Add test for BottomNavigationLayout

Signed-off-by: Aditya Wasan <adityawasan55@gmail.com>

app/src/androidTest/java/dev/msfjarvis/lobsters/BottomNavigationLayoutTest.kt

@@ -0,0 +1,115 @@
+package dev.msfjarvis.lobsters
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.test.assertContentDescriptionEquals
+import androidx.compose.ui.test.assertCountEquals
+import androidx.compose.ui.test.assertHasClickAction
+import androidx.compose.ui.test.assertIsDisplayed
+import androidx.compose.ui.test.assertIsNotSelected
+import androidx.compose.ui.test.assertIsSelected
+import androidx.compose.ui.test.assertTextEquals
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onChildAt
+import androidx.compose.ui.test.onChildren
+import androidx.compose.ui.test.onNodeWithTag
+import androidx.compose.ui.test.performClick
+import dev.msfjarvis.lobsters.ui.main.LobstersBottomNav
+import dev.msfjarvis.lobsters.ui.navigation.Destination
+import dev.msfjarvis.lobsters.ui.theme.LobstersTheme
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+
+
+class BottomNavigationLayoutTest {
+
+  @get:Rule
+  val composeTestRule = createComposeRule()
+
+  @Before
+  fun setUp() {
+    composeTestRule.setContent {
+      LobstersTheme {
+        var mutableDestination by remember { mutableStateOf(Destination.startDestination) }
+
+        LobstersBottomNav(
+          currentDestination = mutableDestination,
+          navigateToDestination = { mutableDestination = it },
+          jumpToIndex = {}
+        )
+      }
+    }
+  }
+
+  @Test
+  fun bottomNavItemCountTest() {
+    // Test to make sure total items are equal to enum objects present in Destination
+    composeTestRule.onNodeWithTag("LobstersBottomNav")
+      .assertExists()
+      .assertIsDisplayed()
+      .onChildren()
+      .assertCountEquals(Destination.values().size)
+  }
+
+  @Test
+  fun bottomNavItemTest() {
+    // Check hottest BottomNavItem is rendered correctly
+    composeTestRule.onNodeWithTag("LobstersBottomNav")
+      .assertExists()
+      .assertIsDisplayed()
+      .onChildAt(0)
+      .assertTextEquals("Hottest")
+      .assertContentDescriptionEquals("Hottest")
+      .assertHasClickAction()
+
+    // Check saved BottomNavItem is rendered correctly
+    composeTestRule.onNodeWithTag("LobstersBottomNav")
+      .assertExists()
+      .assertIsDisplayed()
+      .onChildAt(1)
+      .assertTextEquals("Saved")
+      .assertContentDescriptionEquals("Saved")
+      .assertHasClickAction()
+  }
+
+  @Test
+  fun bottomNavItemSelectedTest() {
+    // Check hottest BottomNav item is selected
+    composeTestRule.onNodeWithTag("LobstersBottomNav")
+      .assertExists()
+      .assertIsDisplayed()
+      .onChildAt(0)
+      .assertIsSelected()
+      .assertTextEquals("Hottest")
+
+    // Check saved BottomNav item is not selected
+    composeTestRule.onNodeWithTag("LobstersBottomNav")
+      .assertExists()
+      .assertIsDisplayed()
+      .onChildAt(1)
+      .assertIsNotSelected()
+
+    // Select the saved BottomNav item
+    composeTestRule.onNodeWithTag("LobstersBottomNav")
+      .onChildAt(1)
+      .performClick()
+
+    // Check hottest BottomNav item is not selected
+    composeTestRule.onNodeWithTag("LobstersBottomNav")
+      .assertExists()
+      .assertIsDisplayed()
+      .onChildAt(0)
+      .assertIsNotSelected()
+
+    // Check saved BottomNav item is selected
+    composeTestRule.onNodeWithTag("LobstersBottomNav")
+      .assertExists()
+      .assertIsDisplayed()
+      .onChildAt(1)
+      .assertIsSelected()
+      .assertTextEquals("Saved")
+  }
+}

app/src/main/java/dev/msfjarvis/lobsters/ui/main/MainActivity.kt

@@ -4,7 +4,6 @@ import android.os.Bundle
 import androidx.activity.compose.setContent
 import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material.BottomNavigation
 import androidx.compose.material.BottomNavigationItem
@@ -16,6 +15,7 @@ import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.res.stringResource
 import androidx.lifecycle.viewmodel.compose.viewModel
 import androidx.navigation.compose.KEY_ROUTE
@@ -35,7 +35,6 @@ import dev.msfjarvis.lobsters.ui.urllauncher.UrlLauncher
 import dev.msfjarvis.lobsters.ui.viewmodel.LobstersViewModel
 import dev.msfjarvis.lobsters.util.IconResource
 import javax.inject.Inject
-import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 
 @AndroidEntryPoint
@@ -73,14 +72,18 @@ fun LobstersApp() {
       popUpTo(navController.graph.startDestination) { inclusive = false }
     }
   }
+  val jumpToIndex: (Int) -> Unit = {
+    coroutineScope.launch {
+      hottestPostsListState.snapToItemIndex(it)
+    }
+  }
 
   Scaffold(
     bottomBar = {
       LobstersBottomNav(
-        hottestPostsListState,
-        coroutineScope,
         currentDestination,
         navigateToDestination,
+        jumpToIndex,
       )
     },
   ) { innerPadding ->
@@ -107,12 +110,11 @@ fun LobstersApp() {
 
 @Composable
 fun LobstersBottomNav(
-  hottestPostsListState: LazyListState,
-  coroutineScope: CoroutineScope,
   currentDestination: Destination,
   navigateToDestination: (destination: Destination) -> Unit,
+  jumpToIndex: (index: Int) -> Unit,
 ) {
-  BottomNavigation {
+  BottomNavigation(modifier = Modifier.testTag("LobstersBottomNav")) {
     Destination.values().forEach { screen ->
       BottomNavigationItem(
         icon = {
@@ -128,9 +130,7 @@ fun LobstersBottomNav(
           if (screen != currentDestination) {
             navigateToDestination(screen)
           } else if (screen.route == Destination.Hottest.route) {
-            coroutineScope.launch {
+            jumpToIndex(0)
-              hottestPostsListState.snapToItemIndex(0)
-            }
           }
         }
       )