kotlin + LiveData 测试

viewModel测试：https://developer.android.com/codelabs/basic-android-kotlin-compose-test-viewmodel#3

  androidTestImplementation "org.jetbrains.kotlin:kotlin-test:1.9.0"androidTestImplementation 'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.7.3'

import androidx.lifecycle.MutableLiveData
import androidx.test.espresso.action.ViewActions.*
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.filters.LargeTest
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.Dispatchers.Main
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import kotlinx.coroutines.test.runTest
import org.junit.Assert.assertEquals
import org.junit.Test
import org.junit.runner.RunWith@RunWith(AndroidJUnit4::class)
@LargeTest
class  LiveDataTest{@Testfun testLiveDataValueChange() = runTest {val liveData = MutableLiveData("1");var observedValue: String? = nulllaunch(Main){liveData.observeForever { value ->observedValue  = value}}// 在协程中进行异步操作val job  =   launch(Dispatchers.Default) {delay(1000)// 更改 LiveData 的值liveData.postValue("2")}job.join()assertEquals(observedValue, "2")assertEquals(liveData.value, "2")}}