WalletAccountPathTest: create wallets in temp dir and verify account paths

integration-test/build.gradle

@@ -9,6 +9,7 @@ dependencies {
 
     testImplementation 'org.slf4j:slf4j-jdk14:1.7.36'
     testImplementation "org.junit.jupiter:junit-jupiter-api:5.8.2"
+    testImplementation "org.junit.jupiter:junit-jupiter-params:5.8.2"
     testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:5.8.2"
 }
 

integration-test/src/test/java/org/bitcoinj/wallet/WalletAccountPathTest.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright by the original author or authors.
+ *
+ * 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 org.bitcoinj.wallet;
+
+import org.bitcoinj.core.Context;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.crypto.HDPath;
+import org.bitcoinj.script.Script;
+import org.bitcoinj.utils.Network;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.io.TempDir;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.io.File;
+import java.io.IOException;
+import java.time.Instant;
+import java.util.stream.Stream;
+
+import static org.bitcoinj.script.Script.ScriptType.P2PKH;
+import static org.bitcoinj.script.Script.ScriptType.P2WPKH;
+import static org.bitcoinj.utils.Network.MAIN;
+import static org.bitcoinj.utils.Network.TEST;
+import static org.bitcoinj.wallet.KeyChainGroupStructure.BIP43;
+import static org.bitcoinj.wallet.KeyChainGroupStructure.DEFAULT;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Create new Wallets in a temp directory and make sure their account paths are correct.
+ */
+public class WalletAccountPathTest {
+    private static final String testWalletMnemonic = "panda diary marriage suffer basic glare surge auto scissors describe sell unique";
+
+    @TempDir File tempDir;
+    File walletFile;
+
+    @BeforeEach
+    void setupTest() {
+        walletFile = new File(tempDir, "test.wallet");
+    }
+
+    @MethodSource("walletStructureParams")
+    @ParameterizedTest(name = "path {1} generated for {2}, {3}")
+    void walletStructurePathTest2(KeyChainGroupStructure structure, HDPath expectedPath, Script.ScriptType scriptType,
+                                  Network network) throws IOException, UnreadableWalletException {
+        // When we create a wallet with parameterized structure, network, and scriptType
+        Wallet wallet = createWallet(walletFile, network.networkParameters(), structure, scriptType);
+
+        // Then the account path is as expected
+        assertEquals(expectedPath, wallet.getActiveKeyChain().getAccountPath());
+    }
+
+    private static Stream<Arguments> walletStructureParams() {
+        return Stream.of(
+            // Note: For BIP32 wallets the Network does not affect the path
+            Arguments.of(DEFAULT, "M/0H", P2PKH,  MAIN),
+            Arguments.of(DEFAULT, "M/0H", P2PKH,  TEST),
+            Arguments.of(DEFAULT, "M/1H", P2WPKH, MAIN),
+            Arguments.of(DEFAULT, "M/1H", P2WPKH, TEST),
+            Arguments.of(BIP43, "M/44H/0H/0H", P2PKH, MAIN),
+            Arguments.of(BIP43, "M/44H/1H/0H", P2PKH, TEST),
+            Arguments.of(BIP43, "M/84H/0H/0H", P2WPKH, MAIN),
+            Arguments.of(BIP43, "M/84H/1H/0H", P2WPKH, TEST)
+        );
+    }
+
+    // Create a wallet, save it to a file, then reload from a file
+    private static Wallet createWallet(File walletFile, NetworkParameters params, KeyChainGroupStructure structure, Script.ScriptType outputScriptType) throws IOException, UnreadableWalletException {
+        Context.propagate(new Context(params));
+        DeterministicSeed seed = new DeterministicSeed(testWalletMnemonic, null, "", Instant.now().getEpochSecond());
+        KeyChainGroup keyChainGroup = KeyChainGroup.builder(params, structure)
+                .fromSeed(seed, outputScriptType)
+                .build();
+        Wallet memoryWallet = new Wallet(params, keyChainGroup);
+        memoryWallet.saveToFile(walletFile);
+        return Wallet.loadFromFile(walletFile);
+    }
+}