Introduce currentValue(kosmos) for testing StateFlows (893cd1b6) · Commits · e / os / android_frameworks_base

packages/SystemUI/multivalentTests/src/com/android/systemui/kosmos/GeneralKosmosTest.kt

0 → 100644

+74 −0

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		/*
		* Copyright (C) 2024 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 com.android.systemui.kosmos

		import androidx.test.ext.junit.runners.AndroidJUnit4
		import androidx.test.filters.SmallTest
		import com.android.systemui.SysuiTestCase
		import com.google.common.truth.Truth.assertThat
		import kotlinx.coroutines.flow.MutableStateFlow
		import kotlinx.coroutines.flow.SharingStarted
		import kotlinx.coroutines.flow.flow
		import kotlinx.coroutines.flow.map
		import kotlinx.coroutines.flow.stateIn
		import kotlinx.coroutines.test.runTest
		import org.junit.Test
		import org.junit.runner.RunWith

		@SmallTest
		@RunWith(AndroidJUnit4::class)
		class GeneralKosmosTest : SysuiTestCase() {
		@Test
		fun stateCurrentValueMutableStateFlow() = runTest {
		val source = MutableStateFlow(1)
		val mapped =
		source
		.map { it * 2 }
		.stateIn(
		scope = backgroundScope,
		started = SharingStarted.WhileSubscribed(),
		initialValue = source.value * 2,
		)
		assertThat(currentValue(mapped)).isEqualTo(2)

		source.value = 3
		assertThat(currentValue(mapped)).isEqualTo(6)
		}

		@Test
		fun stateCurrentValueOnEmittedFlow() = runTest {
		val source = flow {
		emit(1)
		emit(2)
		}
		val mapped =
		source
		.map { it * 2 }
		.stateIn(
		scope = backgroundScope,
		started = SharingStarted.WhileSubscribed(),
		initialValue = 2,
		)
		assertThat(currentValue(mapped)).isEqualTo(4)
		}

		@Test
		fun currentValueIsNull() = runTest {
		val source = MutableStateFlow<Int?>(null)
		assertThat(currentValue(source)).isEqualTo(null)
		}
		}

packages/SystemUI/multivalentTests/src/com/android/systemui/scene/SceneFrameworkIntegrationTest.kt

+3 −2

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		@@ -47,6 +47,7 @@ import com.android.systemui.keyguard.KeyguardViewMediator
		import com.android.systemui.keyguard.ui.viewmodel.lockscreenUserActionsViewModel
		import com.android.systemui.kosmos.Kosmos
		import com.android.systemui.kosmos.collectLastValue
		import com.android.systemui.kosmos.currentValue
		import com.android.systemui.kosmos.runCurrent
		import com.android.systemui.kosmos.runTest
		import com.android.systemui.kosmos.testScope
		@@ -77,6 +78,7 @@ import kotlinx.coroutines.flow.flowOf
		import kotlinx.coroutines.launch
		import kotlinx.coroutines.test.advanceTimeBy
		import kotlinx.coroutines.test.runCurrent
		import kotlinx.coroutines.test.runTest
		import org.junit.Before
		import org.junit.Test
		import org.junit.runner.RunWith
		@@ -399,9 +401,8 @@ class SceneFrameworkIntegrationTest : SysuiTestCase() {
		* Note that this doesn't assert what the current scene is in the UI.
		*/
		private fun Kosmos.assertCurrentScene(expected: SceneKey) {
		testScope.runCurrent()
		assertWithMessage("Current scene mismatch!")
		.that(sceneContainerViewModel.currentScene.value)
		.that(currentValue(sceneContainerViewModel.currentScene))
		.isEqualTo(expected)
		}

packages/SystemUI/tests/utils/src/com/android/systemui/kosmos/GeneralKosmos.kt

+27 −0

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		@@ -8,7 +8,10 @@ import com.android.systemui.kosmos.Kosmos.Fixture
		import com.android.systemui.settings.brightness.ui.BrightnessWarningToast
		import com.android.systemui.util.mockito.mock
		import kotlin.coroutines.CoroutineContext
		import kotlinx.coroutines.ExperimentalCoroutinesApi
		import kotlinx.coroutines.flow.Flow
		import kotlinx.coroutines.flow.StateFlow
		import kotlinx.coroutines.launch
		import kotlinx.coroutines.test.StandardTestDispatcher
		import kotlinx.coroutines.test.TestScope
		import kotlinx.coroutines.test.UnconfinedTestDispatcher
		@@ -58,3 +61,27 @@ fun Kosmos.runCurrent() = testScope.runCurrent()
		fun <T> Kosmos.collectLastValue(flow: Flow<T>) = testScope.collectLastValue(flow)

		fun <T> Kosmos.collectValues(flow: Flow<T>): FlowValue<List<T>> = testScope.collectValues(flow)

		/**
		* Retrieve the current value of this [StateFlow] safely. Needs a [TestScope] in order to make sure
		* that all pending tasks have run before returning a value. Tests that directly access
		* [StateFlow.value] may be incorrect, since the value returned may be stale if the current test
		* dispatcher is a [StandardTestDispatcher].
		*
		* If you want to assert on a [Flow] that is not a [StateFlow], please use
		* [TestScope.collectLastValue], to make sure that the desired value is captured when emitted.
		*/
		@OptIn(ExperimentalCoroutinesApi::class)
		fun <T> TestScope.currentValue(stateFlow: StateFlow<T>): T {
		val values = mutableListOf<T>()
		val job = backgroundScope.launch { stateFlow.collect(values::add) }
		runCurrent()
		job.cancel()
		// StateFlow should always have at least one value
		return values.last()
		}

		/** Retrieve the current value of this [StateFlow] safely. See `currentValue(TestScope)`. */
		fun <T> Kosmos.currentValue(stateFlow: StateFlow<T>): T {
		return testScope.currentValue(stateFlow)
		}