feat(sidecar): EraseText backend support on android and ios

sidecar/src/main/kotlin/dev/sanderling/sidecar/DriverBackend.kt

@@ -6,6 +6,7 @@ interface DriverBackend {
     fun tap(x: Int, y: Int)
     fun tapSelector(selector: String)
     fun inputText(text: String)
+    fun eraseText(characterCount: Int)
     fun swipe(fromX: Int, fromY: Int, toX: Int, toY: Int, durationMillis: Long)
     fun pressKey(key: String)
     fun longPress(x: Int, y: Int)
@@ -402,6 +403,16 @@ class StubDriverBackend(
         runAdb(listOf("shell", "input", "text", escapeForAdbInputText(text)))
     }
 
+    @Volatile var lastEraseCharacterCount: Int? = null
+        private set
+
+    override fun eraseText(characterCount: Int) {
+        lastEraseCharacterCount = characterCount
+        repeat(characterCount) {
+            runAdb(listOf("shell", "input", "keyevent", "KEYCODE_DEL"))
+        }
+    }
+
     @Volatile var lastSwipe: SwipeRecord? = null
         private set
     @Volatile var lastKey: String? = null
@@ -531,6 +542,8 @@ class MaestroDriverBackend(private val serial: String?) : DriverBackend {
 
     override fun inputText(text: String) = driver.inputText(text)
 
+    override fun eraseText(characterCount: Int) = driver.eraseText(characterCount)
+
     override fun swipe(fromX: Int, fromY: Int, toX: Int, toY: Int, durationMillis: Long) =
         driver.swipe(maestro.Point(fromX, fromY), maestro.Point(toX, toY), maxOf(durationMillis, 250L))
 
@@ -732,6 +745,8 @@ class IosDriverBackend(private val udid: String) : DriverBackend {
 
     override fun inputText(text: String) = withReconnect { driver.inputText(text) }
 
+    override fun eraseText(characterCount: Int) = withReconnect { driver.eraseText(characterCount) }
+
     override fun swipe(fromX: Int, fromY: Int, toX: Int, toY: Int, durationMillis: Long) = withReconnect {
         driver.swipe(maestro.Point(fromX, fromY), maestro.Point(toX, toY), maxOf(durationMillis, 250L))
     }

sidecar/src/main/kotlin/dev/sanderling/sidecar/DriverService.kt

@@ -4,6 +4,7 @@ import com.google.protobuf.ByteString
 import dev.sanderling.driver.v1.DriverGrpc
 import dev.sanderling.driver.v1.Duration
 import dev.sanderling.driver.v1.Empty
+import dev.sanderling.driver.v1.EraseTextRequest
 import dev.sanderling.driver.v1.HealthStatus
 import dev.sanderling.driver.v1.HierarchyJSON
 import dev.sanderling.driver.v1.Image
@@ -74,6 +75,13 @@ class DriverService(
         }
     }
 
+    override fun eraseText(request: EraseTextRequest, responseObserver: StreamObserver<Empty>) {
+        runRpc(responseObserver) {
+            backend.eraseText(request.characterCount)
+            Empty.getDefaultInstance()
+        }
+    }
+
     override fun swipe(request: SwipeRequest, responseObserver: StreamObserver<Empty>) {
         runRpc(responseObserver) {
             val from = request.from

sidecar/src/test/kotlin/dev/sanderling/sidecar/DriverServiceTest.kt

@@ -3,6 +3,7 @@ package dev.sanderling.sidecar
 import dev.sanderling.driver.v1.DriverGrpc
 import dev.sanderling.driver.v1.Duration
 import dev.sanderling.driver.v1.Empty
+import dev.sanderling.driver.v1.EraseTextRequest
 import dev.sanderling.driver.v1.LaunchRequest
 import dev.sanderling.driver.v1.Point
 import dev.sanderling.driver.v1.PressKeyRequest
@@ -82,6 +83,14 @@ class DriverServiceTest {
         assertEquals("hello world", backend.lastInputText)
     }
 
+    @Test fun eraseTextForwardsCharacterCount() {
+        val backend = StubDriverBackend("android")
+        val client = newClient(backend)
+
+        client.eraseText(EraseTextRequest.newBuilder().setCharacterCount(11).build())
+        assertEquals(11, backend.lastEraseCharacterCount)
+    }
+
     @Test fun screenshotReturnsBackendBytes() {
         val backend = object : DriverBackend by StubDriverBackend("android") {
             override fun screenshot(): Triple<ByteArray, Int, Int> = Triple(byteArrayOf(1, 2, 3), 1080, 2340)

sidecar/src/test/kotlin/dev/sanderling/sidecar/InputTextTest.kt

@@ -15,6 +15,18 @@ class InputTextTest {
         assertEquals(listOf(listOf("shell", "input", "text", "Emergency%sFund")), commands)
     }
 
+    @Test fun eraseTextSendsOneDeleteKeyPerCharacter() {
+        val commands = mutableListOf<List<String>>()
+        val backend = StubDriverBackend("android") { commands.add(it) }
+
+        backend.eraseText(3)
+
+        assertEquals(
+            List(3) { listOf("shell", "input", "keyevent", "KEYCODE_DEL") },
+            commands,
+        )
+    }
+
     @Test fun escapeForAdbInputTextSubstitutesSpaces() {
         assertEquals("hello%sworld", StubDriverBackend.escapeForAdbInputText("hello world"))
     }

sidecar/src/test/kotlin/dev/sanderling/sidecar/SnapshotHandlerTest.kt

@@ -60,6 +60,7 @@ class SnapshotHandlerTest {
             override fun tap(x: Int, y: Int) {}
             override fun tapSelector(selector: String) {}
             override fun inputText(text: String) {}
+            override fun eraseText(characterCount: Int) {}
             override fun swipe(fromX: Int, fromY: Int, toX: Int, toY: Int, durationMillis: Long) {}
             override fun pressKey(key: String) {}
             override fun longPress(x: Int, y: Int) {}