JUnitLauncher

Description

This task allows tests to be launched and run using the JUnit 5 framework.

JUnit 5 introduced a newer set of APIs to write and launch tests. It also introduced the concept of test engines. Test engines decide which classes are considered as testcases and how they are executed. JUnit 5 supports running tests that have been written using JUnit 4 constructs as well as tests that have been written using JUnit 5 constructs. For more details about JUnit 5 itself, please refer to the JUnit 5 project's documentation at https://junit.org/junit5/.

The goal of this junitlauncher task is to allow launching the JUnit 5 test launcher and building the test requests so that the selected tests can then be parsed and executed by the test engine(s) supported by JUnit 5. This task in itself does not understand what a test case is nor does it execute the tests itself.

This task captures testoutput and configuration data inside of the temporary directory.

Note: This task depends on external libraries not included in the Apache Ant distribution. See Library Dependencies for more information.

Note: You must have the necessary JUnit 5 libraries in the classpath of the tests. At the time of writing this documentation, the list of JUnit 5 platform libraries that are necessary to run the tests are:

• junit-platform-commons.jar
• junit-platform-engine.jar
• junit-platform-launcher.jar
• opentest4j.jar

Depending on the test engine(s) that you want to use in your tests, you will further need the following libraries in the classpath

For junit-vintage engine:

• junit-vintage-engine.jar
• junit.jar (JUnit 4.x version)

For junit-jupiter engine:

• junit-jupiter-api.jar
• junit-jupiter-engine.jar

To have these in the test classpath, you can follow either of the following approaches:

• Recommended approach since Ant 1.10.6: Place the ant-junitlauncher.jar in ANT_HOME/lib directory and use the nested <classpath> element to specify the location of the the rest of the JUnit specific jars (noted above). Please read the using classpath element section for more details.
• OR Put all these relevant jars along with the ant-junitlauncher.jar in ANT_HOME/lib directory
• OR Put ant-junitlauncher.jar in the ANT_HOME/lib directory and include all other relevant jars in the classpath by passing them as a -lib option, while invoking Ant

Tests are defined by nested elements like test, testclasses tags (see nested elements).

Parameters

Nested Elements

classpath

The nested <classpath> element that represents a PATH like structure can be used to configure the task to use this classpath for finding and running the tests. This classpath will be used for:

• Finding the test classes to execute
• Finding test engines that run the tests
• If configured to do so, finding all necessary JUnit libraries

If the classpath element isn't configured for the task, then the classpath of Ant itself will be used for finding the test classes and the JUnit libraries.

Below is an example of setting up the classpath to include the Jupiter test engine and the JUnit platform libraries during the execution of the tests.

<project>

    <property name="output.dir" value="${basedir}/build"/>
    <property name="src.test.dir" value="${basedir}/src/test"/>
    <property name="build.classes.dir" value="${output.dir}/classes"/>

    <target name="init">
        <mkdir dir="${output.dir}"/>
    </target>

    <path id="junit.platform.libs.classpath">
        <fileset dir="${basedir}/src/lib/junit-platform/"/>
    </path>

    <path id="junit.engine.jupiter.classpath">
        <fileset dir="${basedir}/src/lib/jupiter/"/>
    </path>

    <target name="compile-test" depends="init">
        <mkdir dir="${build.classes.dir}"/>
        <javac srcdir="${src.test.dir}"
           destdir="${build.classes.dir}">
           <!-- our tests only need JUnit Jupiter engine
           libraries in our compile classpath for the tests -->
           <classpath refid="junit.engine.jupiter.classpath"/>
        </javac>
    </target>

    <target name="test" depends="compile-test">
        <junitlauncher>
            <!-- include the JUnit platform related libraries
            required to run the tests -->
            <classpath refid="junit.platform.libs.classpath"/>

            <!-- include the JUnit Jupiter engine libraries -->
            <classpath refid="junit.engine.jupiter.classpath"/>

            <classpath>
                <!-- the test classes themselves -->
                <pathelement location="${build.classes.dir}"/>
            </classpath>
            <testclasses outputdir="${output.dir}">
                <fileset dir="${build.classes.dir}"/>
                <listener type="legacy-brief" sendSysOut="true"/>
                <listener type="legacy-xml" sendSysErr="true" sendSysOut="true"/>

            </testclasses>
        </junitlauncher>
    </target>
</project>
    

In the example above,

• The src/lib/jupiter directory is expected to contain the Jupiter test engine related jars (which have been listed in an earlier section of this document).
• The src/lib/junit-platform directory is expected to contain the JUnit platform jars (which have been listed in an earlier section of this document)

In the test target we use the classpath nested element to point to the junit.engine.jupiter.classpath and junit.platform.libs.classpath containing those jars. In this test target we also use another classpath element to point to the location containing our test classes. If required, all these classpaths can be combined into one.

listener

The junitlauncher task can be configured with listener(s) to listen to test execution events (such as a test execution starting, completing etc...). The listener is expected to be a class which implements the org.junit.platform.launcher.TestExecutionListener. This TestExecutionListener interface is an API exposed by the JUnit 5 platform APIs and isn't specific to Ant. As such, you can use any existing implementation of TestExecutionListener in this task.

