ScalaTest：引用NoArgTest

Question

我在玩sharing fixtures，特别是与Ftureture（NoArgTest）玩。但是，如果引用NoArgTest，我的代码不会编译。

我唯一的依赖：

<dependency> 
     <groupId>org.scalatest</groupId> 
     <artifactId>scalatest_2.11</artifactId> 
     <version>3.0.0</version> 
    </dependency> 

我的代码试图引用NoArgTest作为类型：

1 class Example { 
2  def foo(test: org.scalatest.TestSuite) = "foo" 
3  def bar(test: org.scalatest.TestSuite.NoArgTest) = "bar" 
4 } 

MVN编译：

[WARNING] Expected all dependencies to require Scala version: 2.11.8 
[WARNING] org.scalatest:scalatest_2.11:3.0.0 requires scala version: 2.11.8 
[WARNING] org.scalactic:scalactic_2.11:3.0.0 requires scala version: 2.11.8 
[WARNING] org.scala-lang:scala-reflect:2.11.8 requires scala version: 2.11.8 
[WARNING] org.scala-lang.modules:scala-xml_2.11:1.0.5 requires scala version: 2.11.7 
[WARNING] Multiple versions of scala libraries detected! 

...

[ERROR] Example.scala:4: error: object TestSuite is not a member of package org.scalatest 
[ERROR] Note: trait TestSuite exists, but it has no companion object. 
[ERROR] def bar(test: org.scalatest.TestSuite.NoArgTest) = "bar" 

为什么？

Answer 1

如果您已经有一个实例suite: TestSuite，您可以编写TestSuite#NoArgTest（这是所有NoArgTest的常见类型，独立于套件）或suite.NoArgTest。请注意，如果suite是一个成员的参数，他们需要的是在不同的参数列表：

def bar(suite: TestSuite)(test: suite.NoArgTest) = ... 

查看答案What are the differences between Scala’s inner classes and Java’s Inner/nested classes?了解更多详情。