gossip: add GossipDecodeHarness for v2 conformance testing

src/test_suite/fixture_utils.py

@@ -166,16 +166,15 @@ def write_fixture_to_disk(
         fixture.ParseFromString(serialized_fixture)
 
         # Encode fields for instruction context and effects
-        context = harness_ctx.context_type()
-        context.CopyFrom(fixture.input)
-        # encode_input(context)
-        harness_ctx.context_human_encode_fn(context)
+        if harness_ctx.context_type is not None:
+            context = harness_ctx.context_type()
+            context.CopyFrom(fixture.input)
+            harness_ctx.context_human_encode_fn(context)
+            fixture.input.CopyFrom(context)
 
         instr_effects = harness_ctx.effects_type()
         instr_effects.CopyFrom(fixture.output)
         harness_ctx.effects_human_encode_fn(instr_effects)
-
-        fixture.input.CopyFrom(context)
         fixture.output.CopyFrom(instr_effects)
 
         with open(output_dir / (file_stem + ".fix.txt"), "w") as f:
@@ -367,6 +366,9 @@ def regenerate_fixture(test_file: Path) -> int:
     fixture = read_fixture(test_file)
     harness_ctx = get_harness_for_entrypoint(fixture.metadata.fn_entrypoint)
 
+    if harness_ctx.context_type is None:
+        return  # Scalar-input harnesses do not support feature regeneration
+
     features_path = pb_utils.find_field_with_type(
         harness_ctx.context_type.DESCRIPTOR, context_pb.FeatureSet.DESCRIPTOR
     )

src/test_suite/fuzz_context.py

@@ -9,7 +9,7 @@
 import test_suite.protos.invoke_pb2 as invoke_pb
 import test_suite.protos.vm_pb2 as vm_pb
 import test_suite.protos.block_pb2 as block_pb
-import test_suite.protos.pack_pb2 as pack_pb
+
 import test_suite.protos.gossip_pb2 as gossip_pb
 
 import test_suite.block.codec_utils as block_codec
@@ -75,12 +75,6 @@
     consensus_diff_effect_fn=txn_diff.consensus_txn_diff_effects,
 )
 
-PackComputeBudgetHarness = HarnessCtx(
-    fuzz_fn_name="sol_compat_pack_compute_budget_v1",
-    fixture_desc=pack_pb.PackComputeBudgetFixture.DESCRIPTOR,
-    context_extension=".packctx",
-)
-
 BlockHarness = HarnessCtx(
     fuzz_fn_name="sol_compat_block_execute_v1",
     fixture_desc=block_pb.BlockFixture.DESCRIPTOR,
@@ -100,6 +94,13 @@
     effects_human_encode_fn=gossip_codec.encode_output,
 )
 
+GossipDecodeHarness = HarnessCtx(
+    fuzz_fn_name="sol_compat_gossip_decode_v1",
+    fixture_desc=gossip_pb.GossipFixture.DESCRIPTOR,
+    context_extension=".gossipdecodectx",
+    effects_human_encode_fn=gossip_codec.encode_effects,
+)
+
 
 ENTRYPOINT_HARNESS_MAP = {
     obj.fuzz_fn_name: obj for obj in globals().values() if isinstance(obj, HarnessCtx)

src/test_suite/fuzz_interface.py

@@ -90,9 +90,14 @@ class HarnessCtx:
 
     def __post_init__(self, fixture_desc):
         self.fixture_type = message_factory.GetMessageClass(fixture_desc)
-        self.context_type = message_factory.GetMessageClass(
-            fixture_desc.fields_by_name["input"].message_type
-        )
+        input_field = fixture_desc.fields_by_name["input"]
+        if input_field.message_type is not None:
+            self.context_type = message_factory.GetMessageClass(
+                input_field.message_type
+            )
+        else:
+            # Scalar input (e.g. bytes) - no message class to derive
+            self.context_type = None
         self.effects_type = message_factory.GetMessageClass(
             fixture_desc.fields_by_name["output"].message_type
         )

src/test_suite/gossip/codec_utils.py

@@ -38,3 +38,8 @@ def decode_input(msg: gossip_pb.GossipMessageBinary):
 def encode_output(effects: gossip_pb.AcceptsGossipMessage):
     """No-op: output is just a bool, already human-readable."""
     pass
+
+
+def encode_effects(effects: gossip_pb.GossipEffects):
+    """No-op: GossipEffects fields are already human-readable."""
+    pass

src/test_suite/multiprocessing_utils.py

@@ -318,6 +318,9 @@ def read_context(harness_ctx: HarnessCtx, test_file: Path) -> message.Message |
     Returns:
         - message.Message | None: Instruction context, or None if reading failed.
     """
+    if harness_ctx.context_type is None:
+        return None
+
     # Try to read in first as binary-encoded Protobuf messages
     try:
         # Read in binary Protobuf messages
@@ -440,8 +443,10 @@ def decode_single_test_case(test_file: Path) -> int:
     # Encode the input fields to be human readable
     if test_file.suffix == FIXTURE_EXTENSION:
         output = harness_ctx.fixture_type()
-    else:
+    elif harness_ctx.context_type is not None:
         output = harness_ctx.context_type()
+    else:
+        return 0
 
     output.ParseFromString(serialized_protobuf)