feat(home): 팔로잉 ViewModel을 추가한다

app/src/test/java/kr/co/vividnext/sodalive/v2/main/home/HomeFollowingViewModelTest.kt

@@ -0,0 +1,176 @@
+package kr.co.vividnext.sodalive.v2.main.home
+
+import android.app.Application
+import android.content.Context
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Observer
+import androidx.test.core.app.ApplicationProvider
+import io.reactivex.rxjava3.android.plugins.RxAndroidPlugins
+import io.reactivex.rxjava3.core.Scheduler
+import io.reactivex.rxjava3.core.Single
+import io.reactivex.rxjava3.plugins.RxJavaPlugins
+import io.reactivex.rxjava3.schedulers.Schedulers
+import kr.co.vividnext.sodalive.R
+import kr.co.vividnext.sodalive.common.ApiResponse
+import kr.co.vividnext.sodalive.common.SharedPreferenceManager
+import kr.co.vividnext.sodalive.common.UtcRelativeTimeTextFormatter
+import kr.co.vividnext.sodalive.v2.main.home.data.FollowingCreatorResponse
+import kr.co.vividnext.sodalive.v2.main.home.data.HomeFollowingApi
+import kr.co.vividnext.sodalive.v2.main.home.data.HomeFollowingRepository
+import kr.co.vividnext.sodalive.v2.main.home.data.HomeFollowingTabResponse
+import kr.co.vividnext.sodalive.v2.main.home.model.HomeFollowingUiState
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+
+@RunWith(RobolectricTestRunner::class)
+@Config(sdk = [28], application = Application::class)
+class HomeFollowingViewModelTest {
+
+    private val context: Context = ApplicationProvider.getApplicationContext()
+    private val formatter = UtcRelativeTimeTextFormatter { "relative:$it" }
+    private lateinit var api: FakeHomeFollowingApi
+    private lateinit var viewModel: HomeFollowingViewModel
+
+    @Before
+    fun setUp() {
+        setImmediateRxSchedulers()
+        SharedPreferenceManager.resetForTest()
+        SharedPreferenceManager.init(context)
+        SharedPreferenceManager.token = "test-token"
+        api = FakeHomeFollowingApi()
+        viewModel = HomeFollowingViewModel(
+            repository = HomeFollowingRepository(api),
+            relativeTimeTextFormatter = formatter
+        )
+    }
+
+    @After
+    fun tearDown() {
+        RxJavaPlugins.reset()
+        RxAndroidPlugins.reset()
+        SharedPreferenceManager.resetForTest()
+    }
+
+    @Test
+    fun `loadFollowing은 loading 후 content 상태를 발행한다`() {
+        api.enqueueSuccess(response(followingCreators = listOf(creator())))
+
+        viewModel.loadFollowing()
+
+        val state = viewModel.followingStateLiveData.requireValue() as HomeFollowingUiState.Content
+        assertEquals(1L, state.followingCreators.items.single().creatorId)
+        assertFalse(viewModel.isLoading.requireValue() ?: true)
+    }
+
+    @Test
+    fun `blank token이면 repository에 null auth header를 전달한다`() {
+        SharedPreferenceManager.token = "   "
+        api.enqueueSuccess(response(followingCreators = listOf(creator())))
+
+        viewModel.loadFollowing()
+
+        assertEquals(listOf(null), api.calls)
+    }
+
+    @Test
+    fun `token이 있으면 repository에 Bearer auth header를 전달한다`() {
+        SharedPreferenceManager.token = "test-token"
+        api.enqueueSuccess(response(followingCreators = listOf(creator())))
+
+        viewModel.loadFollowing()
+
+        assertEquals(listOf("Bearer test-token"), api.calls)
+    }
+
+    @Test
+    fun `isLoginRequired true 응답은 login required 상태를 발행한다`() {
+        api.enqueueSuccess(response(isLoginRequired = true, followingCreators = listOf(creator())))
+
+        viewModel.loadFollowing()
+
+        assertTrue(viewModel.followingStateLiveData.requireValue() is HomeFollowingUiState.LoginRequired)
+    }
+
+    @Test
+    fun `API success이지만 data가 null이면 error 상태와 toast를 발행한다`() {
+        api.enqueueSuccess(ApiResponse(true, null, null))
+
+        viewModel.loadFollowing()
+
+        assertTrue(viewModel.followingStateLiveData.requireValue() is HomeFollowingUiState.Error)
+        assertEquals(R.string.common_error_unknown, viewModel.toastLiveData.requireValue()?.resId)
+    }
+
+    @Test
+    fun `API failure throwable이면 error 상태와 toast를 발행한다`() {
+        api.enqueue(Single.error(IllegalStateException("network")))
+
+        viewModel.loadFollowing()
+        val state = viewModel.followingStateLiveData.requireValue() as HomeFollowingUiState.Error
+
+        assertEquals("network", state.message)
+        assertEquals(R.string.common_error_unknown, viewModel.toastLiveData.requireValue()?.resId)
+    }
+
+    private fun setImmediateRxSchedulers() {
+        val trampoline = { _: Scheduler -> Schedulers.trampoline() }
+        RxJavaPlugins.setIoSchedulerHandler(trampoline)
+        RxAndroidPlugins.setInitMainThreadSchedulerHandler { Schedulers.trampoline() }
+        RxAndroidPlugins.setMainThreadSchedulerHandler { Schedulers.trampoline() }
+    }
+
+    private fun response(
+        isLoginRequired: Boolean = false,
+        followingCreators: List<FollowingCreatorResponse> = emptyList()
+    ) = HomeFollowingTabResponse(
+        isLoginRequired = isLoginRequired,
+        followingCreators = followingCreators,
+        onAirLives = emptyList(),
+        recentChats = emptyList(),
+        monthlySchedules = emptyList(),
+        recentNews = emptyList()
+    )
+
+    private fun creator() = FollowingCreatorResponse(
+        creatorId = 1L,
+        creatorNickname = "creator",
+        creatorProfileImageUrl = "https://example.com/creator.png"
+    )
+
+    private fun <T> LiveData<T>.requireValue(): T? {
+        var value: T? = null
+        val observer = Observer<T> { value = it }
+        observeForever(observer)
+        removeObserver(observer)
+        return value
+    }
+
+    private class FakeHomeFollowingApi : HomeFollowingApi {
+        val calls = mutableListOf<String?>()
+        private val responses = ArrayDeque<Single<ApiResponse<HomeFollowingTabResponse>>>()
+
+        fun enqueueSuccess(response: HomeFollowingTabResponse) {
+            enqueueSuccess(ApiResponse(true, response, null))
+        }
+
+        fun enqueueSuccess(response: ApiResponse<HomeFollowingTabResponse>) {
+            enqueue(Single.just(response))
+        }
+
+        fun enqueue(response: Single<ApiResponse<HomeFollowingTabResponse>>) {
+            responses.addLast(response)
+        }
+
+        override fun getFollowing(authHeader: String?): Single<ApiResponse<HomeFollowingTabResponse>> {
+            calls.add(authHeader)
+            return responses.removeFirst()
+        }
+    }
+}