Improve Ogmios backend module

.github/workflows/main.yml

@@ -32,16 +32,16 @@ jobs:
       - name: Install dependencies
         run: |
           poetry install
-      - name: Run static analyses
-        run: |
-          make qa
       - name: Run unit tests
         run: |
           poetry run pytest --doctest-modules --ignore=examples --cov=pycardano --cov-config=.coveragerc --cov-report=xml
       - name: "Upload coverage to Codecov"
         uses: codecov/codecov-action@v3
         with:
           fail_ci_if_error: true
+      - name: Run static analyses
+        run: |
+          make qa
 
   continuous-integration:
     runs-on: ${{ matrix.os }}

pycardano/address.py

@@ -9,7 +9,7 @@
 from __future__ import annotations
 
 from enum import Enum
-from typing import Union
+from typing import Union, Type
 
 from pycardano.crypto.bech32 import decode, encode
 from pycardano.exception import (
@@ -160,7 +160,7 @@ def to_primitive(self) -> bytes:
         return self.encode()
 
     @classmethod
-    def from_primitive(cls, value: bytes) -> PointerAddress:
+    def from_primitive(cls: Type[PointerAddress], value: bytes) -> PointerAddress:
         return cls.decode(value)
 
     def __eq__(self, other):
@@ -339,7 +339,7 @@ def to_primitive(self) -> bytes:
         return bytes(self)
 
     @classmethod
-    def from_primitive(cls, value: Union[bytes, str]) -> Address:
+    def from_primitive(cls: Type[Address], value: Union[bytes, str]) -> Address:
         if isinstance(value, str):
             value = bytes(decode(value))
         header = value[0]

pycardano/backend/ogmios.py

@@ -1,7 +1,8 @@
 import calendar
 import json
 import time
-from typing import Dict, List, Union
+from enum import Enum
+from typing import Any, Dict, List, Optional, Union, Tuple
 
 import cbor2
 import requests
@@ -32,7 +33,24 @@
 __all__ = ["OgmiosChainContext"]
 
 
+JSON = Dict[str, Any]
+
+
+class OgmiosQueryType(str, Enum):
+    Query = "Query"
+    SubmitTx = "SubmitTx"
+    EvaluateTx = "EvaluateTx"
+
+
 class OgmiosChainContext(ChainContext):
+    _ws_url: str
+    _network: Network
+    _service_name: str
+    _kupo_url: Optional[str]
+    _last_known_block_slot: int
+    _genesis_param: Optional[GenesisParameters]
+    _protocol_param: Optional[ProtocolParameters]
+
     def __init__(
         self,
         ws_url: str,
@@ -48,15 +66,15 @@ def __init__(
         self._genesis_param = None
         self._protocol_param = None
 
-    def _request(self, method: str, args: dict) -> Union[dict, int]:
+    def _request(self, method: OgmiosQueryType, args: JSON) -> Any:
         ws = websocket.WebSocket()
         ws.connect(self._ws_url)
         request = json.dumps(
             {
                 "type": "jsonwsp/request",
                 "version": "1.0",
                 "servicename": self._service_name,
-                "methodname": method,
+                "methodname": method.value,
                 "args": args,
             },
             separators=(",", ":"),
@@ -86,10 +104,9 @@ def _fraction_parser(fraction: str) -> float:
     @property
     def protocol_param(self) -> ProtocolParameters:
         """Get current protocol parameters"""
-        method = "Query"
         args = {"query": "currentProtocolParameters"}
         if not self._protocol_param or self._check_chain_tip_and_update():
-            result = self._request(method, args)
+            result = self._request(OgmiosQueryType.Query, args)
             param = ProtocolParameters(
                 min_fee_constant=result["minFeeConstant"],
                 min_fee_coefficient=result["minFeeCoefficient"],
@@ -130,7 +147,7 @@ def protocol_param(self) -> ProtocolParameters:
                 param.cost_models["PlutusV2"] = param.cost_models.pop("plutus:v2")
 
             args = {"query": "genesisConfig"}
-            result = self._request(method, args)
+            result = self._request(OgmiosQueryType.Query, args)
             param.min_utxo = result["protocolParameters"]["minUtxoValue"]
 
             self._protocol_param = param
@@ -139,10 +156,9 @@ def protocol_param(self) -> ProtocolParameters:
     @property
     def genesis_param(self) -> GenesisParameters:
         """Get chain genesis parameters"""
-        method = "Query"
         args = {"query": "genesisConfig"}
         if not self._genesis_param or self._check_chain_tip_and_update():
-            result = self._request(method, args)
+            result = self._request(OgmiosQueryType.Query, args)
             system_start_unix = int(
                 calendar.timegm(
                     time.strptime(
@@ -174,23 +190,21 @@ def network(self) -> Network:
     @property
     def epoch(self) -> int:
         """Current epoch number"""
-        method = "Query"
         args = {"query": "currentEpoch"}
-        return self._request(method, args)
+        return self._request(OgmiosQueryType.Query, args)
 
     @property
     def last_block_slot(self) -> int:
         """Slot number of last block"""
-        method = "Query"
         args = {"query": "chainTip"}
-        return self._request(method, args)["slot"]
+        return self._request(OgmiosQueryType.Query, args)["slot"]
 
-    def _extract_asset_info(self, asset_hash: str):
+    def _extract_asset_info(self, asset_hash: str) -> Tuple[str, ScriptHash, AssetName]:
         policy_hex, asset_name_hex = asset_hash.split(".")
         policy = ScriptHash.from_primitive(policy_hex)
-        asset_name_hex = AssetName.from_primitive(asset_name_hex)
+        asset_name = AssetName.from_primitive(asset_name_hex)
 
-        return policy_hex, policy, asset_name_hex
+        return policy_hex, policy, asset_name
 
     def _check_utxo_unspent(self, tx_id: str, index: int) -> bool:
         """Check whether an UTxO is unspent with Ogmios.
@@ -200,9 +214,8 @@ def _check_utxo_unspent(self, tx_id: str, index: int) -> bool:
             index (int): transaction index.
         """
 
-        method = "Query"
         args = {"query": {"utxo": [{"txId": tx_id, "index": index}]}}
-        results = self._request(method, args)
+        results = self._request(OgmiosQueryType.Query, args)
 
         if results:
             return True
@@ -220,6 +233,9 @@ def _utxos_kupo(self, address: str) -> List[UTxO]:
         Returns:
             List[UTxO]: A list of UTxOs.
         """
+        if self._kupo_url is None:
+            raise AssertionError("kupo_url object attribute has not been assigned properly.")
+
         address_url = self._kupo_url + "/" + address
         results = requests.get(address_url).json()
 
@@ -282,9 +298,8 @@ def _utxos_ogmios(self, address: str) -> List[UTxO]:
             List[UTxO]: A list of UTxOs.
         """
 
-        method = "Query"
         args = {"query": {"utxo": [address]}}
-        results = self._request(method, args)
+        results = self._request(OgmiosQueryType.Query, args)
 
         utxos = []
 
@@ -374,9 +389,8 @@ def submit_tx(self, cbor: Union[bytes, str]):
         if isinstance(cbor, bytes):
             cbor = cbor.hex()
 
-        method = "SubmitTx"
         args = {"submit": cbor}
-        result = self._request(method, args)
+        result = self._request(OgmiosQueryType.SubmitTx, args)
         if "SubmitFail" in result:
             raise TransactionFailedException(result["SubmitFail"])
 
@@ -395,9 +409,8 @@ def evaluate_tx(self, cbor: Union[bytes, str]) -> Dict[str, ExecutionUnits]:
         if isinstance(cbor, bytes):
             cbor = cbor.hex()
 
-        method = "EvaluateTx"
         args = {"evaluate": cbor}
-        result = self._request(method, args)
+        result = self._request(OgmiosQueryType.EvaluateTx, args)
         if "EvaluationResult" not in result:
             raise TransactionFailedException(result)
         else:

pycardano/hash.py

@@ -1,6 +1,6 @@
 """All type of hashes in Cardano ledger spec."""
 
