd.keys()) == us_symbols
+
+            gen = await portal.run(
+                'piker.brokers.core',
+                '_test_price_stream',
+                broker='robinhood',
+                symbols=us_symbols,
+            )
+            # it'd sure be nice to have an asyncitertools here...
+            async for quotes in gen:
+                assert quotes
+                for key in quotes:
+                    assert key in us_symbols
+                break
+                # terminate far-end async-gen
+                # await gen.asend(None)
+                # break
+
+        await nursery.cancel()
+        # arbitter is cancelled here due to `find_actors()` internals