Add online state test, Update offline state tests

app/src/androidTest/kotlin/com/google/samples/apps/nowinandroid/ui/NiaAppStateTest.kt

@@ -56,7 +56,7 @@ class NiaAppStateTest {
     // Create the test dependencies.
     private val networkMonitor = TestNetworkMonitor()
 
-    private val errorMonitor = TestErrorMonitor()
+    private val errorMonitor = TestErrorMonitor(networkMonitor)
 
     private val timeZoneMonitor = TestTimeZoneMonitor()
 
@@ -122,7 +122,7 @@ class NiaAppStateTest {
             )
         }
 
-        backgroundScope.launch { state.isOffline.collect() }
+        backgroundScope.launch { state.isOfflineState.collect() }
         networkMonitor.setConnected(false)
         assertEquals(
             true,
@@ -130,6 +130,26 @@ class NiaAppStateTest {
         )
     }
 
+    @Test
+    fun niaAppState_whenNetworkMonitorIsOnline_StateIsOnline() = runTest(UnconfinedTestDispatcher()) {
+        composeTestRule.setContent {
+            state = NiaAppState(
+                navController = NavHostController(LocalContext.current),
+                coroutineScope = backgroundScope,
+                errorMonitor = errorMonitor,
+                userNewsResourceRepository = userNewsResourceRepository,
+                timeZoneMonitor = timeZoneMonitor,
+            )
+        }
+
+        backgroundScope.launch { state.isOfflineState.collect() }
+        networkMonitor.setConnected(true)
+        assertEquals(
+            false,
+            state.isOfflineState.value,
+        )
+    }
+
     @Test
     fun niaAppState_differentTZ_withTimeZoneMonitorChange() = runTest(UnconfinedTestDispatcher()) {
         composeTestRule.setContent {

core/testing/src/main/kotlin/com/google/samples/apps/nowinandroid/core/testing/util/TestErrorMonitor.kt

@@ -20,11 +20,11 @@ import com.google.samples.apps.nowinandroid.core.data.util.ErrorMessage
 import com.google.samples.apps.nowinandroid.core.data.util.ErrorMonitor
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.flow.map
 
-class TestErrorMonitor : ErrorMonitor {
+class TestErrorMonitor(networkMonitor: TestNetworkMonitor) : ErrorMonitor {
     override var offlineMessage: String? = "offline"
-    override val isOffline: Flow<Boolean>
+    override val isOffline: Flow<Boolean> = networkMonitor.isOnline.map { !it }
-        get() = flowOf(false)
     override fun addShortErrorMessage(
         error: String,
         label: String?,