Add a basic `tractor.run()` test

tests/test_tractor.py

@@ -1,7 +1,10 @@
 """
 Actor model API testing
 """
+import time
+
 import pytest
+import trio
 from piker import tractor
 
 
@@ -10,14 +13,39 @@ def us_symbols():
     return ['TSLA', 'AAPL', 'CGC', 'CRON']
 
 
+@pytest.mark.trio
+async def test_no_arbitter():
+    """An arbitter must be established before any nurseries
+    can be created.
+
+    (In other words ``tractor.run`` must be used instead of ``trio.run`` as is
+    done by the ``pytest-trio`` plugin.)
+    """
+    with pytest.raises(RuntimeError):
+        with tractor.open_nursery() as nursery:
+            pass
+
+
+def test_local_actor_async_gen():
+    """Verify a simple async function in-process.
+    """
+    async def print_loop(actor):
+        for i in range(10):
+            await trio.sleep(0.1)
+
+    start = time.time()
+    tractor.run(print_loop)
+    # ensure the sleeps were actually awaited
+    assert time.time() - start >= 1
+
+
 @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:
+    async with tractor.find_actor('brokerd') as portals:
+        async with tractor.open_nursery() as nursery:
+            # only one per host address, spawns an actor if None
             if not portals:
                 # no brokerd actor found
                 portal = await nursery.start_actor(
@@ -28,7 +56,7 @@ async def test_rx_price_quotes_from_brokerd(us_symbols):
                         'clients': {},
                         'dtasks': set()
                     },
-                    main=None,
+                    main=None,  # don't start a main func - use rpc
                 )
 
             # gotta expose in a broker agnostic way...
@@ -53,5 +81,6 @@ async def test_rx_price_quotes_from_brokerd(us_symbols):
                 # await gen.asend(None)
                 # break
 
-        await nursery.cancel()
         # arbitter is cancelled here due to `find_actors()` internals
+        # (which internally uses `get_arbiter` which kills the root
+        # nursery on __exit__)