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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
package org.mozilla.tv.firefox.integration
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.Observer
import org.junit.Assert.assertEquals
import org.junit.Assert.fail
import org.junit.Before
import org.junit.Rule
import org.junit.Test
import org.mozilla.tv.firefox.helpers.MainActivityTestRule
import org.mozilla.tv.firefox.ext.LiveDataCombiners
@Suppress("TestFunctionName")
// Espresso test functions can't have spaces in their names, even between backticks. This prevents
// the linting error for starting a function with an uppercase letter
class LiveDataCombineLatestTest {
@get:Rule val activityTestRule = MainActivityTestRule()
private lateinit var source1: MutableLiveData<Int>
private lateinit var source2: MutableLiveData<String>
private lateinit var result: MutableLiveData<Pair<Int, String>>
@Before
fun setup() {
source1 = MutableLiveData()
source2 = MutableLiveData()
result = LiveDataCombiners.combineLatest(source1, source2) { v1, v2 -> Pair(v1, v2) } as MutableLiveData<Pair<Int, String>>
}
@Test
fun WHEN_the_first_source_never_emits_THEN_the_result_should_never_emit() {
activityTestRule.runOnUiThread {
result.observeForever { fail("Shouldn't emit anything") }
source2.value = "A"
source2.value = "B"
source2.value = "C"
}
}
@Test
fun WHEN_the_second_source_never_emits_THEN_the_result_should_never_emit() {
activityTestRule.runOnUiThread {
result.observeForever { fail("Shouldn't emit anything") }
source1.value = 1
source1.value = 2
source1.value = 3
}
}
@Test
fun WHEN_both_sources_emit_THEN_the_result_should_emit_pairs() {
activityTestRule.runOnUiThread {
var observer = Observer<Pair<Int, String>> { assertEquals(Pair(1, "A"), it) }
result.observeForever(observer)
source1.value = 1
source2.value = "A"
result.removeObserver(observer)
source1.value = 2
source2.value = "B"
observer = Observer { assertEquals(Pair(2, "B"), it) }
result.observeForever(observer)
}
}
@Test
fun GIVEN_a_value_has_already_been_emitted_WHEN_only_one_source_emits_THEN_the_result_should_use_cached_value() {
activityTestRule.runOnUiThread {
source1.value = 1
source2.value = "A"
source1.value = 2
result.observeForever { assertEquals(Pair(2, "A"), it) }
}
}
}