[CORDA-2208]: NodeHandles hashcode attemps an RPC invocation. (#4217)

client/rpc/src/main/kotlin/net/corda/client/rpc/internal/RPCClientProxyHandler.kt

@@ -100,6 +100,8 @@ class RPCClientProxyHandler(
         private val log = contextLogger()
         // To check whether toString() is being invoked
         val toStringMethod: Method = Object::toString.javaMethod!!
+        val equalsMethod: Method = Object::equals.javaMethod!!
+        val hashCodeMethod: Method = Object::hashCode.javaMethod!!
 
         private fun addRpcCallSiteToThrowable(throwable: Throwable, callSite: CallSite) {
             var currentThrowable = throwable
@@ -234,7 +236,13 @@ class RPCClientProxyHandler(
         lifeCycle.requireState { it == State.STARTED || it == State.SERVER_VERSION_NOT_SET }
         checkProtocolVersion(method)
         if (method == toStringMethod) {
-            return "Client RPC proxy for $rpcOpsClass"
+            return toString()
+        }
+        if (method == equalsMethod) {
+            return equals(arguments?.getOrNull(0))
+        }
+        if (method == hashCodeMethod) {
+            return hashCode()
         }
         if (consumerSession!!.isClosed) {
             throw RPCException("RPC Proxy is closed")
@@ -364,6 +372,8 @@ class RPCClientProxyHandler(
         close(false)
     }
 
+
+
     /**
      * Closes this handler and sends notifications to all observables, so it can immediately clean up resources.
      * Notifications sent to observables are to be acknowledged, therefore this call blocks until all acknowledgements are received.
@@ -568,6 +578,32 @@ class RPCClientProxyHandler(
         rpcReplyMap.clear()
         callSiteMap?.clear()
     }
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (javaClass != other?.javaClass) return false
+
+        other as RPCClientProxyHandler
+
+        if (rpcUsername != other.rpcUsername) return false
+        if (clientAddress != other.clientAddress) return false
+        if (sessionId != other.sessionId) return false
+        if (targetLegalIdentity != other.targetLegalIdentity) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        var result = rpcUsername.hashCode()
+        result = 31 * result + clientAddress.hashCode()
+        result = 31 * result + sessionId.hashCode()
+        result = 31 * result + (targetLegalIdentity?.hashCode() ?: 0)
+        return result
+    }
+
+    override fun toString(): String {
+        return "{rpcUsername='$rpcUsername', clientAddress=$clientAddress, sessionId=$sessionId, targetLegalIdentity=$targetLegalIdentity}"
+    }
 }
 
 private typealias RpcObservableMap = Cache<InvocationId, UnicastSubject<Notification<*>>>

node/src/integration-test/kotlin/net/corda/node/services/rpc/NodeHandleTests.kt

@@ -0,0 +1,21 @@
+package net.corda.node.services.rpc
+
+import net.corda.core.utilities.getOrThrow
+import net.corda.testing.driver.DriverParameters
+import net.corda.testing.driver.driver
+import org.assertj.core.api.Assertions.assertThatCode
+import org.junit.Test
+
+class NodeHandleTests {
+    @Test
+    fun object_defined_functions_are_static_for_node_rpc_ops() {
+        driver(DriverParameters(startNodesInProcess = true)) {
+            val rpcClient = startNode().getOrThrow().rpc
+
+            assertThatCode { rpcClient.hashCode() }.doesNotThrowAnyException()
+            @Suppress("UnusedEquals")
+            assertThatCode { rpcClient == rpcClient }.doesNotThrowAnyException()
+            assertThatCode { rpcClient.toString() }.doesNotThrowAnyException()
+        }
+    }
+}