ScalaTest:引用NoArgTest

Question

我正在玩弄sharing fixtures，尤其是withFixture(NoArgTest)。但是，如果引用NoArgTest，我的代码将无法编译。

我唯一的依赖：

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

我的代码尝试将NoArgTest引用为一个类型：

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

您可以编写TestSuite#NoArgTest (这是独立于套件的所有NoArgTest的通用类型)，如果您已经有一个实例suite: TestSuite，则可以编写suite.NoArgTest。请注意，如果suite是成员参数，则它们需要在单独的参数列表中：

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

有关更多详细信息，请参阅What are the differences between Scala’s inner classes and Java’s Inner/nested classes?的答案。