Add simple tests for Account and UnifiedSpendingKey

test

.gitignore

@@ -81,3 +81,4 @@ DecompileChecker.kt
 backup-dbs/
 *.db
 .DS_Store
+/.idea/androidTestResultsUserPreferences.xml

sdk-lib/build.gradle.kts

@@ -287,8 +287,6 @@ dependencies {
     // Tests
     testImplementation(libs.kotlin.reflect)
     testImplementation(libs.kotlin.test)
-    testImplementation(libs.mockito.junit)
-    testImplementation(libs.mockito.kotlin)
     testImplementation(libs.bundles.junit)
     testImplementation(libs.grpc.testing)
 

sdk-lib/src/androidTest/java/cash/z/ecc/android/sdk/fixture/WalletFixture.kt

@@ -0,0 +1,18 @@
+package cash.z.ecc.android.sdk.fixture
+
+import cash.z.ecc.android.bip39.Mnemonics
+import cash.z.ecc.android.sdk.model.Account
+import cash.z.ecc.android.sdk.model.ZcashNetwork
+import cash.z.ecc.android.sdk.tool.DerivationTool
+
+object WalletFixture {
+    val NETWORK = ZcashNetwork.Mainnet
+    const val SEED_PHRASE =
+        "kitchen renew wide common vague fold vacuum tilt amazing pear square gossip jewel month tree shock scan alpha just spot fluid toilet view dinner"
+
+    suspend fun getUnifiedSpendingKey(
+        seed: String = SEED_PHRASE,
+        network: ZcashNetwork = NETWORK,
+        account: Account = Account.DEFAULT
+    ) = DerivationTool.deriveUnifiedSpendingKey(Mnemonics.MnemonicCode(seed).toEntropy(), network, account)
+}

sdk-lib/src/androidTest/java/cash/z/ecc/android/sdk/jni/TransparentTest.kt

@@ -28,8 +28,7 @@ class TransparentTest(val expected: Expected, val network: ZcashNetwork) {
             expected.tAccountPrivKey,
             DerivationTool.deriveTransparentAccountPrivateKey(
                 SEED,
-                network =
+                network = network,
-                network,
                 Account.DEFAULT
             )
         )

sdk-lib/src/androidTest/java/cash/z/ecc/android/sdk/model/UnifiedSpendingKeyTest.kt

@@ -0,0 +1,51 @@
+package cash.z.ecc.android.sdk.model
+
+import androidx.test.filters.SmallTest
+import cash.z.ecc.android.sdk.fixture.WalletFixture
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+import kotlin.test.assertContentEquals
+import kotlin.test.assertEquals
+
+class UnifiedSpendingKeyTest {
+    @Test
+    @SmallTest
+    fun factory_copies_bytes() = runTest {
+        val spendingKey = WalletFixture.getUnifiedSpendingKey()
+        val expected = spendingKey.copyBytes().copyOf()
+
+        val bytes = spendingKey.copyBytes()
+        val newSpendingKey = UnifiedSpendingKey.new(spendingKey.account, bytes)
+        bytes.clear()
+
+        assertContentEquals(expected, newSpendingKey.getOrThrow().copyBytes())
+    }
+
+    @Test
+    @SmallTest
+    fun get_copies_bytes() = runTest {
+        val spendingKey = WalletFixture.getUnifiedSpendingKey()
+
+        val expected = spendingKey.copyBytes()
+        val newSpendingKey = UnifiedSpendingKey.new(spendingKey.account, expected)
+
+        newSpendingKey.getOrThrow().copyBytes().clear()
+
+        assertContentEquals(expected, newSpendingKey.getOrThrow().copyBytes())
+    }
+
+    @Test
+    @SmallTest
+    fun toString_does_not_leak() = runTest {
+        assertEquals(
+            "UnifiedSpendingKey(account=Account(value=0))",
+            WalletFixture.getUnifiedSpendingKey().toString()
+        )
+    }
+}
+
+private fun ByteArray.clear() {
+    for (i in indices) {
+        this[i] = 0
+    }
+}

sdk-lib/src/androidTest/java/cash/z/ecc/android/sdk/tool/DerivationToolTest.kt

@@ -0,0 +1,20 @@
+package cash.z.ecc.android.sdk.tool
+
+import cash.z.ecc.android.bip39.Mnemonics
+import cash.z.ecc.android.sdk.fixture.WalletFixture
+import cash.z.ecc.android.sdk.model.Account
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+import kotlin.test.assertContentEquals
+
+class DerivationToolTest {
+    @Test
+    fun create_spending_key_does_not_mutate_passed_bytes() = runTest {
+        val bytesOne = Mnemonics.MnemonicCode(WalletFixture.SEED_PHRASE).toEntropy()
+        val bytesTwo = Mnemonics.MnemonicCode(WalletFixture.SEED_PHRASE).toEntropy()
+
+        DerivationTool.deriveUnifiedSpendingKey(bytesOne, WalletFixture.NETWORK, Account.DEFAULT)
+
+        assertContentEquals(bytesTwo, bytesOne)
+    }
+}

