| /* |
| * Copyright 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.paging |
| |
| import androidx.arch.core.executor.ArchTaskExecutor |
| import androidx.arch.core.executor.TaskExecutor |
| import androidx.lifecycle.Lifecycle |
| import androidx.lifecycle.LifecycleOwner |
| import androidx.lifecycle.LifecycleRegistry |
| import androidx.lifecycle.Observer |
| import androidx.paging.PagedList.LoadState.IDLE |
| import androidx.paging.PagedList.LoadState.LOADING |
| import androidx.paging.PagedList.LoadState.RETRYABLE_ERROR |
| import androidx.paging.PagedList.LoadType.REFRESH |
| import androidx.test.filters.SmallTest |
| import androidx.testutils.TestDispatcher |
| import androidx.testutils.TestExecutor |
| import kotlinx.coroutines.Dispatchers |
| import kotlinx.coroutines.ExperimentalCoroutinesApi |
| import kotlinx.coroutines.Runnable |
| import kotlinx.coroutines.test.resetMain |
| import kotlinx.coroutines.test.setMain |
| import org.junit.After |
| import org.junit.Assert.assertEquals |
| import org.junit.Assert.assertNotNull |
| import org.junit.Assert.assertNotSame |
| import org.junit.Assert.assertSame |
| import org.junit.Assert.assertTrue |
| import org.junit.Assert.fail |
| import org.junit.Before |
| import org.junit.Test |
| import org.junit.runner.RunWith |
| import org.junit.runners.JUnit4 |
| |
| @SmallTest |
| @RunWith(JUnit4::class) |
| class LivePagedListBuilderTest { |
| private val mainDispatcher = TestDispatcher() |
| private val backgroundExecutor = TestExecutor() |
| private val lifecycleOwner = object : LifecycleOwner { |
| private val lifecycle = LifecycleRegistry(this) |
| |
| override fun getLifecycle(): Lifecycle { |
| return lifecycle |
| } |
| |
| fun handleEvent(event: Lifecycle.Event) { |
| lifecycle.handleLifecycleEvent(event) |
| } |
| } |
| |
| @ExperimentalCoroutinesApi |
| @Before |
| fun setup() { |
| Dispatchers.setMain(mainDispatcher) |
| ArchTaskExecutor.getInstance().setDelegate(object : TaskExecutor() { |
| override fun executeOnDiskIO(runnable: Runnable) { |
| fail("IO executor should be overwritten") |
| } |
| |
| override fun postToMainThread(runnable: Runnable) { |
| runnable.run() |
| } |
| |
| override fun isMainThread(): Boolean { |
| return true |
| } |
| }) |
| lifecycleOwner.handleEvent(Lifecycle.Event.ON_START) |
| } |
| |
| @ExperimentalCoroutinesApi |
| @After |
| fun teardown() { |
| lifecycleOwner.handleEvent(Lifecycle.Event.ON_STOP) |
| ArchTaskExecutor.getInstance().setDelegate(null) |
| Dispatchers.resetMain() |
| } |
| |
| class MockDataSourceFactory { |
| fun create(): PagedSource<Int, String> { |
| return MockPagedSource() |
| } |
| |
| var throwable: Throwable? = null |
| |
| fun enqueueRetryableError() { |
| throwable = RETRYABLE_EXCEPTION |
| } |
| |
| private inner class MockPagedSource : PagedSource<Int, String>() { |
| override val keyProvider = KeyProvider.Positional<String>() |
| |
| override suspend fun load(params: LoadParams<Int>) = when (params.loadType) { |
| LoadType.INITIAL -> loadInitial(params) |
| else -> loadRange() |
| } |
| |
| override fun isRetryableError(error: Throwable) = error === RETRYABLE_EXCEPTION |
| |
| private fun loadInitial(params: LoadParams<Int>): LoadResult<Int, String> { |
| assertEquals(2, params.pageSize) |
| |
| throwable?.let { error -> |
| throwable = null |
| throw error |
| } |
| |
| val data = listOf("a", "b") |
| return LoadResult( |
| data = data, |
| offset = 0, |
| itemsBefore = 0, |
| itemsAfter = 4 - data.size |
| ) |
| } |
| |
| private fun loadRange(): LoadResult<Int, String> { |
| return LoadResult(data = listOf("c", "d"), offset = 0) |
| } |
| } |
| } |
| |
| @Test |
| fun executorBehavior() { |