Test result formatter

junitlauncher provides a way where the test execution results can be formatted and presented in a way that's customizable. The task allows for configuring test result formatters, through the use of listener element. As noted previously, the listener element expects the listener to implement the org.junit.platform.launcher.TestExecutionListener interface. Typically, result formatters need a bit more configuration details to be fed to them, during the test execution—details like where to write out the formatted result. Any such listener can optionally implement the org.apache.tools.ant.taskdefs.optional.junitlauncher.TestResultFormatter interface. This interface is specific to Ant junitlauncher task and it extends the org.junit.platform.launcher.TestExecutionListener interface

The junitlauncher task comes with the following pre-defined test result formatter types:

• legacy-plain : This formatter prints a short statistics line for all test cases.
• legacy-brief : This formatter prints information for tests that failed or were skipped.
• legacy-xml : This formatter prints statistics for the tests in XML format.

Note: Each of these formatters named legacy try to format the results similar to what the junit task's formatters used to do. Furthermore, the legacy-xml formatter generates the XML to comply with the same schema that the junit task's XML formatter used to follow. As a result, the XML generated by this formatter, can be used as-is by the junitreport task.

The listener element supports the following attributes:

test

Defines a single test class.

Tests can define their own listeners via nested listener elements.

The fork nested element can be used to run the test in a newly forked JVM.

testclasses

Define a number of tests based on pattern matching.

testclasses collects the included resources from any number of nested Resource Collections. It then selects each resource whose name ends in .class. These classes are then passed on to the JUnit 5 platform for it to decide and run them as tests.

testclasses can define their own listeners via nested listener elements.

The fork nested element can be used to run the tests in a newly forked JVM. All tests that are part of this testclasses element will run in one single instance of the newly forked JVM.

fork

Since Ant 1.10.6

jvmarg

Additional JVM arguments may be passed to the forked JVM via the jvmarg elements. For example:

    <fork ...>
      <jvmarg value="-Dfoo=bar"/>
      ...
    </fork>
    

jvmarg allows all attributes described in Command-line Arguments

sysproperty

The sysproperty elements allow passing Java system properties to the forked JVM:

    <fork>
        <sysproperty key="greeting" value="hello world"/>
    ...
    </fork>
    

The attributes for this element are the same as for environment variables

syspropertyset

You can specify a set of properties to be used as system properties with syspropertyset(s)

env

It is possible to specify environment variables to pass to the forked JVM via nested env elements. For a description of the env element's attributes, see the description in the exec task.

modulepath

The location of Java modules can be specified using the modulepath element, which is a path-like structure.

<fork>
  <modulepath>
    <pathelement location="lib"/>
    <pathelement location="dist/test.jar"/>
  </modulepath>
  ...
</fork>

upgrademodulepath

The location of Java modules, that replace upgradeable modules in the runtime, can be specified using the upgrademodulepath element, which is a path-like structure.

Examples

Launch the JUnit 5 platform to run the org.myapp.SimpleTest test

<path id="test.classpath">
    ...
</path>

<junitlauncher>
    <classpath refid="test.classpath"/>
    <test name="org.myapp.SimpleTest"/>
</junitlauncher>

Launch the JUnit 5 platform to run the org.myapp.SimpleTest and the org.myapp.AnotherTest tests. The build process will be stopped if any test, in the org.myapp.SimpleTest, fails.

<junitlauncher>
    <classpath refid="test.classpath"/>
    <test name="org.myapp.SimpleTest" haltOnFailure="true"/>
    <test name="org.myapp.AnotherTest"/>
</junitlauncher>

Launch the JUnit 5 platform to run only the testFoo and testBar methods of the org.myapp.SimpleTest test class.

<junitlauncher>
    <classpath refid="test.classpath"/>
    <test name="org.myapp.SimpleTest" methods="testFoo, testBar"/>
</junitlauncher>

Select any .class files that match the org/example/**/tests/**/ fileset filter, under the ${build.classes.dir} and passes those classes to the JUnit 5 platform for execution as tests.

<junitlauncher>
    <classpath refid="test.classpath"/>

    <testclasses outputdir="${output.dir}">
        <fileset dir="${build.classes.dir}">
            <include name="org/example/**/tests/**/"/>
        </fileset>
    </testclasses>
</junitlauncher>

Select any .class files that match the org/example/**/tests/**/ fileset filter, under the ${build.classes.dir} and pass those classes to the JUnit 5 platform for execution as tests. Test results will be written out to the ${output.dir} by the legacy-xml and legacy-plain formatters, in separate files. Furthermore, both the legacy-xml and the legacy-plain listeners, above, are configured to receive the standard output content generated by the tests. The legacy-xml listener is configured to receive standard error content as well.

<junitlauncher>
    <classpath refid="test.classpath"/>

    <testclasses outputdir="${output.dir}">
        <fileset dir="${build.classes.dir}">
            <include name="org/example/**/tests/**/"/>
        </fileset>
        <listener type="legacy-xml" sendSysOut="true" sendSysErr="true"/>
        <listener type="legacy-plain" sendSysOut="true" />
    </testclasses>
</junitlauncher>