fix: display "No images available" message and improve loading indicator handling in FeedScreen

app/src/androidTest/java/com/github/lookupgroup27/lookup/TestLocationProvider.kt

@@ -0,0 +1,20 @@
+package com.github.lookupgroup27.lookup
+
+import android.location.Location
+import androidx.test.core.app.ApplicationProvider
+import com.github.lookupgroup27.lookup.model.location.LocationProvider
+
+/** TestLocationProvider allows for manual setting of location values. */
+class TestLocationProvider : LocationProvider(ApplicationProvider.getApplicationContext()) {
+  fun setLocation(latitude: Double?, longitude: Double?) {
+    if (latitude != null && longitude != null) {
+      currentLocation.value =
+          Location("test").apply {
+            this.latitude = latitude
+            this.longitude = longitude
+          }
+    } else {
+      currentLocation.value = null
+    }
+  }
+}

app/src/androidTest/java/com/github/lookupgroup27/lookup/ui/feed/FeedScreenTest.kt

@@ -11,7 +11,9 @@ import androidx.compose.ui.test.performClick
 import androidx.compose.ui.test.performScrollTo
 import androidx.test.core.app.ApplicationProvider
 import androidx.test.rule.GrantPermissionRule
+import com.github.lookupgroup27.lookup.TestLocationProvider
 import com.github.lookupgroup27.lookup.model.location.LocationProvider
+import com.github.lookupgroup27.lookup.model.location.LocationProviderSingleton
 import com.github.lookupgroup27.lookup.model.post.Post
 import com.github.lookupgroup27.lookup.model.post.PostsRepository
 import com.github.lookupgroup27.lookup.model.profile.ProfileRepository
@@ -22,6 +24,8 @@ import com.github.lookupgroup27.lookup.ui.navigation.TopLevelDestinations
 import com.github.lookupgroup27.lookup.ui.post.PostsViewModel
 import com.github.lookupgroup27.lookup.ui.profile.ProfileViewModel
 import com.google.firebase.auth.FirebaseAuth
+import io.mockk.every
+import io.mockk.mockkObject
 import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
@@ -138,18 +142,30 @@ class FeedScreenTest {
     `when`(navigationActions.currentRoute()).thenReturn(Screen.FEED)
 
     locationProvider = LocationProvider(context, mutableStateOf(null))
+  }
 
+  /**
+   * Helper function to set up the FeedScreen with the given list of nearby posts.
+   *
+   * @param initialNearbyPosts The list of posts to display initially on the feed screen.
+   *
+   * This function simplifies test setup by allowing each test to specify the initial state of the
+   * feed. It handles the rendering of the FeedScreen with the specified posts and ensures a
+   * consistent setup across all tests.
+   */
+  private fun setFeedScreenContent(initialNearbyPosts: List<Post>) {
     composeTestRule.setContent {
       FeedScreen(
           postsViewModel = postsViewModel,
           navigationActions = navigationActions,
           profileViewModel = profileViewModel,
-          initialNearbyPosts = testPosts)
+          initialNearbyPosts = initialNearbyPosts)
     }
   }
 
   @Test
   fun testFeedScreenDisplaysNearbyPosts() {
+    setFeedScreenContent(testPosts)
 
     // Assert each post item is displayed
     composeTestRule.onNodeWithTag("PostItem_2").assertExists()
@@ -163,12 +179,14 @@ class FeedScreenTest {
 
   @Test
   fun testFeedExcludesLoggedInUserPosts() {
+    setFeedScreenContent(testPosts)
     // Assert that the post by the logged-in user  is not displayed
     composeTestRule.onNodeWithTag("PostItem_1").assertDoesNotExist()
   }
 
   @Test
   fun testBottomNavigationMenuIsDisplayed() {
+    setFeedScreenContent(testPosts)
 
     // Verify the bottom navigation menu is displayed
     composeTestRule
@@ -179,6 +197,7 @@ class FeedScreenTest {
 
   @Test
   fun testStarClickDisplaysAverageRating() {
+    setFeedScreenContent(testPosts)
     // Perform click on the first star icon of a post with uid "1"
     composeTestRule
         .onNodeWithTag("Star_2_2")
@@ -191,6 +210,7 @@ class FeedScreenTest {
 
   @Test
   fun testStarClickCallsUpdatePost() {
+    setFeedScreenContent(testPosts)
     // Perform click on the first star of post with uid "1"
     composeTestRule.onNodeWithTag("Star_2_2").performClick()
     postsViewModel.updatePost(testPost)
@@ -211,6 +231,7 @@ class FeedScreenTest {
 
   @Test
   fun testNavigationToFeedBlockedForLoggedOutUser() {
+    setFeedScreenContent(testPosts)
     // Mock the user as not logged in
     mockAuth = org.mockito.kotlin.mock()
     whenever(mockAuth.currentUser).thenReturn(null)
@@ -224,15 +245,74 @@ class FeedScreenTest {
 
