test(network): Add Kotest property-based tests for StreamFrameCodec

core/network/build.gradle.kts

@@ -67,6 +67,10 @@ kotlin {
             implementation(libs.okhttp3.logging.interceptor)
         }
 
-        commonTest.dependencies { implementation(libs.kotlinx.coroutines.test) }
+        commonTest.dependencies {
+            implementation(libs.kotlinx.coroutines.test)
+            implementation(libs.kotest.assertions)
+            implementation(libs.kotest.property)
+        }
     }
 }

core/network/src/commonTest/kotlin/org/meshtastic/core/network/transport/StreamFrameCodecTest.kt

@@ -16,6 +16,14 @@
  */
 package org.meshtastic.core.network.transport
 
+import io.kotest.matchers.nulls.shouldNotBeNull
+import io.kotest.matchers.shouldBe
+import io.kotest.property.Arb
+import io.kotest.property.arbitrary.byte
+import io.kotest.property.arbitrary.byteArray
+import io.kotest.property.arbitrary.int
+import io.kotest.property.checkAll
+import kotlinx.coroutines.test.runTest
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertTrue
@@ -56,6 +64,33 @@ class StreamFrameCodecTest {
         assertEquals(listOf(0x55.toByte()), receivedPackets[0].toList())
     }
 
+    @Test
+    fun `frameAndSend and processInputByte are inverse`() = runTest {
+        checkAll(Arb.byteArray(Arb.int(0, 512), Arb.byte())) { payload ->
+            var received: ByteArray? = null
+            val codec = StreamFrameCodec(onPacketReceived = { received = it })
+            
+            val bytes = mutableListOf<ByteArray>()
+            codec.frameAndSend(payload, sendBytes = { bytes.add(it) })
+            
+            bytes.forEach { arr ->
+                arr.forEach { codec.processInputByte(it) }
+            }
+            
+            received.shouldNotBeNull()
+            received.shouldBe(payload)
+        }
+    }
+
+    @Test
+    fun `processInputByte is robust against random noise`() = runTest {
+        checkAll(Arb.byteArray(Arb.int(0, 1000), Arb.byte())) { noise ->
+            val codec = StreamFrameCodec(onPacketReceived = { /* ignore */ })
+            noise.forEach { codec.processInputByte(it) }
+            // Should not crash
+        }
+    }
+
     @Test
     fun `processInputByte handles multiple packets sequentially`() {
         val packet1 = byteArrayOf(0x94.toByte(), 0xc3.toByte(), 0x00, 0x01, 0x11)