否定在specs2自定义匹配

Question

我在specs2写了一个自定义的匹配如下：

object MyMatchers { 
    def haveHttpStatus(expected:Int) = new StatusMatcher(expected) 
} 

class StatusMatcher(expected:Int) extends Matcher[Option[Future[Result]]] { 

    def apply[R <: Option[Future[Result]]](r: Expectable[R]) = { 
    val v = r.value 
    v match { 
     case None => failure(s"${r.description} was None", r) 
     case Some(fr:Future[Result]) => 
     import play.api.test.Helpers._ 
     val actual:Int = status(fr) 
     result(actual == expected, 
      s"${r.description} has status $actual as expected", 
      s"${r.description} expected status $expected but found $actual", 
      r) 
     case _ => 
     failure(s"${r.description} has unexpected type $v", r) 
    } 
    } 
} 

当我测试了肯定的情况下，它按预期工作：

"return OK" in new WithApplication { 
     val response = route(FakeRequest(HttpVerbs.GET, "/test")) 
     import tools.MyMatchers._ 
     response must haveHttpStatus(OK) 
    } 

但是，当我尝试测试否定的情况下，我得到一个编译错误，“值haveHttpStatus不是org.specs2.matcher.MatchResult [选项[scala.concurrent.Future [play.api.mvc.Result]]]的成员”“

"return OK" in new WithApplication { 
     val response = route(FakeRequest(HttpVerbs.GET, "/test")) 
     import tools.MyMatchers._ 
     response must not haveHttpStatus(OK) 
    } 

我在一个例子中看到（https://gist.github.com/seratch/1414177）自定义匹配器被括在圆括号中。这工作。把'不'结束也工作。

"return OK" in new WithApplication { 
     val response = route(FakeRequest(HttpVerbs.GET, "/test")) 
     import tools.MyMatchers._ 
     response must not (haveHttpStatus(OK)) 
    } 

    "also return OK" in new WithApplication { 
     val response = route(FakeRequest(HttpVerbs.GET, "/test")) 
     import tools.MyMatchers._ 
     response must haveHttpStatus(OK) not 
    } 

但我并不十分清楚为什么这两种方法有效，但最初的否定的尝试不是。如果有人能够阐明这一点，我真的很想了解每种方法的差异。这是在Play Framework 2.4.6项目中，其中specs2为specs2 % Test。

看类型回来，我发现：

"return OK" in new WithApplication { 
    val response = route(FakeRequest(HttpVerbs.GET, "/test")) 
    import tools.MyMatchers._ 
    val matcher1 = haveHttpStatus(OK)  // <-- is type StatusMatcher 
    val matcher2 = (haveHttpStatus(OK))  // <-- is type StatusMatcher 
    val matcher3 = not (haveHttpStatus(OK)) // <-- is type AnyRef with Matcher[Option[Future[Result]]] 
    val matcher4 = not haveHttpStatus(OK) // <-- doesn't compile - gives the error "value haveHttpStatus is not a member of org.specs2.matcher.NotMatcher[Any]" 

    response must haveHttpStatus(OK) 
} 

翻翻AnyBeHaveMatchers，它看起来像我需要haveHttpStatus返回一个MatchResult的，而不是一个StatusMatcher，但我有一个困难时期从这里到那里。

更新：

我通过SizedCheckedMatcher，然后在TraversableBaseMatchers特质作为

def haveSize[T : Sized](check: ValueCheck[Int]) = new SizedCheckedMatcher[T](check, "size") 

然后在TraversableBeHaveMatchers钻，有类HasSize，它返回一个MatchResult的，当你调用

def size(n: Int) : MatchResult[T] = s(outer.haveSize[T](n)) 

这几乎与https://github.com/etorreborre/specs2/blob/master/tests/src/test/scala/org/specs2/matcher/LogicalMatcherSpec.scala中的CustomMatcher示例相同。

问题我打试图复制要么是调用S（）或结果（）的时候，我得到的编译错误

方法MatchResult的特质申请不能在org.specs2访问。 matcher.MatchResult [选项[scala.concurrent.Future [play.api.mvc.Result]]]

Answer 1

如果你想使用的语法与a must not beOk[A]其中beOk是一个定制的匹配器，你需要提供的隐式转换（示例here）：

implicit class NotStatusMatcherMatcher(result: NotMatcher[Option[Future[Result]]]) { 
    def haveHttpStatus(expected:Int) = 
    result.applyMatcher(MyMatchers.haveHttpStatus(expected)) 
} 

并通过一个简单的方法来创建自定义的匹配的方法是使用隐式转换：

import org.specs2.matcher.MatcherImplicits._ 

type Res = Option[Future[Result]] 

def haveHttpStatus(expectedStatus: Int): Matcher[Res] = { actual: Res => 
    actual match { 
    case None => 
     (false, s"the result was None") 

    case Some(fr:Future[Result]) => 
     import play.api.test.Helpers._ 
     val actualStatus = status(fr) 
     (actualStatus == expectedStatus, 
     s"expected status $expectedStatus but found $actualStatus") 

    case v => 
     (false, s"unexpected type ${v.getClass}") 
    } 
}