   @Test
   fun testAddressIsDisplayed() {
+    setFeedScreenContent(testPosts)
     // Verify that the address is displayed for each post
     composeTestRule.onNodeWithTag("AddressTag_2").performScrollTo().assertIsDisplayed()
     composeTestRule.onNodeWithTag("AddressTag_5").assertDoesNotExist()
   }
 
   @Test
   fun testDescriptionIsDisplayed() {
+    setFeedScreenContent(testPosts)
     // Verify that the description is displayed for each post
     composeTestRule.onNodeWithTag("DescriptionTag_2").performScrollTo().assertIsDisplayed()
     composeTestRule.onNodeWithTag("DescriptionTag_5").assertDoesNotExist()
   }
+
+  @Test
+  fun testFeedDisplaysNoImagesMessageWhenPostsAreEmpty() {
+    // Arrange: Mock location provider and permissions
+    val testLocationProvider = TestLocationProvider()
+    testLocationProvider.setLocation(37.7749, -122.4194) // Mocked location
+
+    mockkObject(LocationProviderSingleton)
+    every { LocationProviderSingleton.getInstance(any()) } returns testLocationProvider
+
+    // Act: Render the FeedScreen with no posts
+    setFeedScreenContent(emptyList())
+
+    // Wait for the location to emit
+    composeTestRule.waitForIdle()
+
+    // Assert: "No images available" message is displayed
+    composeTestRule.onNodeWithTag("feed_no_images_available").assertExists().assertIsDisplayed()
+  }
+
+  @Test
+  fun testFeedDisplaysLoadingIndicatorWhenLocationIsNull() {
+    // Arrange: Mock location provider and permissions
+    val testLocationProvider = TestLocationProvider()
+    testLocationProvider.setLocation(null, null) // No location emitted
+
+    mockkObject(LocationProviderSingleton)
+    every { LocationProviderSingleton.getInstance(any()) } returns testLocationProvider
+
+    // Act: Render the FeedScreen
+    setFeedScreenContent(emptyList())
+
+    // Wait for the composition to stabilize
+    composeTestRule.waitForIdle()
+
+    // Assert: Loading indicator (CircularProgressIndicator) is displayed
+    composeTestRule.onNodeWithTag("loading_indicator_test_tag").assertExists().assertIsDisplayed()
+  }
+
+  @Test
+  fun testFeedDisplaysNoImagesMessageWithPlaceholderImage() {
+    // Arrange: Mock location provider and permissions
+    val testLocationProvider = TestLocationProvider()
+    testLocationProvider.setLocation(37.7749, -122.4194) // Mocked location
+
+    mockkObject(LocationProviderSingleton)
+    every { LocationProviderSingleton.getInstance(any()) } returns testLocationProvider
+
+    // Act: Render the FeedScreen with no posts
+    setFeedScreenContent(emptyList())
+
+    // Wait for any updates to complete
+    composeTestRule.waitForIdle()
+
+    // Assert: Placeholder image is displayed
+    composeTestRule.onNodeWithTag("no_images_placeholder").assertExists().assertIsDisplayed()
+  }
 }

app/src/main/java/com/github/lookupgroup27/lookup/ui/feed/Feed.kt

@@ -164,17 +164,38 @@ fun FeedScreen(
                     if (nearbyPosts.isEmpty()) {
                       // Loading or empty state
                       Box(
-                          modifier =
-                              Modifier.fillMaxSize()
-                                  .testTag(stringResource(R.string.loading_indicator_test_tag)),
+                          modifier = Modifier.fillMaxSize().testTag("loading_indicator_test_tag"),
                           contentAlignment = Alignment.Center) {
                             if (!locationPermissionGranted) {
                               Text(
                                   text = stringResource(R.string.location_permission_required),
                                   style =
                                       MaterialTheme.typography.bodyLarge.copy(color = Color.White))
+                            } else if (locationProvider.currentLocation.value == null) {
+                              CircularProgressIndicator(
+                                  color = Color.White) // Still fetching location
                             } else {
-                              CircularProgressIndicator(color = Color.White)
+                              Column(
+                                  horizontalAlignment = Alignment.CenterHorizontally,
+                                  verticalArrangement = Arrangement.Center) {
+                                    // Add PNG image above the message
+                                    Image(
+                                        painter = painterResource(R.drawable.no_images_placeholder),
+                                        contentDescription =
+                                            stringResource(R.string.feed_no_images_available),
+                                        modifier =
+                                            Modifier.size(180.dp).testTag("no_images_placeholder"))
+
+                                    Spacer(modifier = Modifier.height(16.dp))
+
+                                    // Display "No images available" message
+                                    Text(
+                                        text = stringResource(R.string.feed_no_images_available),
+                                        modifier = Modifier.testTag("feed_no_images_available"),
+                                        style =
+                                            MaterialTheme.typography.bodyLarge.copy(
+                                                color = Color.White))
+                                  }
                             }
                           }
                     } else {

app/src/main/res/values/strings.xml

@@ -24,4 +24,5 @@
     <string name="map_button_reset_text">Reset</string>
     <string name="map_slider_test_tag">map_slider_tag</string>
     <string name="nearby_posts_title">Nearby Stargazers</string>
+    <string name="feed_no_images_available">No images are available</string>
 </resources>