-from typing import TypeVar, Union
+from typing import TypeVar, Union, Type
 
 from pycardano.serialization import CBORSerializable
 
@@ -67,7 +67,7 @@ def to_primitive(self) -> bytes:
         return self.payload
 
     @classmethod
-    def from_primitive(cls: T, value: Union[bytes, str]) -> T:
+    def from_primitive(cls: Type[T], value: Union[bytes, str]) -> T:
         if isinstance(value, str):
             value = bytes.fromhex(value)
         return cls(value)

pycardano/key.py

@@ -4,6 +4,7 @@
 
 import json
 import os
+from typing import Type
 
 from nacl.encoding import RawEncoder
 from nacl.hash import blake2b
@@ -61,7 +62,7 @@ def to_primitive(self) -> bytes:
         return self.payload
 
     @classmethod
-    def from_primitive(cls, value: bytes) -> Key:
+    def from_primitive(cls: Type["Key"], value: bytes) -> Key:
         return cls(value)
 
     def to_json(self) -> str:

pycardano/metadata.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
-from typing import Any, ClassVar, List, Union
+from typing import Any, ClassVar, List, Union, Type
 
 from cbor2 import CBORTag
 from nacl.encoding import RawEncoder
@@ -91,7 +91,7 @@ def to_primitive(self) -> Primitive:
         return CBORTag(AlonzoMetadata.TAG, super(AlonzoMetadata, self).to_primitive())
 
     @classmethod
-    def from_primitive(cls: AlonzoMetadata, value: CBORTag) -> AlonzoMetadata:
+    def from_primitive(cls: Type[AlonzoMetadata], value: CBORTag) -> AlonzoMetadata:
         if not hasattr(value, "tag"):
             raise DeserializeException(
                 f"{value} does not match the data schema of AlonzoMetadata."
@@ -111,7 +111,7 @@ def to_primitive(self) -> Primitive:
         return self.data.to_primitive()
 
     @classmethod
-    def from_primitive(cls: AuxiliaryData, value: Primitive) -> AuxiliaryData:
+    def from_primitive(cls: Type[AuxiliaryData], value: Primitive) -> AuxiliaryData:
         for t in [AlonzoMetadata, ShellayMarryMetadata, Metadata]:
             # The schema of metadata in different eras are mutually exclusive, so we can try deserializing
             # them one by one without worrying about mismatch.

pycardano/nativescript.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
-from typing import ClassVar, List, Union
+from typing import ClassVar, List, Union, Type
 
 from nacl.encoding import RawEncoder
 from nacl.hash import blake2b
@@ -27,7 +27,7 @@
 class NativeScript(ArrayCBORSerializable):
     @classmethod
     def from_primitive(
-        cls: NativeScript, value: Primitive
+        cls: Type[NativeScript], value: Primitive
     ) -> Union[
         ScriptPubkey, ScriptAll, ScriptAny, ScriptNofK, InvalidBefore, InvalidHereAfter
     ]:

pycardano/network.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 from enum import Enum
+from typing import Type
 
 from pycardano.serialization import CBORSerializable
 
@@ -21,5 +22,5 @@ def to_primitive(self) -> int:
         return self.value
 
     @classmethod
-    def from_primitive(cls, value: int) -> Network:
+    def from_primitive(cls: Type[Network], value: int) -> Network:
         return cls(value)

pycardano/plutus.py

@@ -6,7 +6,7 @@
 import json
 from dataclasses import dataclass, field, fields
 from enum import Enum
-from typing import Any, ClassVar, List, Optional, Union
+from typing import Any, ClassVar, List, Optional, Union, Type
 
 import cbor2
 from cbor2 import CBORTag
@@ -66,7 +66,7 @@ def to_shallow_primitive(self) -> dict:
         return result
 
