Updates snippets for Gestures and testing docs

Test: ./gradlew :compose:integration-tests:docs-snippets:ktlint
Change-Id: I7d727adc18c2485d56fbd2536b9a66e0f2568837

diff --git a/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/gestures/Gestures.kt b/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/gestures/Gestures.kt
index 6ef6d29..2b55af8 100644
--- a/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/gestures/Gestures.kt
+++ b/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/gestures/Gestures.kt

@@ -58,7 +58,6 @@
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.graphics.TileMode
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.input.pointer.consumeAllChanges
 import androidx.compose.ui.input.pointer.pointerInput
@@ -177,12 +176,12 @@
     fun ScrollableSample() {
         // actual composable state
         var offset by remember { mutableStateOf(0f) }
-        // state for Scrollable, describes how to consume scrolling delta and update offset
         Box(
             Modifier
                 .size(150.dp)
                 .scrollable(
                     orientation = Orientation.Vertical,
+                    // Scrollable state: describes how to consume scrolling delta and update offset
                     state = rememberScrollableState { delta ->
                         offset += delta
                         delta
@@ -216,9 +215,7 @@
 private object GesturesSnippet6 {
     @Composable
     fun NestedSample() {
-        val gradient = Brush.verticalGradient(
-            listOf(Color.Gray, Color.White), 0.0f, 1000.0f, TileMode.Repeated
-        )
+        val gradient = Brush.verticalGradient(0f to Color.Gray, 1000f to Color.White)
         Box(
             modifier = Modifier
                 .background(Color.LightGray)
@@ -280,19 +277,19 @@
 }
 @Composable private fun GesturesSnippet8() {
     Box(modifier = Modifier.fillMaxSize()) {
-        val offsetX = remember { mutableStateOf(0f) }
-        val offsetY = remember { mutableStateOf(0f) }
+        var offsetX by remember { mutableStateOf(0f) }
+        var offsetY by remember { mutableStateOf(0f) }
 
         Box(
             Modifier
-                .offset { IntOffset(offsetX.value.roundToInt(), offsetY.value.roundToInt()) }
+                .offset { IntOffset(offsetX.roundToInt(), offsetY.roundToInt()) }
                 .background(Color.Blue)
                 .size(50.dp)
                 .pointerInput(Unit) {
                     detectDragGestures { change, dragAmount ->
                         change.consumeAllChanges()
-                        offsetX.value = (offsetX.value + dragAmount.x)
-                        offsetY.value = (offsetY.value + dragAmount.y)
+                        offsetX += dragAmount.x
+                        offsetY += dragAmount.y
                     }
                 }
         )
@@ -314,7 +311,7 @@
 
         val swipeableState = rememberSwipeableState(0)
         val sizePx = with(LocalDensity.current) { squareSize.toPx() }
-        val anchors = mapOf(0f to 0, sizePx to 1)
+        val anchors = mapOf(0f to 0, sizePx to 1) // Maps anchor points (in px) to states
 
         Box(
             modifier = Modifier

diff --git a/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/testing/CheatSheet.kt b/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/testing/CheatSheet.kt
index 72b3300..3feae6b 100644
--- a/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/testing/CheatSheet.kt
+++ b/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/testing/CheatSheet.kt

@@ -28,6 +28,7 @@
 import androidx.compose.ui.layout.FirstBaseline
 import androidx.compose.ui.semantics.ProgressBarRangeInfo
 import androidx.compose.ui.semantics.SemanticsActions
+import androidx.compose.ui.test.IdlingResource
 import androidx.compose.ui.test.assert
 import androidx.compose.ui.test.assertAll
 import androidx.compose.ui.test.assertAny
@@ -163,6 +164,8 @@
 import androidx.compose.ui.test.width
 import androidx.compose.ui.text.input.ImeAction
 import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
 import android.view.KeyEvent as AndroidKeyEvent
 import android.view.KeyEvent.ACTION_DOWN as ActionDown
 import android.view.KeyEvent.KEYCODE_A as KeyCodeA
@@ -378,6 +381,7 @@
         runOnIdle { }
         runOnUiThread { }
         waitForIdle()
+        waitUntil { true }
         mainClock.apply {
             autoAdvance
             currentTime
@@ -385,6 +389,11 @@
             advanceTimeByFrame()
             advanceTimeUntil { true }
         }
+        registerIdlingResource(idlingResource)
+        unregisterIdlingResource(idlingResource)
+    }
+    GlobalScope.launch {
+        nonAndroidComposeTestRule.awaitIdle()
     }
 
     // ANDROID COMPOSE TEST RULE
@@ -410,4 +419,8 @@
 private val nonAndroidComposeTestRule = createComposeRule()
 private val keyEvent2 = KeyEvent(AndroidKeyEvent(ActionDown, KeyCodeA))
 private val offset = Offset(0f, 0f)
-private val rangeInfo = ProgressBarRangeInfo(0f, 0f..1f)
\ No newline at end of file
+private val rangeInfo = ProgressBarRangeInfo(0f, 0f..1f)
+private val idlingResource = object : IdlingResource {
+    override val isIdleNow: Boolean
+        get() = TODO("Stub!")
+}

diff --git a/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/testing/Testing.kt b/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/testing/Testing.kt
index f69f42d..9060916 100644
--- a/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/testing/Testing.kt
+++ b/compose/integration-tests/docs-snippets/src/main/java/androidx/compose/integration/docs/testing/Testing.kt

@@ -224,6 +224,20 @@
     composeTestRule.unregisterIdlingResource(idlingResource)
 }
 
+private fun TestingSyncSnippets5() {
+    composeTestRule.mainClock.autoAdvance = true // default
+    composeTestRule.waitForIdle() // Advances the clock until Compose is idle
+
+    composeTestRule.mainClock.autoAdvance = false
+    composeTestRule.waitForIdle() // Only waits for Idling Resources to become idle
+}
+
+private fun TestingSyncSnippets6and7() {
+    composeTestRule.mainClock.advanceTimeUntil(timeoutMs) { condition }
+
+    composeTestRule.waitUntil(timeoutMs) { condition }
+}
+
 private object TestingSemanticsSnippets1 {
     // Creates a Semantics property of type boolean
     val PickedDateKey = SemanticsPropertyKey<Long>("PickedDate")
@@ -295,7 +309,9 @@
 private lateinit var key: SemanticsPropertyKey<AccessibilityAction<() -> Boolean>>
 private var keyEvent = KeyEvent(AndroidKeyEvent(ActionDown, KeyCodeA))
 private const val milliseconds = 10L
-val idlingResource = object : IdlingResource {
+private const val timeoutMs = 10L
+private val idlingResource = object : IdlingResource {
     override val isIdleNow: Boolean
         get() = TODO("Stub!")
-}
\ No newline at end of file
+}
+private val condition = true
\ No newline at end of file