Add ExploreFragment Unit Tests (#4809)

app/src/test/kotlin/fr/free/nrw/commons/explore/ExploreFragmentUnitTest.kt

@@ -0,0 +1,155 @@
+package fr.free.nrw.commons.explore
+
+import android.content.Context
+import android.os.Looper.getMainLooper
+import android.view.*
+import androidx.fragment.app.FragmentManager
+import androidx.fragment.app.FragmentTransaction
+import com.google.android.material.tabs.TabLayout
+import fr.free.nrw.commons.R
+import fr.free.nrw.commons.TestAppAdapter
+import fr.free.nrw.commons.TestCommonsApplication
+import fr.free.nrw.commons.contributions.MainActivity
+import org.junit.Assert
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.Mockito.`when`
+import org.mockito.Mockito.verify
+import org.mockito.MockitoAnnotations
+import org.powermock.reflect.Whitebox
+import org.robolectric.Robolectric
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.RuntimeEnvironment
+import org.robolectric.Shadows
+import org.robolectric.annotation.Config
+import org.robolectric.annotation.LooperMode
+import org.robolectric.fakes.RoboMenu
+import org.robolectric.fakes.RoboMenuItem
+import org.wikipedia.AppAdapter
+
+@RunWith(RobolectricTestRunner::class)
+@Config(sdk = [21], application = TestCommonsApplication::class)
+@LooperMode(LooperMode.Mode.PAUSED)
+class ExploreFragmentUnitTest {
+
+    private lateinit var fragment: ExploreFragment
+    private lateinit var fragmentManager: FragmentManager
+    private lateinit var context: Context
+    private lateinit var view: View
+    private lateinit var layoutInflater: LayoutInflater
+    private lateinit var viewPager: ParentViewPager
+    private lateinit var activity: MainActivity
+
+    @Mock
+    private lateinit var tabLayout: TabLayout
+
+    @Mock
+    private lateinit var exploreRootFragment: ExploreListRootFragment
+
+    @Mock
+    private lateinit var inflater: MenuInflater
+
+    @Before
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+        context = RuntimeEnvironment.application.applicationContext
+
+        AppAdapter.set(TestAppAdapter())
+
+        activity = Robolectric.buildActivity(MainActivity::class.java).create().get()
+        fragment = ExploreFragment()
+        fragmentManager = activity.supportFragmentManager
+        val fragmentTransaction: FragmentTransaction = fragmentManager.beginTransaction()
+        fragmentTransaction.add(fragment, null)
+        fragmentTransaction.commitNowAllowingStateLoss()
+
+        layoutInflater = LayoutInflater.from(activity)
+        view = fragment.onCreateView(layoutInflater, null, null) as View
+        viewPager = view.findViewById(R.id.viewPager)
+
+        Whitebox.setInternalState(fragment, "viewPager", viewPager)
+        Whitebox.setInternalState(fragment, "tabLayout", tabLayout)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun checkFragmentNotNull() {
+        Assert.assertNotNull(fragment)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun testSetScrollCaseTrue() {
+        fragment.setScroll(true)
+        Assert.assertEquals(viewPager.isCanScroll, true)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun testSetScrollCaseFalse() {
+        fragment.setScroll(false)
+        Assert.assertEquals(viewPager.isCanScroll, false)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun testOnBackPressedCaseTrueSelectedTabZero() {
+        Whitebox.setInternalState(fragment, "featuredRootFragment", exploreRootFragment)
+        `when`(tabLayout.selectedTabPosition).thenReturn(0)
+        `when`(exploreRootFragment.backPressed()).thenReturn(true)
+        Assert.assertEquals(fragment.onBackPressed(), true)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun testOnBackPressedCaseTrueSelectedTabNonZero() {
+        Whitebox.setInternalState(fragment, "mobileRootFragment", exploreRootFragment)
+        `when`(tabLayout.selectedTabPosition).thenReturn(1)
+        `when`(exploreRootFragment.backPressed()).thenReturn(true)
+        Assert.assertEquals(fragment.onBackPressed(), true)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun testOnBackPressedCaseFalseSelectedTabZero() {
+        Whitebox.setInternalState(fragment, "featuredRootFragment", exploreRootFragment)
+        `when`(tabLayout.selectedTabPosition).thenReturn(0)
+        `when`(exploreRootFragment.backPressed()).thenReturn(false)
+        Assert.assertEquals(fragment.onBackPressed(), false)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun testOnBackPressedCaseFalseSelectedTabNonZero() {
+        Whitebox.setInternalState(fragment, "mobileRootFragment", exploreRootFragment)
+        `when`(tabLayout.selectedTabPosition).thenReturn(1)
+        `when`(exploreRootFragment.backPressed()).thenReturn(false)
+        Assert.assertEquals(fragment.onBackPressed(), false)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun testOnOptionsItemSelectedCaseTrue() {
+        val menuItem: MenuItem = RoboMenuItem(R.id.action_search)
+        Assert.assertEquals(fragment.onOptionsItemSelected(menuItem), true)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun testOnOptionsItemSelectedCaseDefault() {
+        val menuItem: MenuItem = RoboMenuItem(android.R.id.home)
+        Assert.assertEquals(fragment.onOptionsItemSelected(menuItem), false)
+    }
+
+    @Test
+    @Throws(Exception::class)
+    fun testOnCreateOptionsMenu() {
+        Shadows.shadowOf(getMainLooper()).idle()
+        val menu: Menu = RoboMenu(context)
+        fragment.onCreateOptionsMenu(menu, inflater)
+        verify(inflater).inflate(R.menu.menu_search, menu)
+    }
+
+}