test: add tests for single-descriptor wallets

Author: thunderbiscuit

lib/src/test/kotlin/org/bitcoindevkit/CreatingWalletTest.kt

@@ -29,6 +29,15 @@ class CreatingWalletTest {
             )
         }
 
+        @Test
+        fun `Create a wallet with a single descriptor`() {
+            Wallet.createSingle(
+                descriptor = TEST_BIP84_DESCRIPTOR,
+                network = Network.TESTNET4,
+                persister = conn
+            )
+        }
+
         @Test
         fun `Create a wallet with a non-extended descriptor`() {
             Wallet(

lib/src/test/kotlin/org/bitcoindevkit/WalletTest.kt

@@ -40,4 +40,24 @@ class WalletTest {
             actual = wallet.balance().total.toSat()
         )
     }
+
+    // Single-descriptor wallets return an address on the external keychain even if a change descriptor is not provided
+    // and the wallet.revealNextAddress(KeychainKind.INTERNAL) or wallet.peekAddress(KeychainKind.EXTERNAL, 0u) APIs are
+    // used.
+    @Test
+    fun `Single-descriptor wallets can create addresses`() {
+        val wallet: Wallet = Wallet.createSingle(
+            descriptor = TEST_BIP84_DESCRIPTOR,
+            network = Network.TESTNET4,
+            persister = conn
+        )
+        val address1 = wallet.peekAddress(KeychainKind.EXTERNAL, 0u)
+        val address2 = wallet.peekAddress(KeychainKind.INTERNAL, 0u)
+
+        assertEquals(
+            expected = address1.address,
+            actual = address2.address,
+            message = "Addresses should be the same"
+        )
+    }
 }