Add Fork Choice compliance test generator

tests/core/pyspec/eth2spec/gen_helpers/gen_base/gen_runner.py

@@ -140,17 +140,7 @@ def should_skip_case_dir(case_dir, is_force, diagnostics_obj):
     return is_skip, diagnostics_obj
 
 
-def run_generator(generator_name, test_providers: Iterable[TestProvider]):
-    """
-    Implementation for a general test generator.
-    :param generator_name: The name of the generator. (lowercase snake_case)
-    :param test_providers: A list of test provider,
-            each of these returns a callable that returns an iterable of test cases.
-            The call to get the iterable may set global configuration,
-            and the iterable should not be resumed after a pause with a change of that configuration.
-    :return:
-    """
-
+def create_arg_parser(generator_name: str) -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(
         prog="gen-" + generator_name,
         description=f"Generate YAML test suite files for {generator_name}",
@@ -194,6 +184,23 @@ def run_generator(generator_name, test_providers: Iterable[TestProvider]):
         help="if set only print tests to generate, do not actually run the test and dump the target data",
     )
 
+    return parser
+
+
+def run_generator(generator_name, test_providers: Iterable[TestProvider], parser: argparse.ArgumentParser = None):
+    """
+    Implementation for a general test generator.
+    :param generator_name: The name of the generator. (lowercase snake_case)
+    :param test_providers: A list of test provider,
+            each of these returns a callable that returns an iterable of test cases.
+            The call to get the iterable may set global configuration,
+            and the iterable should not be resumed after a pause with a change of that configuration.
+    :return:
+    """
+
+    if parser is None:
+        parser = create_arg_parser(generator_name)
+
     args = parser.parse_args()
     output_dir = args.output_dir
     if not args.force:

tests/core/pyspec/eth2spec/test/helpers/fork_choice.py

@@ -80,10 +80,13 @@ def run_func():
     yield from with_blob_data(spec, blob_data, run_func)
 
 
-def add_attestation(spec, store, attestation, test_steps, is_from_block=False):
-    spec.on_attestation(store, attestation, is_from_block=is_from_block)
+def add_attestation(spec, store, attestation, test_steps, is_from_block=False, valid=True):
+    run_on_attestation(spec, store, attestation, is_from_block=is_from_block, valid=valid)
     yield get_attestation_file_name(attestation), attestation
-    test_steps.append({'attestation': get_attestation_file_name(attestation)})
+    if valid:
+        test_steps.append({'attestation': get_attestation_file_name(attestation)})
+    else:
+        test_steps.append({'attestation': get_attestation_file_name(attestation), 'valid': False})
 
 
 def add_attestations(spec, store, attestations, test_steps, is_from_block=False):
@@ -282,22 +285,36 @@ def output_head_check(spec, store, test_steps):
     })
 
 
-def output_store_checks(spec, store, test_steps):
-    test_steps.append({
-        'checks': {
-            'time': int(store.time),
-            'head': get_formatted_head_output(spec, store),
-            'justified_checkpoint': {
-                'epoch': int(store.justified_checkpoint.epoch),
-                'root': encode_hex(store.justified_checkpoint.root),
-            },
-            'finalized_checkpoint': {
-                'epoch': int(store.finalized_checkpoint.epoch),
-                'root': encode_hex(store.finalized_checkpoint.root),
-            },
-            'proposer_boost_root': encode_hex(store.proposer_boost_root),
-        }
-    })
+def output_store_checks(spec, store, test_steps, with_viable_for_head_weights=False):
+    checks = {
+        'time': int(store.time),
+        'head': get_formatted_head_output(spec, store),
+        'justified_checkpoint': {
+            'epoch': int(store.justified_checkpoint.epoch),
+            'root': encode_hex(store.justified_checkpoint.root),
+        },
+        'finalized_checkpoint': {
+            'epoch': int(store.finalized_checkpoint.epoch),
+            'root': encode_hex(store.finalized_checkpoint.root),
+        },
+        'proposer_boost_root': encode_hex(store.proposer_boost_root),
+    }
+
+    if with_viable_for_head_weights:
+        filtered_block_roots = spec.get_filtered_block_tree(store).keys()
+        leaves_viable_for_head = [root for root in filtered_block_roots
+                                  if not any(c for c in filtered_block_roots if store.blocks[c].parent_root == root)]
+
+        viable_for_head_roots_and_weights = [
+            {
+                'root': encode_hex(viable_for_head_root),
+                'weight': int(spec.get_weight(store, viable_for_head_root))
+            }
+            for viable_for_head_root in leaves_viable_for_head
+        ]
+        checks['viable_for_head_roots_and_weights'] = viable_for_head_roots_and_weights
+
+    test_steps.append({'checks': checks})
 
 
 def apply_next_epoch_with_attestations(spec,