issue#103 Removing item animations

app/src/sharedTest/java/org/fnives/test/showcase/ui/home/HomeRobot.kt

@@ -21,6 +21,7 @@ import androidx.test.espresso.matcher.ViewMatchers.withText
 import org.fnives.test.showcase.R
 import org.fnives.test.showcase.android.testutil.intent.notIntended
 import org.fnives.test.showcase.android.testutil.viewaction.imageview.WithDrawable
+import org.fnives.test.showcase.android.testutil.viewaction.recycler.RemoveItemAnimations
 import org.fnives.test.showcase.android.testutil.viewaction.swiperefresh.PullToRefresh
 import org.fnives.test.showcase.model.content.Content
 import org.fnives.test.showcase.model.content.FavouriteContent
@@ -29,6 +30,16 @@ import org.hamcrest.Matchers.allOf
 
 class HomeRobot {
 
+    /**
+     * Needed because Espresso idling sometimes not in sync with RecyclerView's animation.
+     * So we simply remove the item animations, the animations should be disabled anyway for test.
+     *
+     * Reference: https://github.com/android/android-test/issues/223
+     */
+    fun removeItemAnimations() = apply {
+        Espresso.onView(withId(R.id.recycler)).perform(RemoveItemAnimations())
+    }
+
     fun setupIntentResults() {
         Intents.intending(IntentMatchers.hasComponent(AuthActivity::class.java.canonicalName))
             .respondWith(Instrumentation.ActivityResult(Activity.RESULT_OK, Intent()))
@@ -50,6 +61,7 @@ class HomeRobot {
     }
 
     fun assertContainsItem(index: Int, item: FavouriteContent) = apply {
+        removeItemAnimations()
         val isFavouriteResourceId = if (item.isFavourite) {
             R.drawable.favorite_24
         } else {
@@ -69,6 +81,7 @@ class HomeRobot {
     }
 
     fun clickOnContentItem(index: Int, item: Content) = apply {
+        removeItemAnimations()
         Espresso.onView(withId(R.id.recycler))
             .perform(RecyclerViewActions.scrollToPosition<RecyclerView.ViewHolder>(index))
 
@@ -91,6 +104,7 @@ class HomeRobot {
     }
 
     fun assertContainsNoItems() = apply {
+        removeItemAnimations()
         Espresso.onView(withId(R.id.recycler))
             .check(matches(hasChildCount(0)))
     }

test-util-android/src/main/java/org/fnives/test/showcase/android/testutil/viewaction/recycler/RemoveItemAnimations.kt

@@ -0,0 +1,25 @@
+package org.fnives.test.showcase.android.testutil.viewaction.recycler
+
+import android.view.View
+import androidx.recyclerview.widget.RecyclerView
+import androidx.test.espresso.UiController
+import androidx.test.espresso.ViewAction
+import androidx.test.espresso.matcher.ViewMatchers
+import org.hamcrest.Matcher
+
+/**
+ * Sets the [RecyclerView]'s [itemAnimator][RecyclerView.setItemAnimator] to null, thus disabling animations.
+ */
+class RemoveItemAnimations : ViewAction {
+    override fun getConstraints(): Matcher<View> =
+        ViewMatchers.isAssignableFrom(RecyclerView::class.java)
+
+    override fun getDescription(): String =
+        "Remove item animations"
+
+    override fun perform(uiController: UiController, view: View) {
+        val recycler: RecyclerView = view as RecyclerView
+        recycler.itemAnimator = null
+        uiController.loopMainThreadUntilIdle()
+    }
+}