在 Scala 中调用静态模拟时出现 NotAMockException

Question

我正在尝试在 Scala 中使用 PowerMockito 来绕过对 scala.io.Source.fromURL 的调用，这是 Source 类中的静态方法。我已经非常接近让它工作了，但我不断收到NotAMockException。

import com.sun.xml.internal.messaging.saaj.util.ByteInputStream
import org.junit.Test
import org.junit.runner.RunWith
import org.mockito.Mockito
import org.powermock.api.mockito.PowerMockito
import org.powermock.core.classloader.annotations.PrepareForTest
import org.powermock.modules.junit4.PowerMockRunner
import scala.io.BufferedSource
import scala.io.Source

@RunWith(classOf[PowerMockRunner])
@PrepareForTest(Array(classOf[Source]))
class UtilsTest {
  @Test def someTest() {
    PowerMockito.mockStatic(classOf[Source])
    val a = "hello"
    Mockito.doReturn(
      new BufferedSource(
        new ByteInputStream(a.getBytes, 6), 6))
      .when(Source).fromURL(anyString)
  }
}

我在when 行收到以下错误：

org.mockito.exceptions.misusing.NotAMockException: 
Argument passed to when() is not a mock!
Example of correct stubbing:
    doThrow(new RuntimeException()).when(mock).someMethod();

知道我做错了什么吗？我正确地模拟了班级，不是吗？

[编辑]

我的 build.sbt（显然是瘦身）：

import _root_.sbtassembly.AssemblyPlugin.autoImport._

name := "yahoo-cml"

organization := "com.yahoo"

version := "0.1.0"

scalaVersion := "2.11.8"

lazy val yahooNexusRepo = "Nexus" at "http://pp-nexus.office.yahoo.com/content/groups/public"
lazy val cpArchiva = "cpArchiva" at "http://cp-archiva.office.yahoo.com"
lazy val yahooRepo = "NexusXP" at
  "http://pp-nexus.office.yahoo.com/content/repositories/yahoo-releases"

fullResolvers ++= Seq(
  yahooNexusRepo,
  cpArchiva,
  yahooRepo
)

libraryDependencies ++= Seq(
  // scalatest is exlcuded due to conflict with testing libraries.
  "org.apache.spark" %% "spark-core" % "2.1.0" % "provided"
    exclude("org.scalatest", "scalatest_2.11"),
  "org.apache.spark" %% "spark-sql" % "2.1.0" % "provided",
  "org.apache.spark" % "spark-hive_2.11" % "2.1.0" % "provided",
  "org.apache.spark" % "spark-mllib_2.11" % "2.1.0" % "provided",
  // Command line parser
  "com.frugalmechanic" %% "scala-optparse" % "1.1.1",
  //  SBT Junit is supported through junit-interface
  "com.novocode" % "junit-interface" % "0.11" % "test",
  // scalacheck added explicitely to avoid below error due to higher version of scalacheck.
  // "org.scalacheck" % "scalacheck_2.11" % "1.12.5" % "test",
  //  ScalaTest is test framework for scala
  // "org.scalatest" % "scalatest_2.11" % "3.0.1" % "test",
  //  Added as this is optional dependency for generating HTML reports in scalatest.
  "org.pegdown" % "pegdown" % "1.6.0" % "test",
  //  spark test framework.
  "com.holdenkarau" % "spark-testing-base_2.11" % "2.1.0_0.6.0" % "test",
  // mockito
  "org.powermock" % "powermock-api-mockito" % "1.7.4" % Test,
  "org.powermock" % "powermock-core" % "1.7.4" % Test,
  "org.powermock" % "powermock-module-junit4" % "1.7.4" % Test,
  "org.mockito" % "mockito-core" % "1.10.19" % Test,
  "com.novocode" % "junit-interface" % "0.11" % Test,
  // fastUtil efficient type specific collection library
  "it.unimi.dsi" % "fastutil" % "8.2.1"
)

// Create a default Scala style task to run with compile
(scalastyleConfig in Compile) := baseDirectory.value / "scalastyle-config.xml"
lazy val compileScalastyle = taskKey[Unit]("compileScalastyle")
compileScalastyle := org.scalastyle.sbt.ScalastylePlugin.scalastyle.in(Compile).toTask("").value
(compile in Compile) <<= (compile in Compile) dependsOn compileScalastyle

// Create a default Scala style task to run with tests
lazy val testScalastyle = taskKey[Unit]("testScalastyle")
testScalastyle := org.scalastyle.sbt.ScalastylePlugin.scalastyle.in(Test).toTask("").value
(test in Test) <<= (test in Test) dependsOn testScalastyle


// Configure Java source code style checking plugin.
checkstyleConfigLocation := CheckstyleConfigLocation.File("checkstyle-config.xml")
checkstyleSeverityLevel := Some(CheckstyleSeverityLevel.Error)
(checkstyle in Compile) <<= (checkstyle in Compile) triggeredBy (compile in Compile)
(checkstyle in Test) <<= (checkstyle in Test) triggeredBy (compile in Test)

// Specifying scalatest style traits for uniformity.
// All scala test classes should extend this style ONLY.
testOptions in Test += Tests.Argument(TestFrameworks.ScalaTest, "-y", "org.scalatest.PropSpec")
testOptions in Test += Tests.Argument(TestFrameworks.JUnit, "-v")
testOptions in Test ++= Seq(Tests.Argument(TestFrameworks.ScalaTest, "-o"),
  Tests.Argument(TestFrameworks.ScalaTest, "-h", "target/scala-2.11/scalatest-reports"))
testOptions in Test += Tests.Argument("-oD") // test execution time recording.
parallelExecution in Test := false
fork in Test := true

javaOptions ++= Seq("-Xms512M", "-Xmx2048M",
  "-XX:MaxPermSize=2048M", "-XX:+CMSClassUnloadingEnabled")

// Coverage settings
// Coverage is disabled by default to avoid Scoverage's runtime dependency in application jar.
// Enable coverage explicitly when needed. like,
//   sbt coverage clean test coverageReport
// Do not use coverage when publishing jar
// coverageEnabled := true
coverageMinimum := 70
coverageFailOnMinimum := false
coverageHighlighting := true

// Do not include scala librabries in assembly jar.
assemblyOption in assembly :=
  (assemblyOption in assembly).value.copy(includeScala = false)

// assembly name here should match to same generated by publishLocal.
assemblyJarName := "cml_" + scalaBinaryVersion.value + "-assembly.jar"

// addArtifact(artifact in (Compile, assembly), assembly)


// https://books.sonatype.com/nexus-book/reference/sbt.html
// SBT publish settings.
credentials += Credentials("Sonatype Nexus Repository Manager",
  "pp-nexus.office.yahoo.com",
  "yahooUser", "password")
publishTo <<= version { v: String =>
  val nexus = "http://pp-nexus.office.yahoo.com/"
  if (v.trim.endsWith("SNAPSHOT")) {
    Some("snapshots" at nexus + "content/repositories/yahoo-snapshots/")
  } else {
    Some("releases" at nexus + "content/repositories/yahoo-releases/")
  }
}

Answer 1

这里有两点需要注意。

1234563你自己的特质，并与之结合。

• Mocks 主要用于替换您自己的类/特征，而不是第 3 方的，因此，最好再次将调用包装到您自己的组件中（并进行集成测试为它）然后耦合到它，这将允许您轻松地模拟它。