41 lines
1.1 KiB
Kotlin
41 lines
1.1 KiB
Kotlin
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fun main() {
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testMap()
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testFilter()
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testFold()
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shouldHandleNullableTypes()
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}
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fun testMap() {
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assertEquals(Option.just(3).map { it * 2 }.map { "$it" }.getOrNull(), "6")
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assertEquals(Option.just(listOf(1)).map { it.first() }.getOrNull(), 1)
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assertEquals(Option.none<Int>().map { error("Should not be executed") }.getOrNull(), null)
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}
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fun testFilter() {
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assertEquals(Option.just(6).filter { it > 5 }.getOrNull(), 6)
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assertEquals(Option.just(6).filter { it < 5 }.getOrNull(), null)
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}
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fun testFold() {
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assertEquals(Option.just(2).map { it * 2 }.fold({ it / 2 }, { error("Should not be executed") }), 2)
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assertEquals(Option.none<Int>().fold({ error("Should not be executed") }, { 2 }), 2)
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}
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fun shouldHandleNullableTypes() {
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assertEquals(Option.just<Int?>(null).map { it ?: 5 }.getOrNull(), 5)
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assertEquals(
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Option.just<List<String>>(emptyList())
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.map { it.firstOrNull() }
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.fold({ it }, { error("Should not be executed") }),
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null
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)
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}
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private fun <T> assertEquals(x: T, y: T) {
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if (x != y) {
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error("$x was not equal to $y")
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}
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}
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