| // specify a background dispatcher via builder, and verify it gets used for all loads, |
| // overriding default IO dispatcher |
| val livePagedList = LivePagedListBuilder(MockDataSourceFactory()::create, 2) |
| .setFetchExecutor(backgroundExecutor) |
| .build() |
| |
| val pagedListHolder: Array<PagedList<String>?> = arrayOfNulls(1) |
| |
| livePagedList.observe(lifecycleOwner, Observer<PagedList<String>> { newList -> |
| pagedListHolder[0] = newList |
| }) |
| |
| // initially, immediately get passed empty initial list |
| assertNotNull(pagedListHolder[0]) |
| assertTrue(pagedListHolder[0] is InitialPagedList<*, *>) |
| |
| // flush loadInitial, done with passed executor |
| drain() |
| |
| val pagedList = pagedListHolder[0] |
| assertNotNull(pagedList) |
| assertEquals(listOf("a", "b", null, null), pagedList) |
| |
| // flush loadRange |
| pagedList!!.loadAround(2) |
| drain() |
| |
| assertEquals(listOf("a", "b", "c", "d"), pagedList) |
| } |
| |
| data class LoadState( |
| val type: PagedList.LoadType, |
| val state: PagedList.LoadState, |
| val error: Throwable? |
| ) |
| |
| @Test |
| fun failedLoad() { |
| val factory = MockDataSourceFactory() |
| factory.enqueueRetryableError() |
| |
| val livePagedList = LivePagedListBuilder(factory::create, 2) |
| .setFetchExecutor(backgroundExecutor) |
| .build() |
| |
| val pagedListHolder: Array<PagedList<String>?> = arrayOfNulls(1) |
| |
| livePagedList.observe(lifecycleOwner, Observer<PagedList<String>> { newList -> |
| pagedListHolder[0] = newList |
| }) |
| |
| val loadStates = mutableListOf<LoadState>() |
| |
| // initially, immediately get passed empty initial list |
| val initPagedList = pagedListHolder[0] |
| assertNotNull(initPagedList!!) |
| assertTrue(initPagedList is InitialPagedList<*, *>) |
| |
| val loadStateChangedCallback: LoadStateListener = { type, state, error -> |
| if (type == REFRESH) { |
| loadStates.add(LoadState(type, state, error)) |
| } |
| } |
| initPagedList.addWeakLoadStateListener(loadStateChangedCallback) |
| |
| // flush loadInitial, done with passed dispatcher |
| drain() |
| |
| assertSame(initPagedList, pagedListHolder[0]) |
| // TODO: Investigate removing initial IDLE state from callback updates. |
| assertEquals( |
| listOf( |
| LoadState(REFRESH, IDLE, null), |
| LoadState(REFRESH, LOADING, null), |
| LoadState(REFRESH, RETRYABLE_ERROR, RETRYABLE_EXCEPTION) |
| ), loadStates |
| ) |
| |
| initPagedList.retry() |
| assertSame(initPagedList, pagedListHolder[0]) |
| |
| // flush loadInitial, should succeed now |
| drain() |
| |
| assertNotSame(initPagedList, pagedListHolder[0]) |
| assertEquals(listOf("a", "b", null, null), pagedListHolder[0]) |
| |
| assertEquals( |
| listOf( |
| LoadState(REFRESH, IDLE, null), |
| LoadState(REFRESH, LOADING, null), |
| LoadState(REFRESH, RETRYABLE_ERROR, RETRYABLE_EXCEPTION), |
| LoadState(REFRESH, LOADING, null) |
| ), loadStates |
| ) |
| |
| // the IDLE result shows up on the next PagedList |
| initPagedList.removeWeakLoadStateListener(loadStateChangedCallback) |
| pagedListHolder[0]!!.addWeakLoadStateListener(loadStateChangedCallback) |
| assertEquals( |
| listOf( |
| LoadState(REFRESH, IDLE, null), |
| LoadState(REFRESH, LOADING, null), |
| LoadState(REFRESH, RETRYABLE_ERROR, RETRYABLE_EXCEPTION), |
| LoadState(REFRESH, LOADING, null), |
| LoadState(REFRESH, IDLE, null) |
| ), loadStates |
| ) |
| } |
| |
| private fun drain() { |
| var executed: Boolean |
| do { |
| executed = backgroundExecutor.executeAll() |
| mainDispatcher.executeAll() |
| } while (executed || mainDispatcher.queue.isNotEmpty()) |
| } |
| |
| companion object { |
| val RETRYABLE_EXCEPTION = Exception("retryable") |
| } |
| } |
