test

app/src/test/kotlin/com/bitchat/android/mesh/PacketRelayManagerTest.kt

@@ -0,0 +1,117 @@
+
+package com.bitchat.android.mesh
+
+import com.bitchat.android.model.RoutedPacket
+import com.bitchat.android.protocol.BitchatPacket
+import com.bitchat.android.protocol.MessageType
+import com.bitchat.android.util.toHexString
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Test
+import org.mockito.kotlin.any
+import org.mockito.kotlin.mock
+import org.mockito.kotlin.never
+import org.mockito.kotlin.verify
+import org.mockito.kotlin.whenever
+
+@ExperimentalCoroutinesApi
+class PacketRelayManagerTest {
+
+    private lateinit var packetRelayManager: PacketRelayManager
+    private val delegate: PacketRelayManagerDelegate = mock()
+
+    private val myPeerID = "1111111111111111"
+    private val otherPeerID = "2222222222222222"
+    private val nextHopPeerID = "3333333333333333"
+    private val finalRecipientID = "4444444444444444"
+
+    @Before
+    fun setUp() {
+        packetRelayManager = PacketRelayManager(myPeerID)
+        packetRelayManager.delegate = delegate
+        whenever(delegate.getNetworkSize()).thenReturn(10)
+        whenever(delegate.getBroadcastRecipient()).thenReturn(byteArrayOf(0,0,0,0,0,0,0,0))
+    }
+
+    private fun createPacket(route: List<ByteArray>?, recipient: String? = null): BitchatPacket {
+        return BitchatPacket(
+            type = MessageType.MESSAGE.value,
+            senderID = hexStringToPeerBytes(otherPeerID),
+            recipientID = recipient?.let { hexStringToPeerBytes(it) },
+            timestamp = System.currentTimeMillis().toULong(),
+            payload = "hello".toByteArray(),
+            ttl = 5u,
+            route = route
+        )
+    }
+
+    @Test
+    fun `packet with duplicate hops is dropped`() = runTest {
+        val route = listOf(
+            hexStringToPeerBytes(nextHopPeerID),
+            hexStringToPeerBytes(nextHopPeerID)
+        )
+        val packet = createPacket(route)
+        val routedPacket = RoutedPacket(packet, otherPeerID)
+
+        packetRelayManager.handlePacketRelay(routedPacket)
+
+        verify(delegate, never()).sendToPeer(any(), any())
+        verify(delegate, never()).broadcastPacket(any())
+    }
+
+    @Test
+    fun `valid source-routed packet is relayed to next hop`() = runTest {
+        val route = listOf(
+            hexStringToPeerBytes(myPeerID),
+            hexStringToPeerBytes(nextHopPeerID)
+        )
+        val packet = createPacket(route, finalRecipientID)
+        val routedPacket = RoutedPacket(packet, otherPeerID)
+        whenever(delegate.sendToPeer(any(), any())).thenReturn(true)
+
+        packetRelayManager.handlePacketRelay(routedPacket)
+
+        verify(delegate).sendToPeer(org.mockito.kotlin.eq(nextHopPeerID), any())
+        verify(delegate, never()).broadcastPacket(any())
+    }
+
+    @Test
+    fun `last hop does not relay further`() = runTest {
+        val route = listOf(
+            hexStringToPeerBytes(myPeerID)
+        )
+        val packet = createPacket(route, finalRecipientID)
+        val routedPacket = RoutedPacket(packet, otherPeerID)
+        whenever(delegate.sendToPeer(any(), any())).thenReturn(true)
+
+        packetRelayManager.handlePacketRelay(routedPacket)
+
+        verify(delegate).sendToPeer(org.mockito.kotlin.eq(finalRecipientID), any())
+        verify(delegate, never()).broadcastPacket(any())
+    }
+    
+    @Test
+    fun `packet with empty route is broadcast`() = runTest {
+        val packet = createPacket(null)
+        val routedPacket = RoutedPacket(packet, otherPeerID)
+
+        packetRelayManager.handlePacketRelay(routedPacket)
+
+        verify(delegate, never()).sendToPeer(any(), any())
+        verify(delegate).broadcastPacket(any())
+    }
+
+    private fun hexStringToPeerBytes(hex: String): ByteArray {
+        val result = ByteArray(8)
+        var idx = 0
+        var out = 0
+        while (idx + 1 < hex.length && out < 8) {
+            val b = hex.substring(idx, idx + 2).toIntOrNull(16)?.toByte() ?: 0
+            result[out++] = b
+            idx += 2
+        }
+        return result
+    }
+}