[fenix] Bug 1814506 - Add unit tests to cover multi selection of tabs

Three new unit tests have been added to cover cases when
multiple tabs are selected or unselected.

app/src/test/java/org/mozilla/fenix/tabstray/DefaultTabsTrayControllerTest.kt

@@ -54,6 +54,7 @@ import org.mozilla.fenix.ext.maxActiveTime
 import org.mozilla.fenix.ext.potentialInactiveTabs
 import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
 import org.mozilla.fenix.home.HomeFragment
+import org.mozilla.fenix.selection.SelectionHolder
 import org.mozilla.fenix.utils.Settings
 import java.util.concurrent.TimeUnit
 
@@ -543,6 +544,91 @@ class DefaultTabsTrayControllerTest {
         }
     }
 
+    @Test
+    fun `GIVEN no tabs selected and the user is not in multi select mode WHEN the user long taps a tab THEN that tab will become selected`() {
+        trayStore = TabsTrayStore()
+        val selectionHolder: SelectionHolder<TabSessionState> = mockk {
+            every { selectedItems } returns emptySet()
+        }
+        val controller = spyk(createController())
+        val tab1 = TabSessionState(
+            id = "1",
+            content = ContentState(
+                url = "www.mozilla.com",
+            ),
+        )
+        val tab2 = TabSessionState(
+            id = "2",
+            content = ContentState(
+                url = "www.google.com",
+            ),
+        )
+        trayStore.dispatch(TabsTrayAction.ExitSelectMode)
+        trayStore.waitUntilIdle()
+
+        controller.handleMultiSelectClicked(tab1, selectionHolder, "Tabs tray")
+        verify(exactly = 1) { controller.handleTabSelected(tab1, "Tabs tray") }
+
+        controller.handleMultiSelectClicked(tab2, selectionHolder, "Tabs tray")
+        verify(exactly = 1) { controller.handleTabSelected(tab2, "Tabs tray") }
+    }
+
+    @Test
+    fun `GIVEN the user is in multi select mode and a tab is selected WHEN the user taps the selected tab THEN the tab will become unselected`() {
+        trayStore = TabsTrayStore()
+        val tab1 = TabSessionState(
+            id = "1",
+            content = ContentState(
+                url = "www.mozilla.com",
+            ),
+        )
+        val tab2 = TabSessionState(
+            id = "2",
+            content = ContentState(
+                url = "www.google.com",
+            ),
+        )
+        val selectionHolder: SelectionHolder<TabSessionState> = mockk {
+            every { selectedItems } returns setOf(tab1, tab2)
+        }
+        val controller = spyk(createController())
+        trayStore.dispatch(TabsTrayAction.EnterSelectMode)
+        trayStore.waitUntilIdle()
+
+        controller.handleMultiSelectClicked(tab1, selectionHolder, "Tabs tray")
+        verify(exactly = 1) { controller.handleTabUnselected(tab1) }
+
+        controller.handleMultiSelectClicked(tab2, selectionHolder, "Tabs tray")
+        verify(exactly = 1) { controller.handleTabUnselected(tab2) }
+    }
+
+    @Test
+    fun `GIVEN at least a tab is selected and the user is in multi select mode WHEN the user taps a tab THEN that tab will become selected`() {
+        trayStore = spyk(TabsTrayStore())
+        trayStore.dispatch(TabsTrayAction.EnterSelectMode)
+        trayStore.waitUntilIdle()
+        val controller = spyk(createController())
+        val tab1 = TabSessionState(
+            id = "1",
+            content = ContentState(
+                url = "www.mozilla.com",
+            ),
+        )
+        val selectionHolder: SelectionHolder<TabSessionState> = mockk {
+            every { selectedItems } returns setOf(tab1)
+        }
+        val tab2 = TabSessionState(
+            id = "2",
+            content = ContentState(
+                url = "www.google.com",
+            ),
+        )
+
+        controller.handleMultiSelectClicked(tab2, selectionHolder, "Tabs tray")
+
+        verify(exactly = 1) { trayStore.dispatch(TabsTrayAction.AddSelectTab(tab2)) }
+    }
+
     @Test
     fun `GIVEN the user selects only the current tab WHEN the user forces tab to be inactive THEN tab does not become inactive`() {
         val currentTab = TabSessionState(content = mockk(), id = "currentTab", createdAt = 11)