Add remote module error handling tests

tests/test_rpc.py

@@ -0,0 +1,80 @@
+"""
+RPC related
+"""
+import pytest
+import tractor
+import trio
+
+
+async def sleep_back_actor(
+    actor_name,
+    func_name,
+    func_defined,
+    exposed_mods,
+):
+    async with tractor.find_actor(actor_name) as portal:
+        try:
+            await portal.run(__name__, func_name)
+        except tractor.RemoteActorError as err:
+            if not func_defined:
+                expect = AttributeError
+            if not exposed_mods:
+                expect = tractor.ModuleNotExposed
+
+            assert err.type is expect
+            raise
+
+
+async def short_sleep():
+    await trio.sleep(0)
+
+
+@pytest.mark.parametrize(
+    'to_call', [
+        ([], 'short_sleep'),
+        ([__name__], 'short_sleep'),
+        ([__name__], 'fake_func'),
+    ],
+    ids=['no_mods', 'this_mod', 'this_mod_bad_func'],
+)
+def test_rpc_errors(arb_addr, to_call):
+    """Test errors when making various RPC requests to an actor
+    that either doesn't have the requested module exposed or doesn't define
+    the named function.
+    """
+    exposed_mods, funcname = to_call
+    func_defined = globals().get(funcname, False)
+
+    async def main():
+        actor = tractor.current_actor()
+        assert actor.is_arbiter
+
+        # spawn a subactor which calls us back
+        async with tractor.open_nursery() as n:
+            await n.run_in_actor(
+                'subactor',
+                sleep_back_actor,
+                actor_name=actor.name,
+                # function from this module the subactor will invoke
+                # when it RPCs back to this actor
+                func_name=funcname,
+                exposed_mods=exposed_mods,
+                func_defined=True if func_defined else False,
+            )
+
+    def run():
+        tractor.run(
+            main,
+            arbiter_addr=arb_addr,
+            rpc_module_paths=exposed_mods,
+        )
+
+    # handle both parameterized cases
+    if exposed_mods and func_defined:
+        run()
+    else:
+        # underlying errors are propogated upwards (yet)
+        with pytest.raises(tractor.RemoteActorError) as err:
+            run()
+
+        assert err.value.type is tractor.RemoteActorError