问题描述
我刚刚开始使用 ScalaTest,我正在使用以下内容来比较我的规范中的两个双打,如下所示:
I have just started using ScalaTest and I am using the following to compare two Doubles in my spec as follows:
it should "calculate the price" in {
val x = new X(10,10,12,1000)
assert(x.price() === 185.92)
}
即使我输入了错误的 185.92 值来与价格函数返回的值进行比较(对于上述情况,实际上返回 10.23),规范仍在通过.我有其他规范,我只是比较 Ints
并且它们按预期工作.但是涉及 Double
的那些都通过了.除了 assert
我还应该使用其他函数来比较 Double
吗?
The spec is passing even though I have put in a wrong value of 185.92 to compare against what the price function is returning (that actually returns 10.23 for the case above). I have other specs where I just compare Ints
and they work as expected. But the ones involving Doubles
are passing regardless. Is there another functions besides assert
I should be using to compare Doubles
?
def price () : Double
推荐答案
在我看来,你在 行的范围内有一个
,其文档为 这里.Equality[Double]
的隐式实例org.scalactic.TolerantNumerics
It looks to me like you've got an implicit instance of Equality[Double]
in scope along the lines of org.scalactic.TolerantNumerics
, for which the documentation is here.
文档中的示例是:
implicit val doubleEquality = TolerantNumerics.tolerantDoubleEquality(0.01)
但在您的情况下,似乎有人使用非常大的容差值对其进行了实例化.
But it looks like somebody has instantiated it with a really big tolerance value in your case.
您也可以考虑使用 +-
尝试显式容忍:
You may also consider trying explicit tolerance by using +-
:
assert(x.price() === 185.92 +- 0.01)
这篇关于在 ScalaTest 中处理双打的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!