From c5325abca0a32d5d462d11bc0ccb0d6cc77fd267 Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Wed, 20 Mar 2019 09:13:44 +0000
Subject: [PATCH] add a class-based unit test, found bug in eq function as a
 result: eq function from Example2OpClass was returning a list of assignment
 statements, which was resulting in a list-of-lists being created. flattening
 to a single 1D list was required

---
 src/add/example_buf_pipe.py |  9 +++--
 src/add/test_buf_pipe.py    | 70 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 75 insertions(+), 4 deletions(-)

diff --git a/src/add/example_buf_pipe.py b/src/add/example_buf_pipe.py
index 0574ff35..c399570a 100644
--- a/src/add/example_buf_pipe.py
+++ b/src/add/example_buf_pipe.py
@@ -112,8 +112,8 @@ class NextControl:
 
 def eq(o, i):
     """ makes signals equal: a helper routine which identifies if it is being
-        passsed a list (or tuple) of objects, and calls the objects' eq
-        function.
+        passed a list (or tuple) of objects, or signals, or Records, and calls
+        the objects' eq function.
 
         complex objects (classes) can be used: they must follow the
         convention of having an eq member function, which takes the
@@ -138,7 +138,10 @@ def eq(o, i):
                     rres = eq(ao.fields[field_name], ai[field_name])
                 res += rres
         else:
-            res.append(ao.eq(ai))
+            rres = ao.eq(ai)
+            if not isinstance(rres, Sequence):
+                rres = [rres]
+            res += rres
     return res
 
 
diff --git a/src/add/test_buf_pipe.py b/src/add/test_buf_pipe.py
index 55307cd3..546e6ad7 100644
--- a/src/add/test_buf_pipe.py
+++ b/src/add/test_buf_pipe.py
@@ -5,7 +5,7 @@ from nmigen.cli import verilog, rtlil
 
 from example_buf_pipe import ExampleBufPipe, ExampleBufPipeAdd
 from example_buf_pipe import ExampleCombPipe, CombPipe
-from example_buf_pipe import PrevControl, NextControl
+from example_buf_pipe import PrevControl, NextControl, BufferedPipeline
 from random import randint
 
 
@@ -367,6 +367,68 @@ def test7_resultfn(o_data, expected, i, o):
                 % (i, o, repr(o_data), repr(expected))
 
 
+class Example2OpClass:
+    """ an example of a class used to store 2 operands.
+        requires an eq function, to conform with the pipeline stage API
+    """
+
+    def __init__(self):
+        self.op1 = Signal(16)
+        self.op2 = Signal(16)
+
+    def eq(self, i):
+        return [self.op1.eq(i.op1), self.op2.eq(i.op2)]
+
+
+class ExampleAddClassStage:
+    """ an example of how to use the buffered pipeline, as a class instance
+    """
+
+    def ispec(self):
+        """ returns an instance of an Example2OpClass.
+        """
+        return Example2OpClass()
+
+    def ospec(self):
+        """ returns an output signal which will happen to contain the sum
+            of the two inputs
+        """
+        return Signal(16)
+
+    def process(self, i):
+        """ process the input data (sums the values in the tuple) and returns it
+        """
+        return i.op1 + i.op2
+
+
+class ExampleBufPipeAddClass(BufferedPipeline):
+    """ an example of how to use the buffered pipeline, using a class instance
+    """
+
+    def __init__(self):
+        addstage = ExampleAddClassStage()
+        BufferedPipeline.__init__(self, addstage)
+
+
+class TestInputAdd:
+    def __init__(self, op1, op2):
+        self.op1 = op1
+        self.op2 = op2
+
+
+def test8_resultfn(o_data, expected, i, o):
+    res = expected.op1 + expected.op2
+    assert o_data == res, \
+                "%d-%d data %x not match %s\n" \
+                % (i, o, o_data, repr(expected))
+
+def data_2op():
+        data = []
+        for i in range(num_tests):
+            data.append(TestInputAdd(randint(0, 1<<16-1), randint(0, 1<<16-1)))
+        return data
+
+
 num_tests = 100
 
 if __name__ == '__main__':
@@ -423,3 +485,9 @@ if __name__ == '__main__':
     with open("test_recordcomb_pipe.il", "w") as f:
         f.write(vl)
 
+    print ("test 8")
+    dut = ExampleBufPipeAddClass()
+    data=data_2op()
+    test = Test5(dut, test8_resultfn, data=data)
+    run_simulation(dut, [test.send, test.rcv], vcd_name="test_bufpipe8.vcd")
+
-- 
2.30.2