Added IbftGetValidatorsByBlockHash json rpc and corresponding test. (#519)

consensus/ibft/src/main/java/tech/pegasys/pantheon/consensus/ibft/jsonrpc/methods/IbftGetValidatorsByBlockHash.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.consensus.ibft.jsonrpc.methods;
+
+import tech.pegasys.pantheon.consensus.ibft.IbftBlockInterface;
+import tech.pegasys.pantheon.ethereum.chain.Blockchain;
+import tech.pegasys.pantheon.ethereum.core.BlockHeader;
+import tech.pegasys.pantheon.ethereum.core.Hash;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.JsonRpcRequest;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.methods.JsonRpcMethod;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.parameters.JsonRpcParameter;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcResponse;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcSuccessResponse;
+
+import java.util.Optional;
+
+public class IbftGetValidatorsByBlockHash implements JsonRpcMethod {
+
+  private final Blockchain blockchain;
+  private final IbftBlockInterface ibftBlockInterface;
+  private final JsonRpcParameter parameters;
+
+  public IbftGetValidatorsByBlockHash(
+      final Blockchain blockchain,
+      final IbftBlockInterface ibftBlockInterface,
+      final JsonRpcParameter parameters) {
+    this.blockchain = blockchain;
+    this.ibftBlockInterface = ibftBlockInterface;
+    this.parameters = parameters;
+  }
+
+  @Override
+  public String getName() {
+    return "ibft_getValidatorsByBlockHash";
+  }
+
+  @Override
+  public JsonRpcResponse response(final JsonRpcRequest request) {
+    return new JsonRpcSuccessResponse(request.getId(), blockResult(request));
+  }
+
+  private Object blockResult(final JsonRpcRequest request) {
+    final Hash hash = parameters.required(request.getParams(), 0, Hash.class);
+    final Optional<BlockHeader> blockHeader = blockchain.getBlockHeader(hash);
+    return blockHeader.map(header -> ibftBlockInterface.validatorsInBlock(header)).orElse(null);
+  }
+}

consensus/ibft/src/test/java/tech/pegasys/pantheon/consensus/ibft/jsonrpc/methods/IbftGetValidatorsByBlockHashTest.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.consensus.ibft.jsonrpc.methods;
+
+import static org.mockito.Mockito.when;
+
+import tech.pegasys.pantheon.consensus.ibft.IbftBlockInterface;
+import tech.pegasys.pantheon.ethereum.chain.Blockchain;
+import tech.pegasys.pantheon.ethereum.core.Address;
+import tech.pegasys.pantheon.ethereum.core.BlockHeader;
+import tech.pegasys.pantheon.ethereum.core.Hash;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.JsonRpcRequest;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.parameters.JsonRpcParameter;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcSuccessResponse;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+
+import org.assertj.core.api.Assertions;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+@RunWith(MockitoJUnitRunner.class)
+public class IbftGetValidatorsByBlockHashTest {
+
+  private static final String ETH_METHOD = "ibft_getValidatorsByBlockHash";
+  private static final String JSON_RPC_VERSION = "2.0";
+  private static final String ZERO_HASH = String.valueOf(Hash.ZERO);
+
+  @Mock private Blockchain blockchain;
+  @Mock private BlockHeader blockHeader;
+  @Mock private IbftBlockInterface ibftBlockInterface;
+  @Mock private JsonRpcRequest request;
+
+  private final JsonRpcParameter parameters = new JsonRpcParameter();
+  private IbftGetValidatorsByBlockHash method;
+
+  @Before
+  public void setUp() {
+    method = new IbftGetValidatorsByBlockHash(blockchain, ibftBlockInterface, parameters);
+  }
+
+  @Test
+  public void nameShouldBeCorrect() {
+    Assertions.assertThat(method.getName()).isEqualTo(ETH_METHOD);
+  }
+
+  @Test
+  public void shouldReturnListOfValidatorsFromBlock() {
+    when(blockchain.getBlockHeader(Hash.ZERO)).thenReturn(Optional.of(blockHeader));
+    final List<Address> addresses = Collections.singletonList(Address.ID);
+    when(ibftBlockInterface.validatorsInBlock(blockHeader)).thenReturn(addresses);
+    request = requestWithParams(ZERO_HASH);
+    JsonRpcSuccessResponse response = (JsonRpcSuccessResponse) method.response(request);
+    Assertions.assertThat(response.getResult()).isEqualTo(addresses);
+  }
+
+  private JsonRpcRequest requestWithParams(final Object... params) {
+    return new JsonRpcRequest(JSON_RPC_VERSION, ETH_METHOD, params);
+  }
+}