refactor(fixtures): Remove formats.py, embed properties as class va…

…rs (#826)

* refactor(fixtures): Embed FixtureFormat methods in instance

* refactor(fw): remove `src/ethereum_test_fixtures/formats.py`

* refactor(fw): rename

* fix(fw): nit

* fix(fw): pydantic fixture format

* fix(fixtures): remove unused properties

* fix(fixtures): remove unused properties

* fix(fixtures): remove unused properties

* fix(specs): tox

src/cli/gen_index.py

@@ -20,7 +20,7 @@
 )
 
 from ethereum_test_base_types import HexNumber
-from ethereum_test_fixtures import FixtureFormats
+from ethereum_test_fixtures import FIXTURE_FORMATS, BlockchainFixture, FixtureFormat
 from ethereum_test_fixtures.consume import IndexFile, TestCaseIndexFile
 from ethereum_test_fixtures.file import Fixtures
 
@@ -48,21 +48,16 @@ def count_json_files_exclude_index(start_path: Path) -> int:
     return json_file_count
 
 
-def infer_fixture_format_from_path(file: Path) -> FixtureFormats:
+def infer_fixture_format_from_path(file: Path) -> FixtureFormat | None:
     """
     Attempt to infer the fixture format from the file path.
     """
-    if "blockchain_tests_engine" in file.parts:
-        return FixtureFormats.BLOCKCHAIN_TEST_ENGINE
-    if "blockchain_tests" in file.parts:
-        return FixtureFormats.BLOCKCHAIN_TEST
+    for fixture_type in FIXTURE_FORMATS.values():
+        if fixture_type.output_base_dir_name() in file.parts:
+            return fixture_type
     if "BlockchainTests" in file.parts:  # ethereum/tests
-        return FixtureFormats.BLOCKCHAIN_TEST
-    if "state_tests" in file.parts:
-        return FixtureFormats.STATE_TEST
-    if "eof_tests" in file.parts:
-        return FixtureFormats.EOF_TEST
-    return FixtureFormats.UNSET_TEST_FORMAT
+        return BlockchainFixture
+    return None
 
 
 @click.command(
@@ -200,7 +195,7 @@ def generate_fixtures_index(
                         json_path=relative_file_path,
                         fixture_hash=fixture.info.get("hash", None),
                         fork=fixture.get_fork(),
-                        format=fixture.format,
+                        format=fixture.__class__,
                     )
                 )
 

src/ethereum_test_fixtures/__init__.py

@@ -2,33 +2,35 @@
 Ethereum test fixture format definitions.
 """
 
-from typing import List, Type
+from typing import Dict
 
-from .base import BaseFixture
+from .base import BaseFixture, FixtureFormat
 from .blockchain import EngineFixture as BlockchainEngineFixture
 from .blockchain import Fixture as BlockchainFixture
 from .blockchain import FixtureCommon as BlockchainFixtureCommon
 from .collector import FixtureCollector, TestInfo
 from .eof import Fixture as EOFFixture
-from .formats import FixtureFormats
 from .state import Fixture as StateFixture
 from .verify import FixtureVerifier
 
-FIXTURE_TYPES: List[Type[BaseFixture]] = [
-    BlockchainFixture,
-    BlockchainEngineFixture,
-    EOFFixture,
-    StateFixture,
-]
+FIXTURE_FORMATS: Dict[str, FixtureFormat] = {
+    f.fixture_format_name: f  # type: ignore
+    for f in [
+        BlockchainFixture,
+        BlockchainEngineFixture,
+        EOFFixture,
+        StateFixture,
+    ]
+}
 __all__ = [
-    "FIXTURE_TYPES",
+    "FIXTURE_FORMATS",
     "BaseFixture",
     "BlockchainFixture",
     "BlockchainFixtureCommon",
     "BlockchainEngineFixture",
     "EOFFixture",
     "FixtureCollector",
-    "FixtureFormats",
+    "FixtureFormat",
     "FixtureVerifier",
     "StateFixture",
     "TestInfo",

