JUnit Task

## JUnit

### Description

This task runs tests from the JUnit testing framework. The latest version of the framework can be found at http://www.junit.org. This task has been tested with JUnit 3.0 up to JUnit 3.8.2; it won't work with versions prior to JUnit 3.0. It also works with JUnit 4.0, including "pure" JUnit 4 tests using only annotations and no `JUnit4TestAdapter`.

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

Note: You must have `junit.jar` available. You can do one of:

1. Put both `junit.jar` and `ant-junit.jar` in `ANT_HOME/lib`.
2. Do not put either in `ANT_HOME/lib`, and instead include their locations in your `CLASSPATH` environment variable.
3. Add both JARs to your classpath using `-lib`.
4. Specify the locations of both JARs using a `<classpath>` element in a `<taskdef>` in the build file.
5. Leave `ant-junit.jar` in its default location in `ANT_HOME/lib` but include `junit.jar` in the `<classpath>` passed to `<junit>`. (since Ant 1.7)

See the FAQ for details.

Tests are defined by nested `test` or `batchtest` tags (see nested elements).

### Parameters

Attribute | Description | Required
printsummary | Print one-line statistics for each testcase. Can take the values `on`, `off`, and `withOutAndErr`. `withOutAndErr` is the same as `on` but also includes the output of the test as written to `System.out` and `System.err`. | No; default is `off`.
fork | Run the tests in a separate VM. | No; default is `off`.
forkmode | Controls how many Java Virtual Machines get created if you want to fork some tests. Possible values are "perTest" (the default), "perBatch" and "once". "once" creates only a single Java VM for all tests while "perTest" creates a new VM for each TestCase class. "perBatch" creates a VM for each nested `<batchtest>` and one collecting all nested `<test>`s. Note that only tests with the same settings of `filtertrace`, `haltonerror`, `haltonfailure`, `errorproperty` and `failureproperty` can share a VM, so even if you set `forkmode` to "once", Ant may have to create more than a single Java VM. This attribute is ignored for tests that don't get forked into a new Java VM. since Ant 1.6.2 | No; default is `perTest`.
haltonerror | Stop the build process if an error occurs during the test run. | No; default is `off`.
errorproperty | The name of a property to set in the event of an error. | No
haltonfailure | Stop the build process if a test fails (errors are considered failures as well). | No; default is `off`.
failureproperty | The name of a property to set in the event of a failure (errors are considered failures as well). | No.
filtertrace | Filter out Junit and Ant stack frames from error and failure stack traces. | No; default is `on`.
timeout | Cancel the individual tests if they don't finish in the given time (measured in milliseconds). Ignored if `fork` is disabled. When running multiple tests inside the same Java VM (see forkMode), timeout applies to the time that all tests use together, not to an individual test. | No
maxmemory | Maximum amount of memory to allocate to the forked VM. Ignored if `fork` is disabled. Note: If you get `java.lang.OutOfMemoryError: Java heap space` in some of your tests then you need to raise the size like `maxmemory="128m"` | No
jvm | The command used to invoke the Java Virtual Machine, default is 'java'. The command is resolved by `java.lang.Runtime.exec()`. Ignored if `fork` is disabled. | No; default is `java`.
dir | The directory in which to invoke the VM. Ignored if `fork` is disabled. | No
newenvironment | Do not propagate the old environment when new environment variables are specified. Ignored if `fork` is disabled. | No; default is `false`.
includeantruntime | Implicitly add the Ant classes required to run the tests and JUnit to the classpath in forked mode. | No; default is `true`.
showoutput | Send any output generated by tests to Ant's logging system as well as to the formatters. By default only the formatters receive the output. | No
outputtoformatters | Since Ant 1.7.0. Send any output generated by tests to the test formatters. This is "true" by default. | No
tempdir | Where Ant should place temporary files. Since Ant 1.6. | No; default is the project's base directory.
reloading | Whether or not a new classloader should be instantiated for each test case. Ignore if `fork` is set to true. Since Ant 1.6. | No; default is `true`.
clonevm | If set to true true, then all system properties and the bootclasspath of the forked Java Virtual Machine will be the same as those of the Java VM running Ant. Default is "false" (ignored if fork is disabled). since Ant 1.7 | No
logfailedtests | When Ant executes multiple tests and doesn't stop on errors or failures it will log a "FAILED" message for each failing test to its logging system. If you set this option to false, the message will not be logged and you have to rely on the formatter output to find the failing tests. since Ant 1.8.0 | No

By using the `errorproperty` and `failureproperty` attributes, it is possible to perform setup work (such as starting an external server), execute the test, clean up, and still fail the build in the event of a failure.

