ScalaTest:引用 NoArgTest

ScalaTest: referencing NoArgTest

我正在玩 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>

我的代码试图将 NoArgTest 引用为类型:

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?

你可以写TestSuite#NoArgTest(这是所有独立于套件的NoArgTest的通用类型),或者suite.NoArgTest如果你已经有一个实例suite: TestSuite .请注意,如果 suite 是成员参数,则它们需要位于单独的参数列表中:

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

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