src/ethereum_test_fixtures/base.py

@@ -5,20 +5,30 @@
 import hashlib
 import json
 from functools import cached_property
-from typing import Any, ClassVar, Dict
+from typing import Any, ClassVar, Dict, Type
 
 from pydantic import Field
 
 from ethereum_test_base_types import CamelModel, ReferenceSpec
-
-from .formats import FixtureFormats
+from ethereum_test_forks import Fork
 
 
 class BaseFixture(CamelModel):
     """Represents a base Ethereum test fixture of any type."""
 
     info: Dict[str, str] = Field(default_factory=dict, alias="_info")
-    format: ClassVar[FixtureFormats] = FixtureFormats.UNSET_TEST_FORMAT
+
+    # Fixture format properties
+    fixture_format_name: ClassVar[str] = "unset"
+    output_file_extension: ClassVar[str] = ".json"
+    description: ClassVar[str] = "Unknown fixture format; it has not been set."
+
+    @classmethod
+    def output_base_dir_name(cls) -> str:
+        """
+        Returns the name of the subdirectory where this type of fixture should be dumped to.
+        """
+        return cls.fixture_format_name.replace("test", "tests")
 
     @cached_property
     def json_dict(self) -> Dict[str, Any]:
@@ -69,3 +79,16 @@ def get_fork(self) -> str | None:
         Returns the fork of the fixture as a string.
         """
         raise NotImplementedError
+
+    @classmethod
+    def supports_fork(cls, fork: Fork) -> bool:
+        """
+        Returns whether the fixture can be generated for the given fork.
+
+        By default, all fixtures support all forks.
+        """
+        return True
+
+
+# Type alias for a base fixture class
+FixtureFormat = Type[BaseFixture]

src/ethereum_test_fixtures/blockchain.py

@@ -23,7 +23,7 @@
     ZeroPaddedHexNumber,
 )
 from ethereum_test_exceptions import EngineAPIError, ExceptionInstanceOrList
-from ethereum_test_forks import Fork
+from ethereum_test_forks import Fork, Paris
 from ethereum_test_types.types import (
     AuthorizationTupleGeneric,
     ConsolidationRequest,
@@ -41,7 +41,6 @@
 )
 
 from .base import BaseFixture
-from .formats import FixtureFormats
 
 
 class HeaderForkRequirement(str):
@@ -499,19 +498,32 @@ class Fixture(FixtureCommon):
     Cross-client specific blockchain test model use in JSON fixtures.
     """
 
+    fixture_format_name: ClassVar[str] = "blockchain_test"
+    description: ClassVar[str] = "Tests that generate a blockchain test fixture."
+
     genesis_rlp: Bytes = Field(..., alias="genesisRLP")
     blocks: List[FixtureBlock | InvalidFixtureBlock]
     seal_engine: Literal["NoProof"] = Field("NoProof")
 
-    format: ClassVar[FixtureFormats] = FixtureFormats.BLOCKCHAIN_TEST
-
 
 class EngineFixture(FixtureCommon):
     """
     Engine specific test fixture information.
     """
 
+    fixture_format_name: ClassVar[str] = "blockchain_test_engine"
+    description: ClassVar[
+        str
+    ] = "Tests that generate a blockchain test fixture in Engine API format."
+
     payloads: List[FixtureEngineNewPayload] = Field(..., alias="engineNewPayloads")
     sync_payload: FixtureEngineNewPayload | None = None
 
-    format: ClassVar[FixtureFormats] = FixtureFormats.BLOCKCHAIN_TEST_ENGINE
+    @classmethod
+    def supports_fork(cls, fork: Fork) -> bool:
+        """
+        Returns whether the fixture can be generated for the given fork.
+
+        The Engine API is available only on Paris and afterwards.
+        """
+        return fork >= Paris

src/ethereum_test_fixtures/collector.py

@@ -15,7 +15,6 @@
 
 from .base import BaseFixture
 from .file import Fixtures
-from .formats import FixtureFormats
 from .verify import FixtureVerifier
 
