Implements InfuraClient by adding an intermediate call to get the var…

…iant of a web3 client.

nucypher/blockchain/eth/clients.py

@@ -83,6 +83,10 @@ def __init__(self,
         self.backend = backend
         self.log = Logger(self.__class__.__name__)
 
+    @classmethod
+    def _get_variant(cls, w3):
+        return cls
+
     @classmethod
     def from_w3(cls, w3: Web3) -> 'Web3Client':
         """
@@ -127,7 +131,7 @@ def from_w3(cls, w3: Web3) -> 'Web3Client':
             'platform': client_data[2] if len(client_data) == 4 else None  # Plaftorm is optional
         }
 
-        instance = ClientSubclass(w3, **client_kwargs)
+        instance = ClientSubclass._get_variant(w3)(w3, **client_kwargs)
         return instance
 
     class ConnectionNotEstablished(RuntimeError):
@@ -253,6 +257,12 @@ def sign_message(self, account: str, message: bytes) -> str:
 
 class GethClient(Web3Client):
 
+    @classmethod
+    def _get_variant(cls, w3):
+        if 'infura' in w3.provider.endpoint_uri:
+            return InfuraClient
+        return cls
+
     @property
     def is_local(self):
         return int(self.w3.net.version) not in PUBLIC_CHAINS
@@ -262,7 +272,8 @@ def peers(self):
         return self.w3.geth.admin.peers()
 
     def unlock_account(self, address, password):
-        return self.w3.geth.personal.unlockAccount(address, password)
+        if not self.is_local:
+            return self.w3.geth.personal.unlockAccount(address, password)
 
 
 class ParityClient(Web3Client):
@@ -289,6 +300,16 @@ def sync(self, *args, **kwargs):
         return True
 
 
+class InfuraClient(Web3Client):
+
+    is_local = False
+
+    def unlock_account(self, address, password):
+        return True
+
+    def sync(self, *args, **kwargs):
+        return True
+
 class EthereumTesterClient(Web3Client):
 
     is_local = True

nucypher/blockchain/eth/interfaces.py

@@ -256,8 +256,7 @@ def provider(self) -> Union[IPCProvider, WebsocketProvider, HTTPProvider]:
 
     def _attach_provider(self,
                          provider: Web3Providers = None,
-                         provider_uri: str = None,
-                         remote: bool = False) -> None:
+                         provider_uri: str = None) -> None:
         """
         https://web3py.readthedocs.io/en/latest/providers.html#providers
         """

tests/blockchain/eth/clients/test_mocked_clients.py

@@ -2,6 +2,7 @@
     GethClient,
     ParityClient,
     GanacheClient,
+    InfuraClient,
     PUBLIC_CHAINS
 )
 from nucypher.blockchain.eth.interfaces import BlockchainInterface
@@ -12,17 +13,25 @@
 #
 
 class MockGethProvider:
+    endpoint_uri = 'file:///ipc.geth'
     clientVersion = 'Geth/v1.4.11-stable-fed692f6/darwin/go1.7'
 
 
 class MockParityProvider:
+    endpoint_uri = 'file:///ipc.parity'
     clientVersion = 'Parity-Ethereum/v2.5.1-beta-e0141f8-20190510/x86_64-linux-gnu/rustc1.34.1'
 
 
 class MockGanacheProvider:
+    endpoint_uri = 'http://ganache:8445'
     clientVersion = 'EthereumJS TestRPC/v2.1.5/ethereum-js'
 
 
+class MockInfuraProvider:
+    endpoint_uri = 'wss://:@goerli.infura.io/ws/v3/1234567890987654321abcdef'
+    clientVersion = 'Geth/v1.8.23-omnibus-2ad89aaa/linux-amd64/go1.11.1'
+
+
 class ChainIdReporter:
     # Support older and newer versions of web3 py in-test
     version = 5
@@ -68,6 +77,9 @@ class GethClientTestBlockchain(BlockchainInterfaceTestBase):
     def _attach_provider(self, *args, **kwargs) -> None:
         super()._attach_provider(provider=MockGethProvider())
 
+    def _get_infura_provider(self):
+        return MockInfuraProvider()
+
     @property
     def is_local(self):
         return int(self.w3.net.version) not in PUBLIC_CHAINS
@@ -97,6 +109,22 @@ def test_geth_web3_client():
     assert interface.client.chain_id == 5
 
 
+def test_infura_web3_client():
+    interface = GethClientTestBlockchain(
+        provider_uri='infura://1234567890987654321abcdef'
+    )
+    assert isinstance(interface.client, InfuraClient)
+    assert interface.node_technology == 'Geth'
+    assert interface.node_version == 'v1.8.23-omnibus-2ad89aaa'
+    assert interface.platform == 'linux-amd64'
+    assert interface.backend == 'go1.11.1'
+
+    assert interface.is_local is False
+    assert interface.chain_id == 5
+
+    assert interface.unlock_account('address', 'password')  # should return True
+
+
 def test_parity_web3_client():
     interface = ParityClientTestInterface(provider_uri='file:///ipc.parity', sync_now=False)
     assert isinstance(interface.client, ParityClient)