Add fast fail test using the context api

examples/debugging/fast_error_in_root_after_spawn.py

@@ -0,0 +1,53 @@
+'''
+fast fail test with a context.
+ensure the partially initialized sub-actor process
+doesn't cause a hang on error/cancel of the parent
+nrusery.
+
+'''
+import trio
+import tractor
+
+
+@tractor.context
+async def sleep(
+    ctx: tractor.Context,
+):
+    await trio.sleep(0.5)
+    await ctx.started()
+    await trio.sleep_forever()
+
+
+async def open_ctx(
+    n: tractor._trionics.ActorNursery
+):
+
+    # spawn both actors
+    portal = await n.start_actor(
+        name='sleeper',
+        enable_modules=[__name__],
+    )
+
+    async with portal.open_context(
+        sleep,
+    ) as (ctx, first):
+        assert first is None
+
+
+async def main():
+
+    async with tractor.open_nursery(
+        debug_mode=True,
+        loglevel='runtime',
+    ) as an:
+
+        async with trio.open_nursery() as n:
+            n.start_soon(open_ctx, an)
+
+            await trio.sleep(0.2)
+            await trio.sleep(0.1)
+            assert 0
+
+
+if __name__ == '__main__':
+    trio.run(main)

tests/test_debugger.py

@@ -505,3 +505,21 @@ def test_root_nursery_cancels_before_child_releases_tty_lock(
         assert "tractor._exceptions.RemoteActorError: ('spawner0'" in before
         assert "tractor._exceptions.RemoteActorError: ('name_error'" in before
         assert "NameError: name 'doggypants' is not defined" in before
+
+
+def test_root_cancels_child_context_during_startup(
+    spawn,
+):
+    '''Verify a fast fail in the root doesn't lock up the child reaping
+    and all while using the new context api.
+
+    '''
+    child = spawn('fast_error_in_root_after_spawn')
+
+    child.expect(r"\(Pdb\+\+\)")
+
+    before = str(child.before.decode())
+    assert "AssertionError" in before
+
+    child.sendline('c')
+    child.expect(pexpect.EOF)