 
@@ -139,8 +138,8 @@ def add_fixture(self, info: TestInfo, fixture: BaseFixture) -> Path:
 
         fixture_path = (
             self.output_dir
-            / fixture.format.output_base_dir_name
-            / fixture_basename.with_suffix(fixture.format.output_file_extension)
+            / fixture.output_base_dir_name()
+            / fixture_basename.with_suffix(fixture.output_file_extension)
         )
         if fixture_path not in self.all_fixtures.keys():  # relevant when we group by test function
             self.all_fixtures[fixture_path] = Fixtures(root={})
@@ -163,7 +162,7 @@ def dump_fixtures(self) -> None:
         os.makedirs(self.output_dir, exist_ok=True)
         for fixture_path, fixtures in self.all_fixtures.items():
             os.makedirs(fixture_path.parent, exist_ok=True)
-            if len({fixture.format for fixture in fixtures.values()}) != 1:
+            if len({fixture.__class__ for fixture in fixtures.values()}) != 1:
                 raise TypeError("All fixtures in a single file must have the same format.")
             fixtures.collect_into_file(fixture_path)
 
@@ -173,11 +172,11 @@ def verify_fixture_files(self, evm_fixture_verification: FixtureVerifier) -> Non
         """
         for fixture_path, name_fixture_dict in self.all_fixtures.items():
             for fixture_name, fixture in name_fixture_dict.items():
-                if FixtureFormats.is_verifiable(fixture.format):
+                if evm_fixture_verification.is_verifiable(fixture.__class__):
                     info = self.json_path_to_test_item[fixture_path]
                     verify_fixtures_dump_dir = self._get_verify_fixtures_dump_dir(info)
                     evm_fixture_verification.verify_fixture(
-                        fixture.format,
+                        fixture.__class__,
                         fixture_path,
                         fixture_name=None,
                         debug_output_path=verify_fixtures_dump_dir,

src/ethereum_test_fixtures/consume.py

@@ -5,15 +5,16 @@
 import datetime
 import json
 from pathlib import Path
-from typing import List, TextIO
+from typing import Annotated, List, TextIO
 
-from pydantic import BaseModel, RootModel
+from pydantic import BaseModel, PlainSerializer, PlainValidator, RootModel
 
 from ethereum_test_base_types import HexNumber
+from ethereum_test_fixtures import FIXTURE_FORMATS, FixtureFormat
 
+from .blockchain import EngineFixture as BlockchainEngineFixture
 from .blockchain import Fixture as BlockchainFixture
 from .file import Fixtures
-from .formats import FixtureFormats
 from .state import Fixture as StateFixture
 
 
@@ -25,7 +26,11 @@ class TestCaseBase(BaseModel):
     id: str
     fixture_hash: HexNumber | None
     fork: str | None
-    format: FixtureFormats
+    format: Annotated[
+        FixtureFormat,
+        PlainSerializer(lambda f: f.fixture_format_name),
+        PlainValidator(lambda f: FIXTURE_FORMATS[f] if f in FIXTURE_FORMATS else f),
+    ]
     __test__ = False  # stop pytest from collecting this class as a test
 