     @classmethod
-    def from_primitive(cls: CostModels, value: dict) -> CostModels:
+    def from_primitive(cls: Type[CostModels], value: dict) -> CostModels:
         raise DeserializeException(
             "Deserialization of cost model is impossible, because some information is lost "
             "during serialization."
@@ -480,7 +480,7 @@ def to_shallow_primitive(self) -> CBORTag:
             return CBORTag(102, [self.CONSTR_ID, primitives])
 
     @classmethod
-    def from_primitive(cls: PlutusData, value: CBORTag) -> PlutusData:
+    def from_primitive(cls: Type[PlutusData], value: CBORTag) -> PlutusData:
         if not isinstance(value, CBORTag):
             raise DeserializeException(
                 f"Unexpected type: {CBORTag}. Got {type(value)} instead."
@@ -643,7 +643,7 @@ def _dfs(obj):
         return _dfs(self.data)
 
     @classmethod
-    def from_primitive(cls: RawPlutusData, value: CBORTag) -> RawPlutusData:
+    def from_primitive(cls: Type[RawPlutusData], value: CBORTag) -> RawPlutusData:
         return cls(value)
 
 
@@ -675,7 +675,7 @@ def to_primitive(self) -> int:
         return self.value
 
     @classmethod
-    def from_primitive(cls, value: int) -> RedeemerTag:
+    def from_primitive(cls: Type[RedeemerTag], value: int) -> RedeemerTag:
         return cls(value)
 
 
@@ -704,7 +704,7 @@ class Redeemer(ArrayCBORSerializable):
     ex_units: ExecutionUnits = None
 
     @classmethod
-    def from_primitive(cls: Redeemer, values: List[Primitive]) -> Redeemer:
+    def from_primitive(cls: Type[Redeemer], values: List[Primitive]) -> Redeemer:
         if isinstance(values[2], CBORTag) and cls is Redeemer:
             values[2] = RawPlutusData.from_primitive(values[2])
         redeemer = super(Redeemer, cls).from_primitive(

pycardano/serialization.py

@@ -222,7 +222,7 @@ def to_validated_primitive(self) -> Primitive:
         return self.to_primitive()
 
     @classmethod
-    def from_primitive(cls: CBORBase, value: Primitive) -> CBORBase:
+    def from_primitive(cls: Type[CBORBase], value: Primitive) -> CBORBase:
         """Turn a CBOR primitive to its original class type.
 
         Args:
@@ -473,7 +473,7 @@ def to_shallow_primitive(self) -> List[Primitive]:
         return primitives
 
     @classmethod
-    def from_primitive(cls: ArrayBase, values: List[Primitive]) -> ArrayBase:
+    def from_primitive(cls: Type[ArrayBase], values: List[Primitive]) -> ArrayBase:
         """Restore a primitive value to its original class type.
 
         Args:
@@ -585,7 +585,7 @@ def to_shallow_primitive(self) -> Primitive:
         return primitives
 
     @classmethod
-    def from_primitive(cls: MapBase, values: Primitive) -> MapBase:
+    def from_primitive(cls: Type[MapBase], values: Primitive) -> MapBase:
         """Restore a primitive value to its original class type.
 
         Args:
@@ -704,7 +704,7 @@ def _get_sortable_val(key):
         return dict(sorted(self.data.items(), key=lambda x: _get_sortable_val(x[0])))
 
     @classmethod
-    def from_primitive(cls: DictBase, value: dict) -> DictBase:
+    def from_primitive(cls: Type[DictBase], value: dict) -> DictBase:
         """Restore a primitive value to its original class type.
 
         Args: