[fenix] For https://github.com/mozilla-mobile/fenix/issues/18421 re-enable verifyContextOpenImageNewTab, verifyContextOpenLinkNewTab & verifyContextOpenLinkPrivateTab UI tests

app/src/androidTest/java/org/mozilla/fenix/ui/ContextMenusTest.kt

@@ -9,7 +9,6 @@ import androidx.test.uiautomator.UiDevice
 import okhttp3.mockwebserver.MockWebServer
 import org.junit.After
 import org.junit.Before
-import org.junit.Ignore
 import org.junit.Rule
 import org.junit.Test
 import org.mozilla.fenix.ext.settings
@@ -54,7 +53,6 @@ class ContextMenusTest {
         mockWebServer.shutdown()
     }
 
-    @Ignore("Test failures: https://github.com/mozilla-mobile/fenix/issues/18421")
     @Test
     fun verifyContextOpenLinkNewTab() {
         val pageLinks =
@@ -69,7 +67,7 @@ class ContextMenusTest {
             verifyLinkContextMenuItems(genericURL.url)
             clickContextOpenLinkInNewTab()
             verifySnackBarText("New tab opened")
-            snackBarButtonClick("Switch")
+            snackBarButtonClick()
             verifyUrl(genericURL.url.toString())
         }.openTabDrawer {
             verifyNormalModeSelected()
@@ -78,7 +76,6 @@ class ContextMenusTest {
         }
     }
 
-    @Ignore("Test failures: https://github.com/mozilla-mobile/fenix/issues/18421")
     @Test
     fun verifyContextOpenLinkPrivateTab() {
         val pageLinks =
@@ -93,7 +90,7 @@ class ContextMenusTest {
             verifyLinkContextMenuItems(genericURL.url)
             clickContextOpenLinkInPrivateTab()
             verifySnackBarText("New private tab opened")
-            snackBarButtonClick("Switch")
+            snackBarButtonClick()
             verifyUrl(genericURL.url.toString())
         }.openTabDrawer {
             verifyPrivateModeSelected()
@@ -137,7 +134,6 @@ class ContextMenusTest {
         }
     }
 
-    @Ignore("Intermittent: https://github.com/mozilla-mobile/fenix/issues/12367")
     @Test
     fun verifyContextOpenImageNewTab() {
         val pageLinks =
@@ -152,7 +148,7 @@ class ContextMenusTest {
             verifyLinkImageContextMenuItems(imageResource.url)
             clickContextOpenImageNewTab()
             verifySnackBarText("New tab opened")
-            snackBarButtonClick("Switch")
+            snackBarButtonClick()
             verifyUrl(imageResource.url.toString())
         }
     }

app/src/androidTest/java/org/mozilla/fenix/ui/robots/BrowserRobot.kt

@@ -20,7 +20,6 @@ import androidx.test.espresso.intent.matcher.IntentMatchers
 import androidx.test.espresso.matcher.RootMatchers.isDialog
 import androidx.test.espresso.matcher.ViewMatchers
 import androidx.test.espresso.matcher.ViewMatchers.Visibility
-import androidx.test.espresso.matcher.ViewMatchers.isCompletelyDisplayed
 import androidx.test.espresso.matcher.ViewMatchers.isDisplayed
 import androidx.test.espresso.matcher.ViewMatchers.withContentDescription
 import androidx.test.espresso.matcher.ViewMatchers.withEffectiveVisibility
@@ -45,6 +44,7 @@ import org.mozilla.fenix.helpers.Constants.LONG_CLICK_DURATION
 import org.mozilla.fenix.helpers.SessionLoadedIdlingResource
 import org.mozilla.fenix.helpers.TestAssetHelper.waitingTime
 import org.mozilla.fenix.helpers.TestHelper.packageName
+import org.mozilla.fenix.helpers.TestHelper.waitForObjects
 import org.mozilla.fenix.helpers.click
 import org.mozilla.fenix.helpers.ext.waitNotNull
 
@@ -112,11 +112,13 @@ class BrowserRobot {
     }
 
     fun verifySnackBarText(expectedText: String) {
-        val mDevice = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation())
-        mDevice.waitNotNull(Until.findObject(text(expectedText)), waitingTime)
+        mDevice.waitForObjects(mDevice.findObject(UiSelector().textContains(expectedText)))
 
-        onView(withText(expectedText)).check(
-            matches(isCompletelyDisplayed())
+        assertTrue(
+            mDevice.findObject(
+                UiSelector()
+                    .textContains(expectedText)
+            ).waitForExists(waitingTime)
         )
     }
 
@@ -401,10 +403,14 @@ class BrowserRobot {
         }
     }
 
-    fun snackBarButtonClick(expectedText: String) {
-        onView(allOf(withId(R.id.snackbar_btn), withText(expectedText))).check(
-            matches(withEffectiveVisibility(ViewMatchers.Visibility.VISIBLE))
-        ).perform(ViewActions.click())
+    fun snackBarButtonClick() {
+        val switchButton =
+            mDevice.findObject(
+                UiSelector()
+                    .resourceId("$packageName:id/snackbar_btn")
+            )
+        switchButton.waitForExists(waitingTime)
+        switchButton.clickAndWaitForNewWindow(waitingTime)
     }
 
     fun verifySaveLoginPromptIsShown() {