67b957d4f4
Compared to tests in the repository root, tests in the package have
many downsides:
* Unless explicitly excluded in find_packages(), tests and their
support code effectively become a part of public API.
This, unfortunately, happened with FHDLTestCase, which was never
intended for downstream use.
* Even if explicitly excluded from the setuptools package, using
an editable install, or setting PYTHONPATH still allows accessing
the tests.
* Having a sub-package that is present in the source tree but not
exported (or, worse, exported only sometimes) is confusing.
* The name `nmigen.test` cannot be used for anything else, such as
testing utilities that *are* intended for downstream use.
128 lines
3.6 KiB
Python
128 lines
3.6 KiB
Python
from nmigen.hdl import *
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from nmigen.asserts import *
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from nmigen.back.pysim import *
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from nmigen.lib.coding import *
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from .utils import *
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class EncoderTestCase(FHDLTestCase):
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def test_basic(self):
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enc = Encoder(4)
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def process():
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self.assertEqual((yield enc.n), 1)
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self.assertEqual((yield enc.o), 0)
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yield enc.i.eq(0b0001)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 0)
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yield enc.i.eq(0b0100)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 2)
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yield enc.i.eq(0b0110)
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yield Settle()
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self.assertEqual((yield enc.n), 1)
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self.assertEqual((yield enc.o), 0)
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sim = Simulator(enc)
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sim.add_process(process)
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sim.run()
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class PriorityEncoderTestCase(FHDLTestCase):
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def test_basic(self):
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enc = PriorityEncoder(4)
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def process():
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self.assertEqual((yield enc.n), 1)
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self.assertEqual((yield enc.o), 0)
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yield enc.i.eq(0b0001)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 0)
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yield enc.i.eq(0b0100)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 2)
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yield enc.i.eq(0b0110)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 1)
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sim = Simulator(enc)
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sim.add_process(process)
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sim.run()
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class DecoderTestCase(FHDLTestCase):
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def test_basic(self):
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dec = Decoder(4)
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def process():
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self.assertEqual((yield dec.o), 0b0001)
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yield dec.i.eq(1)
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yield Settle()
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self.assertEqual((yield dec.o), 0b0010)
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yield dec.i.eq(3)
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yield Settle()
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self.assertEqual((yield dec.o), 0b1000)
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yield dec.n.eq(1)
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yield Settle()
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self.assertEqual((yield dec.o), 0b0000)
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sim = Simulator(dec)
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sim.add_process(process)
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sim.run()
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class ReversibleSpec(Elaboratable):
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def __init__(self, encoder_cls, decoder_cls, args):
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self.encoder_cls = encoder_cls
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self.decoder_cls = decoder_cls
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self.coder_args = args
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def elaborate(self, platform):
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m = Module()
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enc, dec = self.encoder_cls(*self.coder_args), self.decoder_cls(*self.coder_args)
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m.submodules += enc, dec
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m.d.comb += [
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dec.i.eq(enc.o),
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Assert(enc.i == dec.o)
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]
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return m
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class HammingDistanceSpec(Elaboratable):
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def __init__(self, distance, encoder_cls, args):
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self.distance = distance
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self.encoder_cls = encoder_cls
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self.coder_args = args
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def elaborate(self, platform):
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m = Module()
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enc1, enc2 = self.encoder_cls(*self.coder_args), self.encoder_cls(*self.coder_args)
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m.submodules += enc1, enc2
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m.d.comb += [
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Assume(enc1.i + 1 == enc2.i),
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Assert(sum(enc1.o ^ enc2.o) == self.distance)
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]
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return m
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class GrayCoderTestCase(FHDLTestCase):
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def test_reversible(self):
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spec = ReversibleSpec(encoder_cls=GrayEncoder, decoder_cls=GrayDecoder, args=(16,))
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self.assertFormal(spec, mode="prove")
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def test_distance(self):
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spec = HammingDistanceSpec(distance=1, encoder_cls=GrayEncoder, args=(16,))
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self.assertFormal(spec, mode="prove")
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