New: Unit test to verify the logic for getting the client's consensus branch id.

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

@@ -0,0 +1,56 @@
+package cash.z.ecc.android.sdk.jni
+
+import cash.z.ecc.android.sdk.annotation.MaintainedTest
+import cash.z.ecc.android.sdk.annotation.TestPurpose
+import cash.z.ecc.android.sdk.type.ZcashNetwork
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.Parameterized
+
+/**
+ * This test is intended to run to make sure that branch ID logic works across all target devices.
+ */
+@MaintainedTest(TestPurpose.REGRESSION)
+@RunWith(Parameterized::class)
+class BranchIdTest(
+    private val networkName: String,
+    private val height: Int,
+    private val branchHex: String,
+    private val rustBackend: RustBackendWelding
+) {
+
+    @Test
+    fun testBranchId() {
+        val branchId = rustBackend.getBranchIdForHeight(height)
+        val clientBranch = "%x".format(branchId)
+        assertEquals("Invalid branch ID for $networkName at height $height on ${rustBackend.network.networkName}", branchHex, clientBranch)
+    }
+
+    companion object {
+
+        @JvmStatic
+        @Parameterized.Parameters
+        fun wallets(): List<Array<Any>> {
+            // init values don't matter for this test because we're just checking branchIds, which
+            // is an abnormal use of the SDK because this really should run at the rust level
+            // However, due to quirks on certain devices, we created this test at the Android level,
+            // as a sanity check
+            val testnetBackend = RustBackend.init("", "", "", ZcashNetwork.Testnet)
+            val mainnetBackend = RustBackend.init("", "", "", ZcashNetwork.Mainnet)
+            return listOf(
+                // Mainnet Cases
+                arrayOf("Sapling", 419_200, "76b809bb", mainnetBackend),
+                arrayOf("Blossom", 653_600, "2bb40e60", mainnetBackend),
+                arrayOf("Heartwood", 903_000, "f5b9230b", mainnetBackend),
+                arrayOf("Canopy", 1_046_400, "e9ff75a6", mainnetBackend),
+
+                // Testnet Cases
+                arrayOf("Sapling", 280_000, "76b809bb", testnetBackend),
+                arrayOf("Blossom", 584_000, "2bb40e60", testnetBackend),
+                arrayOf("Heartwood", 903_800, "f5b9230b", testnetBackend),
+                arrayOf("Canopy", 1_028_500, "e9ff75a6", testnetBackend),
+            )
+        }
+    }
+}