test.compat: import tests from Migen as appropriate.

test_signed and test_coding are adjusted slightly to account for
differences in comb propagation between the simulators; we might want
to revert that eventually.

nmigen/compat/sim/__init__.py

@@ -1,7 +1,10 @@
+import functools
+import collections
+import inspect
 from ...back.pysim import *
 
 
-__all__ = ["run_simulation"]
+__all__ = ["run_simulation", "passive"]
 
 
 def run_simulation(fragment_or_module, generators, clocks={"sync": 10}, vcd_name=None,
@@ -19,6 +22,18 @@ def run_simulation(fragment_or_module, generators, clocks={"sync": 10}, vcd_name
     with Simulator(fragment, vcd_file=open(vcd_name, "w") if vcd_name else None) as sim:
         for domain, period in clocks.items():
             sim.add_clock(period / 1e9, domain=domain)
-        for domain, process in generators.items():
-            sim.add_sync_process(process, domain=domain)
+        for domain, processes in generators.items():
+            if isinstance(processes, collections.Iterable) and not inspect.isgenerator(processes):
+                for process in processes:
+                    sim.add_sync_process(process, domain=domain)
+            else:
+                sim.add_sync_process(processes, domain=domain)
         sim.run()
+
+
+def passive(generator):
+    @functools.wraps(generator)
+    def wrapper(*args, **kwargs):
+        yield Passive()
+        yield from generator(*args, **kwargs)
+    return wrapper