Implement eth.abc module with abstract base classes for public APIs

Author: pipermerriam

eth/_utils/datatypes.py

@@ -11,6 +11,8 @@
 
 from typing import Any, Dict, Tuple, Type, TypeVar, Iterator, List
 
+from eth.abc import ConfigurableAPI
+
 
 def _is_local_prop(prop: str) -> bool:
     return len(prop.split('.')) == 1
@@ -64,7 +66,7 @@ def _get_top_level_keys(overrides: Dict[str, Any]) -> Iterator[str]:
 T = TypeVar('T')
 
 
-class Configurable(object):
+class Configurable(ConfigurableAPI):
     """
     Base class for simple inline subclassing
     """

eth/_utils/db.py

@@ -1,40 +1,32 @@
-from typing import (
-    TYPE_CHECKING,
-)
-
 from eth_typing import (
     Hash32,
 )
 
-from eth.rlp.headers import (
-    BlockHeader,
+from eth.abc import (
+    BlockHeaderAPI,
+    ChainDatabaseAPI,
+    StateAPI,
 )
 from eth.typing import (
     AccountState,
 )
-from eth.vm.state import (
-    BaseState,
-)
-
-if TYPE_CHECKING:
-    from eth.db.chain import BaseChainDB  # noqa: F401
 
 
-def get_parent_header(block_header: BlockHeader, db: 'BaseChainDB') -> BlockHeader:
+def get_parent_header(block_header: BlockHeaderAPI, db: ChainDatabaseAPI) -> BlockHeaderAPI:
     """
     Returns the header for the parent block.
     """
     return db.get_block_header_by_hash(block_header.parent_hash)
 
 
-def get_block_header_by_hash(block_hash: Hash32, db: 'BaseChainDB') -> BlockHeader:
+def get_block_header_by_hash(block_hash: Hash32, db: ChainDatabaseAPI) -> BlockHeaderAPI:
     """
     Returns the header for the parent block.
     """
     return db.get_block_header_by_hash(block_hash)
 
 
-def apply_state_dict(state: BaseState, state_dict: AccountState) -> None:
+def apply_state_dict(state: StateAPI, state_dict: AccountState) -> None:
     for account, account_data in state_dict.items():
         state.set_balance(account, account_data["balance"])
         state.set_nonce(account, account_data["nonce"])

eth/_utils/spoof.py

@@ -14,9 +14,9 @@
     DEFAULT_SPOOF_S,
 )
 
-from eth.rlp.transactions import (
-    BaseTransaction,
-    BaseUnsignedTransaction,
+from eth.abc import (
+    SignedTransactionAPI,
+    UnsignedTransactionAPI,
 )
 
 SPOOF_ATTRIBUTES_DEFAULTS = {
@@ -31,7 +31,7 @@
 class SpoofAttributes:
     def __init__(
             self,
-            spoof_target: Union[BaseTransaction, BaseUnsignedTransaction],
+            spoof_target: Union[SignedTransactionAPI, UnsignedTransactionAPI],
             **overrides: Any) -> None:
         self.spoof_target = spoof_target
         self.overrides = overrides