From 6be39aebde2ac64c703358f3c88eb3f4c9d29f19 Mon Sep 17 00:00:00 2001
From: Tiger Oakes <toakes@mozilla.com>
Date: Wed, 15 Jul 2020 23:31:59 -0700
Subject: [PATCH] Add tests for StartupReportFullyDrawn (#12560)

---
 .../fenix/perf/StartupReportFullyDrawn.kt     |  6 +-
 .../fenix/perf/StartupReportFullyDrawnTest.kt | 83 +++++++++++++++++++
 2 files changed, 86 insertions(+), 3 deletions(-)
 create mode 100644 app/src/test/java/org/mozilla/fenix/perf/StartupReportFullyDrawnTest.kt

diff --git a/app/src/main/java/org/mozilla/fenix/perf/StartupReportFullyDrawn.kt b/app/src/main/java/org/mozilla/fenix/perf/StartupReportFullyDrawn.kt
index 695359e2c..c30720fec 100644
--- a/app/src/main/java/org/mozilla/fenix/perf/StartupReportFullyDrawn.kt
+++ b/app/src/main/java/org/mozilla/fenix/perf/StartupReportFullyDrawn.kt
@@ -7,8 +7,8 @@ package org.mozilla.fenix.perf
 import android.app.Activity
 import android.view.View
 import androidx.core.view.doOnPreDraw
-import kotlinx.android.synthetic.main.activity_home.*
 import org.mozilla.fenix.HomeActivity
+import org.mozilla.fenix.R
 import org.mozilla.fenix.ext.reportFullyDrawnSafe
 import org.mozilla.fenix.home.sessioncontrol.viewholders.topsites.TopSiteItemViewHolder
 import org.mozilla.fenix.perf.StartupTimelineStateMachine.StartupDestination.APP_LINK
@@ -36,7 +36,7 @@ class StartupReportFullyDrawn {
                 state is StartupState.Cold && state.destination == APP_LINK) {
             // Instrumenting the first frame drawn should be good enough for app link for now.
             isInstrumented = true
-            attachReportFullyDrawn(activity, activity.rootContainer)
+            attachReportFullyDrawn(activity, activity.findViewById(R.id.rootContainer))
         }
     }
 
@@ -59,7 +59,7 @@ class StartupReportFullyDrawn {
         }
     }
 
-    private fun attachReportFullyDrawn(activity: HomeActivity, view: View) {
+    private fun attachReportFullyDrawn(activity: Activity, view: View) {
         // For greater accuracy, we could add an onDrawListener instead of a preDrawListener but:
         // - single use onDrawListeners are not built-in and it's non-trivial to write one
         // - the difference in timing is minimal (< 7ms on Pixel 2)
diff --git a/app/src/test/java/org/mozilla/fenix/perf/StartupReportFullyDrawnTest.kt b/app/src/test/java/org/mozilla/fenix/perf/StartupReportFullyDrawnTest.kt
new file mode 100644
index 000000000..23b67713d
--- /dev/null
+++ b/app/src/test/java/org/mozilla/fenix/perf/StartupReportFullyDrawnTest.kt
@@ -0,0 +1,83 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.perf
+
+import android.view.View
+import android.view.ViewTreeObserver
+import android.widget.LinearLayout
+import io.mockk.Called
+import io.mockk.MockKAnnotations
+import io.mockk.Runs
+import io.mockk.every
+import io.mockk.impl.annotations.MockK
+import io.mockk.just
+import io.mockk.mockk
+import io.mockk.slot
+import io.mockk.verify
+import kotlinx.android.synthetic.main.top_site_item.view.*
+import org.junit.Before
+import org.junit.Test
+import org.mozilla.fenix.HomeActivity
+import org.mozilla.fenix.R
+import org.mozilla.fenix.home.sessioncontrol.viewholders.topsites.TopSiteItemViewHolder
+import org.mozilla.fenix.perf.StartupTimelineStateMachine.StartupDestination
+import org.mozilla.fenix.perf.StartupTimelineStateMachine.StartupState
+
+class StartupReportFullyDrawnTest {
+
+    @MockK private lateinit var activity: HomeActivity
+    private lateinit var holder: TopSiteItemViewHolder
+    @MockK(relaxed = true) private lateinit var rootContainer: LinearLayout
+    @MockK(relaxed = true) private lateinit var holderItemView: View
+    @MockK(relaxed = true) private lateinit var viewTreeObserver: ViewTreeObserver
+    private lateinit var fullyDrawn: StartupReportFullyDrawn
+
+    @Before
+    fun setup() {
+        MockKAnnotations.init(this)
+        every { activity.findViewById<LinearLayout>(R.id.rootContainer) } returns rootContainer
+        every { holderItemView.context } returns activity
+        every { holderItemView.top_site_item } returns mockk(relaxed = true)
+        holder = TopSiteItemViewHolder(holderItemView, mockk())
+        every { rootContainer.viewTreeObserver } returns viewTreeObserver
+        every { holderItemView.viewTreeObserver } returns viewTreeObserver
+
+        fullyDrawn = StartupReportFullyDrawn()
+    }
+
+    @Test
+    fun testOnActivityCreateEndHome() {
+        // Only APP_LINK destination
+        fullyDrawn.onActivityCreateEndHome(StartupState.Cold(StartupDestination.UNKNOWN), activity)
+        fullyDrawn.onActivityCreateEndHome(StartupState.Cold(StartupDestination.HOMESCREEN), activity)
+        verify { activity wasNot Called }
+
+        // Only run once
+        fullyDrawn.onActivityCreateEndHome(StartupState.Cold(StartupDestination.APP_LINK), activity)
+        verify(exactly = 1) { activity.findViewById<LinearLayout>(R.id.rootContainer) }
+
+        fullyDrawn.onActivityCreateEndHome(StartupState.Cold(StartupDestination.APP_LINK), activity)
+        verify(exactly = 1) { activity.findViewById<LinearLayout>(R.id.rootContainer) }
+
+        every { activity.reportFullyDrawn() } just Runs
+        triggerPreDraw()
+        verify { activity.reportFullyDrawn() }
+    }
+
+    @Test
+    fun testOnTopSitesItemBound() {
+        fullyDrawn.onTopSitesItemBound(StartupState.Cold(StartupDestination.HOMESCREEN), holder)
+
+        every { activity.reportFullyDrawn() } just Runs
+        triggerPreDraw()
+        verify { activity.reportFullyDrawn() }
+    }
+
+    private fun triggerPreDraw() {
+        val listener = slot<ViewTreeObserver.OnPreDrawListener>()
+        verify { viewTreeObserver.addOnPreDrawListener(capture(listener)) }
+        listener.captured.onPreDraw()
+    }
+}