sdk-lib/src/main/java/cash/z/ecc/android/sdk/jni/RustBackend.kt

@@ -233,7 +233,7 @@ internal class RustBackend private constructor(
         createToAddress(
             dataDbFile.absolutePath,
             usk.account.value,
-            usk.bytes.byteArray,
+            usk.copyBytes(),
             to,
             value,
             memo ?: ByteArray(0),
@@ -252,7 +252,7 @@ internal class RustBackend private constructor(
             shieldToAddress(
                 dataDbFile.absolutePath,
                 usk.account.value,
-                usk.bytes.byteArray,
+                usk.copyBytes(),
                 memo ?: ByteArray(0),
                 "$pathParamsDir/$SPEND_PARAM_FILE_NAME",
                 "$pathParamsDir/$OUTPUT_PARAM_FILE_NAME",

sdk-lib/src/main/java/cash/z/ecc/android/sdk/model/UnifiedSpendingKey.kt

@@ -11,7 +11,7 @@ import cash.z.ecc.android.sdk.jni.RustBackend
  * derived at the time of its creation. As such, it is not suitable for long-term storage,
  * export/import, or backup purposes.
  */
-data class UnifiedSpendingKey internal constructor(
+class UnifiedSpendingKey private constructor(
     val account: Account,
 
     /**
@@ -22,12 +22,42 @@ data class UnifiedSpendingKey internal constructor(
      * inherently unstable, and only intended to be passed between the SDK and the storage
      * backend. Wallets **MUST NOT** allow this encoding to be exported or imported.
      */
-    internal val bytes: FirstClassByteArray
+    private val bytes: FirstClassByteArray
 ) {
+
+    // This constructor exists solely for the JNI
+    internal constructor(account: Int, bytes: ByteArray) : this(Account(account), FirstClassByteArray(bytes.copyOf()))
+
+    /**
+     * The binary encoding of the [ZIP 316](https://zips.z.cash/zip-0316) Unified Spending
+     * Key for [account].
+     *
+     * This encoding **MUST NOT** be exposed to users. It is an internal encoding that is
+     * inherently unstable, and only intended to be passed between the SDK and the storage
+     * backend. Wallets **MUST NOT** allow this encoding to be exported or imported.
+     */
+    fun copyBytes() = bytes.byteArray.copyOf()
+
     // Override to prevent leaking key to logs
     override fun toString() = "UnifiedSpendingKey(account=$account)"
 
-    fun copyBytes() = bytes.byteArray.copyOf()
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (javaClass != other?.javaClass) return false
+
+        other as UnifiedSpendingKey
+
+        if (account != other.account) return false
+        if (bytes != other.bytes) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        var result = account.hashCode()
+        result = 31 * result + bytes.hashCode()
+        return result
+    }
 
     companion object {
 

sdk-lib/src/main/java/cash/z/ecc/android/sdk/tool/DerivationTool.kt

@@ -45,7 +45,7 @@ class DerivationTool {
             network: ZcashNetwork
         ): UnifiedFullViewingKey = withRustBackendLoaded {
             UnifiedFullViewingKey(
-                deriveUnifiedFullViewingKey(usk.bytes.byteArray, networkId = network.id)
+                deriveUnifiedFullViewingKey(usk.copyBytes(), networkId = network.id)
             )
         }
 

sdk-lib/src/test/java/cash/z/ecc/android/sdk/ext/ConversionsTest.kt

@@ -6,7 +6,7 @@ import java.math.BigDecimal
 import java.math.MathContext
 import kotlin.test.assertEquals
 
-internal class ConversionsTest {
+class ConversionsTest {
 
     @Test
     fun `default right padding is 6`() {

sdk-lib/src/test/java/cash/z/ecc/android/sdk/model/AccountTest.kt

@@ -0,0 +1,13 @@
+package cash.z.ecc.android.sdk.model
+
+import org.junit.Test
+import kotlin.test.assertFailsWith
+
+class AccountTest {
+    @Test
+    fun out_of_bounds() {
+        assertFailsWith(IllegalArgumentException::class) {
+            Account(-1)
+        }
+    }
+}