nimbus-eth2/tests/fuzzing/ssz_fuzzing.nim
Jacek Sieka a7a65bce42
disentangle eth2 types from the ssz library (#2785)
* reorganize ssz dependencies

This PR continues the work in
https://github.com/status-im/nimbus-eth2/pull/2646,
https://github.com/status-im/nimbus-eth2/pull/2779 as well as past
issues with serialization and type, to disentangle SSZ from eth2 and at
the same time simplify imports and exports with a structured approach.

The principal idea here is that when a library wants to introduce SSZ
support, they do so via 3 files:

* `ssz_codecs` which imports and reexports `codecs` - this covers the
basic byte conversions and ensures no overloads get lost
* `xxx_merkleization` imports and exports `merkleization` to specialize
and get access to `hash_tree_root` and friends
* `xxx_ssz_serialization` imports and exports `ssz_serialization` to
specialize ssz for a specific library

Those that need to interact with SSZ always import the `xxx_` versions
of the modules and never `ssz` itself so as to keep imports simple and
safe.

This is similar to how the REST / JSON-RPC serializers are structured in
that someone wanting to serialize spec types to REST-JSON will import
`eth2_rest_serialization` and nothing else.

* split up ssz into a core library that is independendent of eth2 types
* rename `bytes_reader` to `codec` to highlight that it contains coding
and decoding of bytes and native ssz types
* remove tricky List init overload that causes compile issues
* get rid of top-level ssz import
* reenable merkleization tests
* move some "standard" json serializers to spec
* remove `ValidatorIndex` serialization for now
* remove test_ssz_merkleization
* add tests for over/underlong byte sequences
* fix broken seq[byte] test - seq[byte] is not an SSZ type

There are a few things this PR doesn't solve:

* like #2646 this PR is weak on how to handle root and other
dontSerialize fields that "sometimes" should be computed - the same
problem appears in REST / JSON-RPC etc

* Fix a build problem on macOS

* Another way to fix the macOS builds

Co-authored-by: Zahary Karadjov <zahary@gmail.com>
2021-08-18 20:57:58 +02:00

41 lines
1.1 KiB
Nim

import
testutils/fuzzing, faststreams/inputs, serialization/testing/tracing,
../../beacon_chain/spec/datatypes/base
export
ssz, base, fuzzing
template sszFuzzingTest*(T: type) =
test:
block:
let input = unsafeMemoryInput(payload)
let decoded = try: input.readValue(SSZ, T)
except SSZError: break
if input.len.get > 0:
# Some unconsumed input remained, this is not a valid test case
break
let reEncoded = SSZ.encode(decoded)
when T isnot SignedBeaconBlock:
let hash = hash_tree_root(decoded)
if payload != reEncoded:
when hasSerializationTracing:
# Run deserialization again to produce a seriazation trace
# (this is useful for comparing with the initial deserialization)
discard SSZ.decode(reEncoded, T)
echo "Payload with len = ", payload.len
echo payload
echo "Re-encoided payload with len = ", reEncoded.len
echo reEncoded
when T isnot SignedBeaconBlock:
echo "HTR: ", hash
echo repr(decoded)
doAssert false