Question

我正在使用最新的FlatSpec库来测试我的代码。下面是我为了测试代码而编写的函数：

def compareToHello (a:String) = {
 a match {case "Hello" => println ("Hello")
case _ => println("error")}
}

对于测试部分：

import org.scalatest.{ FlatSpec, GivenWhenThen, Matchers } 
class AestA extends FlatSpec with GivenWhenThen with Matchers {
"Implemented function" should "compare input string to hello"in {
val test=compareToHello("Hello)
assert 
}

}

由于我的功能输出显示在控制台中，因此我遇到了关于断言内容的问题。我正在学习scala，这就是我提出这类问题的原因非常感谢

Answer 1

public void fillGaps() { tempGaps = new int[difference]; finalTemps = new int[difference]; for (int i = 0; i < difference; i++) { //navigate through every temperature tempGaps[i] = temp[0] + i; //assign the current temperature Integer frequency = map.get(new Integer(tempGaps[i])); //fetch the frequency finalTemps[i] = frequency == null ? 0 : frequency; //assign 0 if null, otherwise frequency if not null } }是一个副作用：您无法推断println的输出。

提取

compareToHello

你可以做的是通过返回一个字符串来使这个函数变得纯净：

scala> def f: Unit = println("Hello")
f: Unit

scala> f
Hello

scala> f == "Hello"
<console>:9: warning: comparing values of types Unit and String using `==' will always yield false
              f == "Hello"
                ^
Hello
res7: Boolean = false

scala> f == ()
<console>:9: warning: comparing values of types Unit and Unit using `==' will always yield true
              f == ()
                ^
warning: there was one deprecation warning; re-run with -deprecation for details
Hello
res8: Boolean = true

并断言如下：

def compareToHello (a:String) = a match {
  case "Hello" => "Hello"
  case _ => "error"
}

println

1 个答案: