Use assert_type to check for type inference failures for actor endpoints

Pull Request resolved: #515

This requires running pyright on the file in the oss test because pyre doesn't seem to care about the assert_type statement.
ghstack-source-id: 295765471

Differential Revision: [D78185660](https://our.internmc.facebook.com/intern/diff/D78185660/)

Author: zdevito

.github/workflows/test-cuda.yml

@@ -47,6 +47,10 @@ jobs:
         # Install the built wheel from artifact
         install_wheel_from_artifact
 
+        # tests the type_assert statements in test_python_actor are correct
+        # pyre currently does not check these assertions
+        pyright python/tests/test_python_actors.py
+
         # Run CUDA tests
         LC_ALL=C pytest python/tests/ -s -v -m "not oss_skip"
         python python/tests/test_mock_cuda.py

python/tests/requirements.txt

@@ -2,3 +2,4 @@ pytest
 pytest-timeout
 pytest-asyncio
 pytest-xdist
+pyright

python/tests/test_python_actors.py

@@ -27,6 +27,8 @@
     proc_mesh,
 )
 from monarch.rdma import RDMABuffer
+from typing_extensions import assert_type
+
 
 needs_cuda = pytest.mark.skipif(
     not torch.cuda.is_available(),
@@ -46,6 +48,10 @@ async def incr(self):
     async def value(self) -> int:
         return self.v
 
+    @endpoint
+    def value_sync_endpoint(self) -> int:
+        return self.v
+
 
 class Indirect(Actor):
     @endpoint
@@ -79,10 +85,17 @@ async def test_choose():
     i = await proc.spawn("indirect", Indirect)
     v.incr.broadcast()
     result = await v.value.choose()
+
+    # Test that Pyre derives the correct type for result (int, not Any)
+    assert_type(result, int)
     result2 = await i.call_value.choose(v)
 
     assert result == result2
 
+    result3 = await v.value_sync_endpoint.choose()
+    assert_type(result, int)
+    assert result2 == result3
+
 
 async def test_stream():
     proc = await local_proc_mesh(gpus=2)
@@ -551,12 +564,12 @@ async def nope():
 
     assert v == 5
 
-    def nope():
+    def nope2():
         nonlocal v
         v += 1
         raise ValueError("nope")
 
-    f = Future(incr, nope)
+    f = Future(incr, nope2)
 
     with pytest.raises(ValueError):
         f.get()