New: Sample test for auto-shielding.

Trying a new approach to writing sample tests that can serve as code examples.

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

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+package cash.z.ecc.android.sdk.jni
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import cash.z.ecc.android.bip39.Mnemonics.MnemonicCode
+import cash.z.ecc.android.bip39.Mnemonics.WordCount.COUNT_24
+import cash.z.ecc.android.bip39.toSeed
+import cash.z.ecc.android.sdk.ext.TroubleshootingTwig
+import cash.z.ecc.android.sdk.ext.Twig
+import cash.z.ecc.android.sdk.ext.twig
+import cash.z.ecc.android.sdk.tool.DerivationTool
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.BeforeClass
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class TransparentTest {
+
+    @Before
+    fun setup() {
+
+    }
+
+    @Test
+    fun deriveTransparentSecretKeyTest() {
+        assertEquals(Expected.tskCompressed, DerivationTool.deriveTransparentSecretKey(SEED))
+    }
+
+    @Test
+    fun deriveTransparentAddressTest() {
+        assertEquals(Expected.tAddr, DerivationTool.deriveTransparentAddress(SEED))
+    }
+
+    @Test
+    fun deriveTransparentAddressFromSecretKeyTest() {
+        assertEquals(Expected.tAddr, DerivationTool.deriveTransparentAddress(Expected.tskCompressed))
+    }
+
+//    @Test
+//    fun deriveTransparentAddressFromSecretKeyTest2() {
+//        while(false) {
+//            MnemonicCode(COUNT_24).let { phrase ->
+//                val addr = DerivationTool.deriveShieldedAddress(phrase.toSeed())
+//                twig("$addr${String(phrase.chars)}\t")
+//            }
+//        }
+//    }
+
+
+    companion object {
+        const val PHRASE = "deputy visa gentle among clean scout farm drive comfort patch skin salt ranch cool ramp warrior drink narrow normal lunch behind salt deal person"
+        val MNEMONIC = MnemonicCode(PHRASE)
+        val SEED = MNEMONIC.toSeed()
+
+        object Expected {
+            val tAddr = "t1PKtYdJJHhc3Pxowmznkg7vdTwnhEsCvR4"
+
+            // private key in compressed Wallet Import Format (WIF)
+            val tskCompressed = "L4BvDC33yLjMRxipZvdiUmdYeRfZmR8viziwsVwe72zJdGbiJPv2"
+        }
+
+        @BeforeClass
+        @JvmStatic
+        fun startup() {
+            Twig.plant(TroubleshootingTwig(formatter = {"@TWIG $it"}))
+        }
+    }
+}

src/androidTest/java/cash/z/ecc/android/sdk/sample/ShieldFundsSample.kt

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+package cash.z.ecc.android.sdk.sample
+
+import androidx.test.platform.app.InstrumentationRegistry
+import cash.z.ecc.android.bip39.Mnemonics
+import cash.z.ecc.android.bip39.toSeed
+import cash.z.ecc.android.sdk.Initializer
+import cash.z.ecc.android.sdk.Synchronizer
+import cash.z.ecc.android.sdk.Synchronizer.Status.SYNCED
+import cash.z.ecc.android.sdk.ext.TroubleshootingTwig
+import cash.z.ecc.android.sdk.ext.Twig
+import cash.z.ecc.android.sdk.ext.twig
+import cash.z.ecc.android.sdk.tool.DerivationTool
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.onCompletion
+import kotlinx.coroutines.newFixedThreadPoolContext
+import kotlinx.coroutines.runBlocking
+import org.junit.Assert
+import org.junit.Test
+
+/**
+ * Samples related to shielding funds.
+ */
+class ShieldFundsSample {
+
+    val SEED_PHRASE = "wish puppy smile loan doll curve hole maze file ginger hair nose key relax knife witness cannon grab despair throw review deal slush frame"//\"still champion voice habit trend flight survey between bitter process artefact blind carbon truly provide dizzy crush flush breeze blouse charge solid fish spread\"//\"deputy visa gentle among clean scout farm drive comfort patch skin salt ranch cool ramp warrior drink narrow normal lunch behind salt deal person"//"deputy visa gentle among clean scout farm drive comfort patch skin salt ranch cool ramp warrior drink narrow normal lunch behind salt deal person"
+
+    // simple flag to turn off actually spending funds
+    val IS_DRY_RUN = true
+
+    /**
+     * This test will construct a t2z transaction. It is safe to run this repeatedly, because
+     * nothing is submitted to the network (because the keys don't match the address so the encoding
+     * fails). Originally, it's intent is just to exercise the code and troubleshoot any issues but
+     * then it became clear that this would be a cool Sample Test and PoC for writing a SimpleWallet
+     * class.
+     */
+    @Test
+    fun constructT2Z() = runBlocking {
+        Twig.sprout("ShieldFundsSample")
+
+        val wallet = SimpleWallet(SEED_PHRASE).sync()
+        wallet.shieldFunds()
+
+        Twig.clip("ShieldFundsSample")
+        Assert.assertEquals(5, wallet.synchronizer.latestBalance.availableZatoshi)
+    }
+
+
+    // when startHeight is null, it will use the latest checkpoint
+    class SimpleWallet(seedPhrase: String, startHeight: Int? = null) {
+        val walletScope = CoroutineScope(
+            SupervisorJob() + newFixedThreadPoolContext(3, this.javaClass.simpleName)
+        )
+        private val context = InstrumentationRegistry.getInstrumentation().context
+        private val seed: ByteArray = Mnemonics.MnemonicCode(seedPhrase).toSeed()
+        private val shieldedSpendingKey = DerivationTool.deriveSpendingKeys(seed)[0]
+        private val transparentSecretKey = DerivationTool.deriveTransparentSecretKey(seed)
+        private val shieldedAddress = DerivationTool.deriveShieldedAddress(seed)
+
+        // t1b9Y6PESSGavavgge3ruTtX9X83817V29s
+        private val transparentAddress = DerivationTool.deriveTransparentAddress(seed)
+
+        private val config = Initializer.Config {
+            it.setSeed(seed)
+            it.setBirthdayHeight(startHeight, false)
+            it.server("lightwalletd.electriccoin.co", 9067)
+        }
+
+        val synchronizer = Synchronizer(Initializer(context, config))
+
+        suspend fun sync(): SimpleWallet {
+            twig("Starting sync")
+            synchronizer.start(walletScope)
+            // block until synced
+            synchronizer.status.first { it == SYNCED }
+            twig("Synced!")
+            return this
+        }
+
+        suspend fun shieldFunds(): SimpleWallet {
+            twig("checking $transparentAddress for transactions!")
+            synchronizer.refreshUtxos(transparentAddress, 935000).let { count ->
+                twig("FOUND $count new UTXOs")
+            }
+
+            synchronizer.getTransparentBalance(transparentAddress).let { walletBalance ->
+                twig("FOUND utxo balance of total: ${walletBalance.totalZatoshi}  available: ${walletBalance.availableZatoshi}")
+
+                if (walletBalance.availableZatoshi > 0L && !IS_DRY_RUN) {
+                    synchronizer.shieldFunds(shieldedSpendingKey, transparentSecretKey)
+                        .onCompletion { twig("done shielding funds") }
+                        .catch { twig("Failed with $it") }
+                        .collect()
+                }
+            }
+
+            return this
+        }
+
+        companion object {
+            init {
+                Twig.plant(TroubleshootingTwig())
+            }
+        }
+    }
+}