test: add electrum client test

bdk-jvm/lib/src/test/kotlin/org/bitcoindevkit/LiveElectrumClientTest.kt

@@ -0,0 +1,35 @@
+package org.bitcoindevkit
+
+import kotlin.test.Test
+
+private const val SIGNET_ELECTRUM_URL = "ssl://mempool.space:60602"
+
+class LiveElectrumClientTest {
+    @Test
+    fun testSyncedBalance() {
+        val descriptor: Descriptor = Descriptor(
+            "wpkh(tprv8ZgxMBicQKsPf2qfrEygW6fdYseJDDrVnDv26PH5BHdvSuG6ecCbHqLVof9yZcMoM31z9ur3tTYbSnr1WBqbGX97CbXcmp5H6qeMpyvx35B/84h/1h/0h/0/*)",
+            Network.SIGNET
+        )
+        val wallet: Wallet = Wallet.newNoPersist(descriptor, null, Network.SIGNET)
+        val electrumClient: ElectrumClient = ElectrumClient(SIGNET_ELECTRUM_URL)
+        val fullScanRequest: FullScanRequest = wallet.startFullScan()
+        val update = electrumClient.fullScan(fullScanRequest, 10uL, 10uL, false)
+        wallet.applyUpdate(update)
+        wallet.commit()
+        println("Balance: ${wallet.getBalance().total.toSat()}")
+
+        assert(wallet.getBalance().total.toSat() > 0uL) {
+            "Wallet balance must be greater than 0! Please send funds to ${wallet.revealNextAddress(KeychainKind.EXTERNAL).address.asString()} and try again."
+        }
+
+        println("Transactions count: ${wallet.transactions().count()}")
+        val transactions = wallet.transactions().take(3)
+        for (tx in transactions) {
+            val sentAndReceived = wallet.sentAndReceived(tx.transaction)
+            println("Transaction: ${tx.transaction.txid()}")
+            println("Sent ${sentAndReceived.sent.toSat()}")
+            println("Received ${sentAndReceived.received.toSat()}")
+        }
+    }
+}