Add subscribe after close test

tests/test_local_task_broadcast.py

@@ -100,6 +100,29 @@ def test_stream_fan_out_to_local_subscriptions(
     trio.run(main)
 
 
+def test_subscribe_errors_after_close():
+
+    async def main():
+
+        size = 1
+        tx, rx = trio.open_memory_channel(size)
+        async with broadcast_receiver(rx, size) as brx:
+            pass
+
+        try:
+            # open and close
+            async with brx.subscribe():
+                pass
+
+        except trio.ClosedResourceError:
+            assert brx.key not in brx._state.subs
+
+        else:
+            assert 0
+
+    trio.run(main)
+
+
 def test_ensure_slow_consumers_lag_out(
     arb_addr,
     start_method,
@@ -129,7 +152,6 @@ def test_ensure_slow_consumers_lag_out(
 
                 async with brx.subscribe() as lbrx:
                     while True:
-                        #     await tractor.breakpoint()
                         print(f'{task.name}: starting consume loop')
                         try:
                             async for value in lbrx:
@@ -156,7 +178,7 @@ def test_ensure_slow_consumers_lag_out(
                             lag_time = time.time() - start
                             lags = laggers[task.name]
                             print(
-                                f'restarting slow ass {task.name} '
+                                f'restarting slow task {task.name} '
                                 f'that bailed out on {lags}:{value} '
                                 f'after {lag_time:.3f}')
                             if lags <= retries:
@@ -207,7 +229,8 @@ def test_ensure_slow_consumers_lag_out(
                     await brx.receive()
                 except Lagged:
                     # expect tokio style index truncation
-                    assert brx._state.subs[brx.key] == len(brx._state.queue) - 1
+                    seq = brx._state.subs[brx.key]
+                    assert seq == len(brx._state.queue) - 1
 
                 # all backpressured entries in the underlying
                 # channel should have been copied into the caster