如何在 Kotlin 中调用 assertEquals with Double Epsilon/Precision？

Question

我想知道，在 Kotlin 中，是否有可能调用与 java 方法等效的方法：

assertEquals(double expected, double actual, double precision)

因为每次我都得到这个方法

assertEquals(expected: T, actual: T, message: String)

而且我找不到带有精度参数的那个。 我想拨打 Java 也应该没问题。

我对该方法的调用：

assertEquals(5000.00, calculateCouponAmount(basicFaceValue, basicInterestRate, amortizationBullet, couponNumber1), 0.01)

我收到一个错误，因为 0.01 进入“消息”字段

Answer 1

我已经想通了！

这是怎么做的

import org.junit.*
import Kotlin.Test.assertEquals

Assert.assertEquals(expected, actual, precision) // to use the jUnit standard one
assertEquals(expected, actual, message) // to use the Kotlin one

Answer 2

我找不到，所以我创建了自己的一组函数：

import java.math.BigDecimal
import kotlin.math.abs
import kotlin.test.asserter

internal fun assertEquals(expected: Double, actual: Double?, epsilon: Double, message: String? = null) {
    asserter.assertNotNull(null, actual)
    asserter.assertTrue({ messagePrefix(message) + "Expected <$expected>, actual <$actual>, should differ no more than <$epsilon>." },
            abs(expected - actual!!) <= epsilon)
}

internal fun assertEquals(expected: BigDecimal, actual: BigDecimal?, epsilon: Double, message: String? = null) {
    asserter.assertNotNull(null, actual)
    asserter.assertTrue({ messagePrefix(message) + "Expected <$expected>, actual <$actual>, should differ no more than <$epsilon>." },
            (expected - actual!!).abs().toDouble() <= epsilon)
}

internal fun assertEquals(expected: Double, actual: BigDecimal?, epsilon: Double, message: String? = null) {
    asserter.assertNotNull(null, actual)
    asserter.assertTrue({ messagePrefix(message) + "Expected <$expected>, actual <$actual>, should differ no more than <$epsilon>." },
            abs(expected - actual!!.toDouble()) <= epsilon)
}

internal fun messagePrefix(message: String?) = if (message == null) "" else "$message. "

Answer 3

只需检查以确保您正在导入具有所需assertEquals方法的正确类。 除此之外，您可能想要验证calculateCouponAmount()方法是否返回Double 。

Answer 4

它现在包含在官方 API 中，用于 Double 和 Float：

fun assertEquals(
    expected: Double,
    actual: Double,
    absoluteTolerance: Double,
    message: String? = null
): Unit

fun assertEquals(
    expected: Float,
    actual: Float,
    absoluteTolerance: Float,
    message: String? = null
): Unit

参见https://kotlinlang.org/api/latest/kotlin.test/kotlin.test/assert-equals.html