Question

我想知道，在Kotlin中，是否有可能调用相当于java方法：

assertEquals(double expected, double actual, double precision)

因为我每次都会使用此方法

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

我无法找到具有精度参数的那个。我猜这个调用Java也应该没问题。

我对方法的调用：

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

我收到错误，因为0.01收到＆＃34;消息＆＃34;字段

Answer 1

我已经弄清楚了！

这就是它的完成方式

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

我找不到一个，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

只需检查以确保您导入了具有所需assertEquals方法的正确类。除此之外，您可能需要验证calculateCouponAmount()方法是否返回Double。

如何在Kotlin中使用Double Epsilon / Precision调用assertEquals？

3 个答案: