chore: test for scrolling

Author: kikoso

maps-app/src/androidTest/java/com/google/maps/android/compose/MapsInLazyColumnTest.kt

@@ -1,6 +1,14 @@
 package com.google.maps.android.compose
 
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.test.assertIsDisplayed
 import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onNodeWithTag
 import androidx.compose.ui.test.onRoot
 import androidx.compose.ui.test.performTouchInput
 import androidx.compose.ui.test.swipeUp
@@ -18,23 +26,53 @@ class MapsInLazyColumnTests {
     val composeTestRule = createComposeRule()
 
     private val mapItems = listOf(
-        MapListItem(id = "1", location = LatLng(1.23, 4.56), zoom = 10f, title = "A"),
-        MapListItem(id = "2", location = LatLng(7.89, 0.12), zoom = 12f, title = "B"),
+        MapListItem(id = "1", location = LatLng(1.23, 4.56), zoom = 10f, title = "Item 1"),
+        MapListItem(id = "2", location = LatLng(7.89, 0.12), zoom = 12f, title = "Item 2"),
+        MapListItem(id = "3", location = LatLng(3.45, 6.78), zoom = 11f, title = "Item 3"),
+        MapListItem(id = "4", location = LatLng(9.01, 2.34), zoom = 13f, title = "Item 4"),
+        MapListItem(id = "5", location = LatLng(5.67, 8.90), zoom = 9f, title = "Item 5"),
+        MapListItem(id = "6", location = LatLng(4.32, 7.65), zoom = 14f, title = "Item 6"),
+        MapListItem(id = "7", location = LatLng(8.76, 1.23), zoom = 10f, title = "Item 7"),
+        MapListItem(id = "8", location = LatLng(2.98, 6.54), zoom = 12f, title = "Item 8"),
+        MapListItem(id = "9", location = LatLng(7.65, 3.21), zoom = 11f, title = "Item 9"),
+        MapListItem(id = "10", location = LatLng(0.12, 9.87), zoom = 13f, title = "Item 10"),
     )
 
+
     private lateinit var cameraPositionStates: Map<MapItemId, CameraPositionState>
 
     private fun initMaps() {
         check(hasValidApiKey) { "Maps API key not specified" }
-        val countDownLatch = CountDownLatch(mapItems.size)
+
         composeTestRule.setContent {
-            MapsInLazyColumn(mapItems, onMapLoaded = {
-                countDownLatch.countDown()
-            })
-        }
+            val lazyListState = rememberLazyListState()
+            val visibleMapCount = remember { mutableStateOf(0) }
+
+            val visibleItems by remember {
+                derivedStateOf {
+                    lazyListState.layoutInfo.visibleItemsInfo.size
+                }
+            }
+
+            LaunchedEffect(visibleItems) {
+                visibleMapCount.value = visibleItems
+            }
+
+            val countDownLatch = CountDownLatch(visibleMapCount.value)
+
+            MapsInLazyColumn(
+                mapItems,
+                lazyListState = lazyListState,
+                onMapLoaded = {
+                    countDownLatch.countDown()
+                }
+            )
 
-        val mapsLoaded = countDownLatch.await(30, TimeUnit.SECONDS)
-        assertTrue("Maps loaded", mapsLoaded)
+            LaunchedEffect(Unit) {
+                val mapsLoaded = countDownLatch.await(30, TimeUnit.SECONDS)
+                assertTrue("Visible maps loaded", mapsLoaded)
+            }
+        }
     }
 
     @Before
@@ -64,4 +102,12 @@ class MapsInLazyColumnTests {
             item.location.assertEquals(cameraPositionStates[item.id]?.position?.target!!)
         }
     }
+
+    @Test
+    fun testScrollToBottom() {
+        initMaps()
+        composeTestRule.onRoot().performTouchInput { swipeUp(durationMillis = 1000) }
+        composeTestRule.waitForIdle()
+        composeTestRule.onNodeWithTag("Item 5").assertIsDisplayed()
+    }
 }

maps-app/src/main/java/com/google/maps/android/compose/MapsInLazyColumnActivity.kt

@@ -20,6 +20,7 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.systemBarsPadding
 import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.foundation.rememberScrollState
@@ -41,7 +42,6 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.testTag
-import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
@@ -142,12 +142,13 @@ class MapsInLazyColumnActivity : ComponentActivity() {
 @Composable
 fun MapsInLazyColumn(
     mapItems: List<MapListItem>,
+    lazyListState: LazyListState = rememberLazyListState(),
     onMapLoaded: () -> Unit
 ) {
 
     var isMapLoaded by remember { mutableStateOf(false) }
 
-    val lazyListState = rememberLazyListState()
+    val lazyListState = lazyListState
 
     val cameraPositionStates = mapItems.associate { item ->
         item.id to rememberCameraPositionState(
@@ -266,7 +267,7 @@ private fun MapCard(
             @Composable
             fun TextWithBackground(text: String, fontWeight: FontWeight = FontWeight.Medium) {
                 Text(
-                    modifier = Modifier.background(Color.White.copy(0.7f)),
+                    modifier = Modifier.background(Color.White.copy(0.7f)).testTag(text),
                     text = text,
                     fontWeight = fontWeight,
                     fontSize = 10.sp