Refine validate_merge_block unit tests

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

@@ -1,7 +1,5 @@
-from random import Random
 from eth_utils import encode_hex
 from eth2spec.test.exceptions import BlockNotFoundException
-from eth2spec.utils.ssz.ssz_typing import uint256
 from eth2spec.test.helpers.attestations import (
     next_epoch_with_attestations,
     next_slots_with_attestations,
@@ -247,15 +245,6 @@ def apply_next_slots_with_attestations(spec,
     return post_state, store, last_signed_block
 
 
-def prepare_empty_pow_block(spec, rng=Random(3131)):
-    return spec.PowBlock(
-        block_hash=spec.Hash32(spec.hash(bytearray(rng.getrandbits(8) for _ in range(32)))),
-        parent_hash=spec.Hash32(spec.hash(bytearray(rng.getrandbits(8) for _ in range(32)))),
-        total_difficulty=uint256(0),
-        difficulty=uint256(0)
-    )
-
-
 def get_pow_block_file_name(pow_block):
     return f"pow_block_{encode_hex(pow_block.block_hash)}"
 

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

@@ -0,0 +1,20 @@
+from random import Random
+from eth2spec.utils.ssz.ssz_typing import uint256
+
+
+def prepare_empty_pow_block(spec, rng=Random(3131)):
+    return spec.PowBlock(
+        block_hash=spec.Hash32(spec.hash(bytearray(rng.getrandbits(8) for _ in range(32)))),
+        parent_hash=spec.Hash32(spec.hash(bytearray(rng.getrandbits(8) for _ in range(32)))),
+        total_difficulty=uint256(0),
+        difficulty=uint256(0)
+    )
+
+
+def prepare_random_pow_chain(spec, length, rng=Random(3131)):
+    assert length > 0
+    chain = [prepare_empty_pow_block(spec, rng)]
+    for i in range(1, length):
+        chain.append(prepare_empty_pow_block(spec, rng))
+        chain[i].parent_hash = chain[i - 1].block_hash
+    return chain

tests/core/pyspec/eth2spec/test/merge/fork_choice/test_on_merge_block.py

@@ -13,9 +13,11 @@
     state_transition_and_sign_block,
 )
 from eth2spec.test.helpers.fork_choice import (
-    prepare_empty_pow_block,
     add_pow_block,
 )
+from eth2spec.test.helpers.pow_block import (
+    prepare_empty_pow_block,
+)
 from eth2spec.test.helpers.execution_payload import (
     build_state_with_incomplete_transition,
 )

tests/core/pyspec/eth2spec/test/merge/unittests/test_is_valid_terminal_pow_block.py

@@ -0,0 +1,44 @@
+from eth2spec.utils.ssz.ssz_typing import uint256
+from eth2spec.test.helpers.pow_block import (
+    prepare_empty_pow_block,
+)
+from eth2spec.test.context import (
+    spec_state_test,
+    with_merge_and_later,
+)
+
+
+@with_merge_and_later
+@spec_state_test
+def test_is_valid_terminal_pow_block_success_valid(spec, state):
+    parent_block = prepare_empty_pow_block(spec)
+    parent_block.total_difficulty = spec.config.TERMINAL_TOTAL_DIFFICULTY - uint256(1)
+    block = prepare_empty_pow_block(spec)
+    block.parent_hash = parent_block.block_hash
+    block.total_difficulty = spec.config.TERMINAL_TOTAL_DIFFICULTY
+
+    assert spec.is_valid_terminal_pow_block(block, parent_block)
+
+
+@with_merge_and_later
+@spec_state_test
+def test_is_valid_terminal_pow_block_fail_before_terminal(spec, state):
+    parent_block = prepare_empty_pow_block(spec)
+    parent_block.total_difficulty = spec.config.TERMINAL_TOTAL_DIFFICULTY - uint256(2)
+    block = prepare_empty_pow_block(spec)
+    block.parent_hash = parent_block.block_hash
+    block.total_difficulty = spec.config.TERMINAL_TOTAL_DIFFICULTY - uint256(1)
+
+    assert not spec.is_valid_terminal_pow_block(block, parent_block)
+
+
+@with_merge_and_later
+@spec_state_test
+def test_is_valid_terminal_pow_block_fail_just_after_terminal(spec, state):
+    parent_block = prepare_empty_pow_block(spec)
+    parent_block.total_difficulty = spec.config.TERMINAL_TOTAL_DIFFICULTY
+    block = prepare_empty_pow_block(spec)
+    block.parent_hash = parent_block.block_hash
+    block.total_difficulty = spec.config.TERMINAL_TOTAL_DIFFICULTY + uint256(1)
+
+    assert not spec.is_valid_terminal_pow_block(block, parent_block)