def test_provider_index_round_trip(mock_packages):
p = ProviderIndex(spack.repo.all_package_names())
ostream = StringIO()
p.to_json(ostream)
istream = StringIO(ostream.getvalue())
q = ProviderIndex.from_json(istream)
assert p == q
def read(self, stream):
self.index = ProviderIndex.from_json(stream)