 
@@ -129,14 +134,14 @@ def from_stream(cls, fd: TextIO) -> "TestCases":
         fixtures = Fixtures.from_json_data(json.load(fd))
         test_cases = []
         for fixture_name, fixture in fixtures.items():
-            if fixture.format == FixtureFormats.BLOCKCHAIN_TEST_ENGINE:
+            if fixture == BlockchainEngineFixture:
                 print("Skipping engine fixture", fixture_name)
             test_cases.append(
                 TestCaseStream(
                     id=fixture_name,
                     fixture_hash=fixture.hash,
                     fork=fixture.get_fork(),
-                    format=fixture.format,
+                    format=fixture.__class__,
                     fixture=fixture,
                 )
             )

src/ethereum_test_fixtures/eof.py

@@ -12,7 +12,6 @@
 from ethereum_test_types.eof.v1 import ContainerKind
 
 from .base import BaseFixture
-from .formats import FixtureFormats
 
 
 class Result(CamelModel):
@@ -50,9 +49,10 @@ class Fixture(BaseFixture):
     Fixture for a single EOFTest.
     """
 
-    vectors: Mapping[Number, Vector]
+    fixture_format_name: ClassVar[str] = "eof_test"
+    description: ClassVar[str] = "Tests that generate an EOF test fixture."
 
-    format: ClassVar[FixtureFormats] = FixtureFormats.EOF_TEST
+    vectors: Mapping[Number, Vector]
 
     def get_fork(self) -> str | None:
         """

src/ethereum_test_fixtures/file.py

@@ -3,20 +3,16 @@
 """
 import json
 from pathlib import Path
-from typing import Any, Dict, Literal, Optional
+from typing import Any, Dict, Optional
 
 from pydantic import RootModel
 
+from .base import FixtureFormat
 from .blockchain import EngineFixture as BlockchainEngineFixture
 from .blockchain import Fixture as BlockchainFixture
 from .eof import Fixture as EOFFixture
-from .formats import FixtureFormats
 from .state import Fixture as StateFixture
 
-FixtureFormatsValues = Literal[
-    "blockchain_test_engine", "blockchain_test", "state_test", "eof_test", "unset_test_format"
-]
-
 FixtureModel = BlockchainFixture | BlockchainEngineFixture | StateFixture | EOFFixture
 
 
@@ -75,7 +71,7 @@ def collect_into_file(self, file_path: Path):
     def from_file(
         cls,
         file_path: Path,
-        fixture_format: Optional[FixtureFormats | FixtureFormatsValues] = None,
+        fixture_format: Optional[FixtureFormat] = None,
     ) -> "BaseFixturesRootModel":
         """
         Dynamically create a fixture model from the specified json file and,
@@ -89,7 +85,7 @@ def from_file(
     def from_json_data(
         cls,
         json_data: Dict[str, Any],
-        fixture_format: Optional[FixtureFormats | FixtureFormatsValues] = None,
+        fixture_format: Optional[FixtureFormat] = None,
     ) -> "BaseFixturesRootModel":
         """
         Dynamically create a fixture model from the specified json data and,
@@ -101,17 +97,13 @@ def from_json_data(
         fixture_format will provide a speed-up.
         """
         model_mapping = {
-            FixtureFormats.BLOCKCHAIN_TEST: BlockchainFixtures,
-            FixtureFormats.BLOCKCHAIN_TEST_ENGINE: BlockchainEngineFixtures,
-            FixtureFormats.STATE_TEST: StateFixtures,
-            FixtureFormats.EOF_TEST: EOFFixtures,
-            FixtureFormats.BLOCKCHAIN_TEST.value: BlockchainFixtures,
-            FixtureFormats.BLOCKCHAIN_TEST_ENGINE.value: BlockchainEngineFixtures,
-            FixtureFormats.STATE_TEST.value: StateFixtures,
-            FixtureFormats.EOF_TEST.value: EOFFixtures,
+            BlockchainFixture: BlockchainFixtures,
+            BlockchainEngineFixture: BlockchainEngineFixtures,
+            StateFixture: StateFixtures,
+            EOFFixture: EOFFixtures,
         }
 
-        if fixture_format not in [None, "unset_test_format", FixtureFormats.UNSET_TEST_FORMAT]:
+        if fixture_format is not None:
             if fixture_format not in model_mapping:
                 raise TypeError(f"Unsupported fixture format: {fixture_format}")
             model_class = model_mapping[fixture_format]