Using with scala-2.13

[Vladislav Babin]

Hi,

I can't get junit test run with Scala 2.13.

I've generated a sample project from archetype:

mvn archetype:generate -DarchetypeGroupId=net.alchim31.maven -DarchetypeArtifactId=scala-archetype-simple

The generated project references Scala 2.12 and runs just fine. However when I upgrade to Scala 2.13

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>me.demo</groupId>
  <artifactId>demo-scala-01</artifactId>
  <version>1.0-SNAPSHOT</version>
  <name>${project.artifactId}</name>
  <description>My wonderfull scala app</description>
  <inceptionYear>2018</inceptionYear>

  <properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <encoding>UTF-8</encoding>
    <scala.version>2.13.1</scala.version>
    <scala.compat.version>2.13</scala.compat.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.scala-lang</groupId>
      <artifactId>scala-library</artifactId>
      <version>${scala.version}</version>
    </dependency>

    <!-- Test -->
    <dependency>
      <groupId>org.scalatest</groupId>
      <artifactId>scalatest_${scala.compat.version}</artifactId>
      <version>3.2.2</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.scalatestplus</groupId>
      <artifactId>junit-4-13_${scala.compat.version}</artifactId>
      <version>3.2.2.0</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
    <sourceDirectory>src/main/scala</sourceDirectory>
    <testSourceDirectory>src/test/scala</testSourceDirectory>
    <plugins>
      <plugin>
        <!-- see http://davidb.github.com/scala-maven-plugin -->
        <groupId>net.alchim31.maven</groupId>
        <artifactId>scala-maven-plugin</artifactId>
        <version>4.4.0</version>
        <executions>
          <execution>
            <goals>
              <goal>compile</goal>
              <goal>testCompile</goal>
            </goals>
            <configuration>
              <args>
                <arg>-dependencyfile</arg>
                <arg>${project.build.directory}/.scala_dependencies</arg>
              </args>
            </configuration>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>3.0.0-M4</version>
        <configuration>
          <!-- Tests will be run with scalatest-maven-plugin instead -->
          <skipTests>true</skipTests>
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.scalatest</groupId>
        <artifactId>scalatest-maven-plugin</artifactId>
        <version>2.0.0</version>
        <configuration>
          <reportsDirectory>${project.build.directory}/surefire-reports</reportsDirectory>
          <junitxml>.</junitxml>
          <filereports>TestSuiteReport.txt</filereports>
          <!-- Comma separated list of JUnit test class names to execute -->
          <jUnitClasses>samples.AppTest</jUnitClasses>
        </configuration>
        <executions>
          <execution>
            <id>test</id>
            <goals>
              <goal>test</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

I get the following error:

*** RUN ABORTED ***
  java.lang.ClassNotFoundException: org.scalatest.junit.JUnitWrapperSuite
  at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
  at org.scalatest.tools.Runner$.doRunRunRunDaDoRunRun(Runner.scala:1208)
  at org.scalatest.tools.Runner$.$anonfun$runOptionallyWithPassFailReporter$24(Runner.scala:993)
  at org.scalatest.tools.Runner$.$anonfun$runOptionallyWithPassFailReporter$24$adapted(Runner.scala:971)
  at org.scalatest.tools.Runner$.withClassLoaderAndDispatchReporter(Runner.scala:1480)
  at org.scalatest.tools.Runner$.runOptionallyWithPassFailReporter(Runner.scala:971)
  at org.scalatest.tools.Runner$.main(Runner.scala:775)
  at org.scalatest.tools.Runner.main(Runner.scala)
  ...

The cause is clear: scalatest library is looking for org.scalatest.junit.JUnitWrapperSuite but the class provided is org.scalatestplus.junit.JUnitWrapperSuite Yet I cannot figure out how to fix this issue. Can you provide a running example or an instruction?

Best regards,
Vladislav Babin

[Vladislav Babin]

Answering my own question: this helps resolve ClassNotFound exception

package org.scalatest.junit

class JUnitWrapperSuite(junitClassName: String, loader: ClassLoader)
  extends org.scalatestplus.junit.JUnitWrapperSuite(junitClassName, loader) {
}

Hope that project maintainers could give a better advice though...