Add requestMtuOrThrow extension function (#61)

Author: twyatt

core/src/test/java/gatt/CoroutinesGattTest.kt

@@ -325,9 +325,7 @@ class CoroutinesGattTest {
         createDispatcher().use { dispatcher ->
             val bluetoothGatt = mockk<BluetoothGatt> {
                 every { readCharacteristic(any()) } returns false
-                every<BluetoothDevice?> { device } returns mockk {
-                    every { this@mockk.toString() } returns "00:11:22:33:FF:EE"
-                }
+                every<BluetoothDevice?> { device } returns createBluetoothDevice()
             }
             val callback = GattCallback(dispatcher)
             val gatt = CoroutinesGatt(bluetoothGatt, dispatcher, callback)
@@ -373,9 +371,7 @@ class CoroutinesGattTest {
             val callback = GattCallback(dispatcher)
             val bluetoothGatt = mockk<BluetoothGatt> {
                 every { close() } returns Unit
-                every { device } returns mockk {
-                    every { this@mockk.toString() } returns "00:11:22:33:FF:EE"
-                }
+                every { device } returns createBluetoothDevice()
                 every { disconnect() } answers {
                     callback.onConnectionStateChange(this@mockk, GATT_SUCCESS, STATE_DISCONNECTING)
                     callback.onConnectionStateChange(this@mockk, GATT_SUCCESS, STATE_DISCONNECTED)
@@ -397,9 +393,7 @@ class CoroutinesGattTest {
             val callback = GattCallback(dispatcher)
             val bluetoothGatt = mockk<BluetoothGatt> {
                 every { close() } returns Unit
-                every { device } returns mockk {
-                    every { this@mockk.toString() } returns "00:11:22:33:FF:EE"
-                }
+                every { device } returns createBluetoothDevice()
                 every { disconnect() } answers {
                     callback.onConnectionStateChange(this@mockk, GATT_SUCCESS, STATE_DISCONNECTING)
                 }
@@ -425,11 +419,12 @@ class CoroutinesGattTest {
             val callback = GattCallback(dispatcher)
             val bluetoothGatt = mockk<BluetoothGatt> {
                 every { close() } returns Unit
-                every { device } returns mockk {
-                    every { this@mockk.toString() } returns "00:11:22:33:FF:EE"
-                }
+                every { device } returns createBluetoothDevice()
             }
-            val characteristic = FakeCharacteristic(testUuid, value = byteArrayOf(0xF, 0x0, 0x0, 0xD))
+            val characteristic = FakeCharacteristic(
+                testUuid,
+                value = byteArrayOf(0xF, 0x0, 0x0, 0xD)
+            )
             val gatt = CoroutinesGatt(bluetoothGatt, dispatcher, callback)
 
             val events = runBlocking {
@@ -463,9 +458,7 @@ class CoroutinesGattTest {
             val callback = GattCallback(dispatcher)
             val bluetoothGatt = mockk<BluetoothGatt> {
                 every { close() } returns Unit
-                every { device } returns mockk {
-                    every { this@mockk.toString() } returns "00:11:22:33:FF:EE"
-                }
+                every { device } returns createBluetoothDevice()
             }
             val gatt = CoroutinesGatt(bluetoothGatt, dispatcher, callback)
 
@@ -488,9 +481,7 @@ class CoroutinesGattTest {
             val callback = GattCallback(dispatcher)
             val bluetoothGatt = mockk<BluetoothGatt> {
                 every { close() } returns Unit
-                every { device } returns mockk {
-                    every { this@mockk.toString() } returns "00:11:22:33:FF:EE"
-                }
+                every { device } returns createBluetoothDevice()
                 every { readCharacteristic(any()) } answers {
                     callback.onConnectionStateChange(this@mockk, GATT_SUCCESS, STATE_DISCONNECTED)
                     true
@@ -520,9 +511,7 @@ class CoroutinesGattTest {
             val callback = GattCallback(dispatcher)
             val bluetoothGatt = mockk<BluetoothGatt> {
                 every { close() } returns Unit
-                every { device } returns mockk {
-                    every { this@mockk.toString() } returns "00:11:22:33:FF:EE"
-                }
+                every { device } returns createBluetoothDevice()
                 every { readCharacteristic(any()) } answers {
                     didReadCharacteristic.offer(Unit)
                     true
@@ -554,6 +543,10 @@ private val dispatcherNumber = AtomicInteger()
 private fun createDispatcher() =
     newSingleThreadContext("MockGatt${dispatcherNumber.incrementAndGet()}")
 
+private fun createBluetoothDevice(): BluetoothDevice = mockk {
+    every { this@mockk.toString() } returns "00:11:22:33:FF:EE"
+}
+
 private fun createCharacteristic(
     uuid: UUID = testUuid,
     data: ByteArray = byteArrayOf()

throw/src/main/java/GattOrThrow.kt

@@ -89,3 +89,15 @@ suspend fun GattIo.writeDescriptorOrThrow(
             check(status == GATT_SUCCESS) { "Descriptor write failed with status $status." }
         }
 }
+
+/**
+ * @throws [IllegalStateException] if [GattIo.requestMtu] call does not return [GATT_SUCCESS].
+ */
+suspend fun GattIo.requestMtuOrThrow(
+    mtu: Int
+): Int {
+    return requestMtu(mtu)
+        .also { (_, status) ->
+            check(status == GATT_SUCCESS) { "Request MTU of $mtu failed with status $status." }
+        }.mtu
+}

throw/src/test/java/GattTest.kt

@@ -14,10 +14,12 @@ import com.juul.able.gatt.Gatt
 import com.juul.able.gatt.OnCharacteristicRead
 import com.juul.able.gatt.OnCharacteristicWrite
 import com.juul.able.gatt.OnDescriptorWrite
+import com.juul.able.gatt.OnMtuChanged
 import com.juul.able.gatt.OnReadRemoteRssi
 import com.juul.able.throwable.discoverServicesOrThrow
 import com.juul.able.throwable.readCharacteristicOrThrow
 import com.juul.able.throwable.readRemoteRssiOrThrow
+import com.juul.able.throwable.requestMtuOrThrow
 import com.juul.able.throwable.setCharacteristicNotificationOrThrow
 import com.juul.able.throwable.writeCharacteristicOrThrow
 import com.juul.able.throwable.writeDescriptorOrThrow
@@ -171,4 +173,35 @@ class GattTest {
             }
         }
     }
+
+    @Test
+    fun `requestMtuOrThrow throws IllegalStateException for non-GATT_SUCCESS response`() {
+        val gatt = mockk<Gatt> {
+            coEvery { requestMtu(any()) } returns OnMtuChanged(
+                mtu = 23,
+                status = GATT_FAILURE
+            )
+        }
+
+        assertFailsWith<IllegalStateException> {
+            runBlocking {
+                gatt.requestMtuOrThrow(1024)
+            }
+        }
+    }
+
+    @Test
+    fun `requestMtuOrThrow returns MTU as Int for GATT_SUCCESS response`() {
+        val gatt = mockk<Gatt> {
+            coEvery { requestMtu(any()) } returns OnMtuChanged(
+                mtu = 128,
+                status = GATT_SUCCESS
+            )
+        }
+
+        assertEquals(
+            expected = 128,
+            actual = runBlocking { gatt.requestMtuOrThrow(128) }
+        )
+    }
 }