✨ feat(tests): EIP-7928 No-op and adjacent test case

docs/CHANGELOG.md

@@ -41,6 +41,7 @@ Test fixtures for use by clients are available for each release on the [Github r
 - ✨ Add essential tests for coverage gaps in EIP-7951 (`p256verify` precompile) ([#2179](https://github.com/ethereum/execution-spec-tests/pull/2159), [#2203](https://github.com/ethereum/execution-spec-tests/pull/2203), [#2215](https://github.com/ethereum/execution-spec-tests/pull/2215), [#2216](https://github.com/ethereum/execution-spec-tests/pull/2216), [#2217](https://github.com/ethereum/execution-spec-tests/pull/2217), [#2218](https://github.com/ethereum/execution-spec-tests/pull/2218), [#2221](https://github.com/ethereum/execution-spec-tests/pull/2221), [#2229](https://github.com/ethereum/execution-spec-tests/pull/2229), [#2230](https://github.com/ethereum/execution-spec-tests/pull/2230), [#2237](https://github.com/ethereum/execution-spec-tests/pull/2237), [#2238](https://github.com/ethereum/execution-spec-tests/pull/2238)).
 - ✨ Add EIP-7928 successful and OOG single-opcode tests ([#2118](https://github.com/ethereum/execution-spec-tests/pull/2118)).
 - ✨ Add EIP-7928 tests for EIP-2930 interactions ([#2167](https://github.com/ethereum/execution-spec-tests/pull/2167)).
+- ✨ Add EIP-7928 tests for NOOP operations ([#2178](https://github.com/ethereum/execution-spec-tests/pull/2178)).
 
 ## [v5.0.0](https://github.com/ethereum/execution-spec-tests/releases/tag/v5.0.0) - 2025-09-05
 

src/ethereum_test_types/block_access_list/expectations.py

@@ -5,7 +5,7 @@
 BAL values in tests.
 """
 
-from typing import Any, Callable, Dict, List, Optional
+from typing import Any, Callable, ClassVar, Dict, List, Optional
 
 from pydantic import Field, PrivateAttr
 
@@ -53,6 +53,33 @@ class BalAccountExpectation(CamelModel):
         default=None, description="Explicit absent value expectations using BalAccountAbsentValues"
     )
 
+    _EMPTY: ClassVar[Optional["BalAccountExpectation"]] = None
+
+    @classmethod
+    def empty(cls) -> "BalAccountExpectation":
+        """
+        Create an expectation that validates the account has NO changes.
+
+        This is distinct from `BalAccountExpectation()` with no fields set,
+        which is ambiguous and clashes with `model_fields_set` logic, and
+        will raise a clarifying error if used in expectations.
+
+        Returns:
+            A BalAccountExpectation instance with all change lists empty.
+            This uses a classvar to facilitate identity checks across
+            multiple expectation instances.
+
+        """
+        if cls._EMPTY is None:
+            cls._EMPTY = cls(
+                nonce_changes=[],
+                balance_changes=[],
+                code_changes=[],
+                storage_changes=[],
+                storage_reads=[],
+            )
+        return cls._EMPTY
+
 
 def compose(
     *modifiers: Callable[["BlockAccessList"], "BlockAccessList"],
@@ -168,20 +195,29 @@ def verify_against(self, actual_bal: "BlockAccessList") -> None:
                     raise BlockAccessListValidationError(
                         f"Address {address} should not be in BAL but was found"
                     )
-            elif expectation == BalAccountExpectation():
-                # explicit check for NO account changes for the address
-                if actual_accounts_by_addr.get(address) != BalAccountChange(address=address):
-                    raise BlockAccessListValidationError(
-                        f"No account changes expected for {address} but found "
-                        f"changes: {actual_accounts_by_addr[address]}"
-                    )
+            elif not expectation.model_fields_set:
+                # Disallow ambiguous BalAccountExpectation() with no fields set
+                raise BlockAccessListValidationError(
+                    f"Address {address}: BalAccountExpectation() with no fields set is "
+                    f"ambiguous. Use BalAccountExpectation.empty() to validate no changes, "
+                    f"or explicitly set the fields to validate "
+                    f"(e.g., nonce_changes=[...])."
+                )
             else:
                 # check address is present and validate changes
                 if address not in actual_accounts_by_addr:
                     raise BlockAccessListValidationError(
                         f"Expected address {address} not found in actual BAL"
                     )
 
+                if expectation is BalAccountExpectation.empty():
+                    # explicit check for "no changes" validation w/ .empty()
+                    if actual_accounts_by_addr.get(address) != BalAccountChange(address=address):
+                        raise BlockAccessListValidationError(
+                            f"No account changes expected for {address} but found "
+                            f"changes: {actual_accounts_by_addr[address]}"
+                        )
+
                 actual_account = actual_accounts_by_addr[address]
                 try:
                     self._compare_account_expectations(expectation, actual_account)

src/ethereum_test_types/tests/test_block_access_lists.py

@@ -69,7 +69,18 @@ def test_address_exclusion_validation_raises_when_address_is_present():
         expectation.verify_against(actual_bal)
 
 
-def test_empty_account_changes_raises_when_changes_are_present():
+@pytest.mark.parametrize(
+    "empty_changes_definition,exception_message",
+    [
+        [BalAccountExpectation(), "ambiguous. Use BalAccountExpectation.empty()"],
+        [BalAccountExpectation.empty(), "No account changes expected for "],
+    ],
+    ids=["BalAccountExpectation()", "BalAccountExpectation.empty()"],
+)
+def test_empty_account_changes_definitions(
+    empty_changes_definition,
+    exception_message,
+):
     """
     Test that validation fails when expected empty changes but actual
     has changes.
@@ -85,12 +96,11 @@ def test_empty_account_changes_raises_when_changes_are_present():
         ]
     )
 
-    expectation = BlockAccessListExpectation(account_expectations={alice: BalAccountExpectation()})
+    expectation = BlockAccessListExpectation(
+        account_expectations={alice: empty_changes_definition}
+    )
 
-    with pytest.raises(
-        BlockAccessListValidationError,
-        match=f"No account changes expected for {alice}",
-    ):
+    with pytest.raises(BlockAccessListValidationError, match=exception_message):
         expectation.verify_against(actual_bal)