activity/activity-ktx/src/androidTest/java/androidx/activity/contextaware/ContextAwareTest.kt

/*
 * Copyright 2020 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.activity.contextaware

import androidx.test.core.app.ApplicationProvider
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.filters.SmallTest
import com.google.common.truth.Truth.assertThat
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import org.junit.Test
import org.junit.runner.RunWith

@SmallTest
@RunWith(AndroidJUnit4::class)
class ContextAwareTest {

    @Test
    fun alreadyAvailable() = runBlocking(Dispatchers.Main) {
        val contextAware = TestContextAware()
        contextAware.dispatchOnContextAvailable()
        var result = "initial"
        val receivedResult = contextAware.withContextAvailable {
            result
        }
        result = "after"
        assertThat(receivedResult).isEqualTo("initial")
    }

    @Test
    fun suspending() = runBlocking(Dispatchers.Main) {
        val contextAware = TestContextAware()
        var result = "initial"
        launch {
            contextAware.dispatchOnContextAvailable()
            result = "post dispatch"
        }
        val receivedResult = contextAware.withContextAvailable {
            result
        }
        contextAware.addOnContextAvailableListener {
            result = "after"
        }
        assertThat(receivedResult).isEqualTo("initial")
    }
}

private class TestContextAware : ContextAware {
    private val contextAwareHelper = ContextAwareHelper()

    override fun peekAvailableContext() = contextAwareHelper.peekAvailableContext()

    override fun addOnContextAvailableListener(listener: OnContextAvailableListener) {
        contextAwareHelper.addOnContextAvailableListener(listener)
    }

    override fun removeOnContextAvailableListener(listener: OnContextAvailableListener) {
        contextAwareHelper.removeOnContextAvailableListener(listener)
    }

    fun dispatchOnContextAvailable() {
        contextAwareHelper.dispatchOnContextAvailable(
            ApplicationProvider.getApplicationContext()
        )
    }
}