The `filtertrace` attribute condenses error and failure stack traces before reporting them. It works with both the plain and XML formatters. It filters out any lines that begin with the following string patterns:

       "junit.framework.TestCase"
       "junit.framework.TestResult"
       "junit.framework.TestSuite"
       "junit.framework.Assert."
       "junit.swingui.TestRunner"
       "junit.awtui.TestRunner"
       "junit.textui.TestRunner"
       "java.lang.reflect.Method.invoke("
       "sun.reflect."
       "org.apache.tools.ant."
       "org.junit."
       "junit.framework.JUnit4TestAdapter"

### Nested Elements

The `<junit>` task supports a nested `<classpath>` element that represents a PATH like structure.

As of Ant 1.7, this classpath may be used to refer to `junit.jar` as well as your tests and the tested code.

#### jvmarg

If `fork` is enabled, additional parameters may be passed to the new VM via nested `<jvmarg>` elements. For example:

    <junit fork="yes">
      <jvmarg value="-Djava.compiler=NONE"/>
      ...
    </junit>

would run the test in a VM without JIT.

`<jvmarg>` allows all attributes described in Command-line Arguments.

#### sysproperty

Use nested `<sysproperty>` elements to specify system properties required by the class. These properties will be made available to the VM during the execution of the test (either ANT's VM or the forked VM, if `fork` is enabled). The attributes for this element are the same as for environment variables.

    <junit fork="no">
      <sysproperty key="basedir" value="${basedir}"/>
      ...
    </junit>

would run the test in ANT's VM and make the `basedir` property available to the test.

#### syspropertyset

You can specify a set of properties to be used as system properties with syspropertysets.

since Ant 1.6.

#### env

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

Settings will be ignored if `fork` is disabled.

#### bootclasspath

The location of bootstrap class files can be specified using this PATH like structure - will be ignored if fork is not `true` or the target VM doesn't support it (i.e. Java 1.1).

since Ant 1.6.

#### permissions

Security permissions can be revoked and granted during the execution of the class via a nested permissions element. For more information please see permissions

Settings will be ignored if fork is enabled.

since Ant 1.6.

#### assertions

You can control enablement of Java 1.4 assertions with an `<assertions>` subelement.

Assertion statements are currently ignored in non-forked mode.

since Ant 1.6.

#### formatter

The results of the tests can be printed in different formats. Output will always be sent to a file, unless you set the `usefile` attribute to `false`. The name of the file is determined by the name of the test and can be set by the `outfile` attribute of `<test>`.

There are four predefined formatters - one prints the test results in XML format, the other emits plain text. The formatter named `brief` will only print detailed information for testcases that failed, while `plain` gives a little statistics line for all test cases. Custom formatters that need to implement `org.apache.tools.ant.taskdefs.optional.junit.JUnitResultFormatter` can be specified.

If you use the XML formatter, it may not include the same output that your tests have written as some characters are illegal in XML documents and will be dropped.

The fourth formatter named `failure` (since Ant 1.8.0) collects all failing `testXXX()` methods and creates a new `TestCase` which delegates only these failing methods. The name and the location can be specified via Java System property or Ant property `ant.junit.failureCollector`. The value has to point to the directory and the name of the resulting class (without suffix). It defaults to java-tmp-dir/FailedTests.

Attribute | Description | Required
type | Use a predefined formatter (either `xml`, `plain`, `brief` or `failure`). | Exactly one of these.
classname | Name of a custom formatter class.
extension | Extension to append to the output filename. | Yes, if `classname` has been used.
usefile | Boolean that determines whether output should be sent to a file. | No; default is `true`.
if | Only use formatter if the named property is set. | No; default is `true`.
unless | Only use formatter if the named property is not set. | No; default is `true`.

#### test

Defines a single test class.

Attribute | Description | Required
name | Name of the test class. | Yes
fork | Run the tests in a separate VM. Overrides value set in `<junit>`. | No
haltonerror | Stop the build process if an error occurs during the test run. Overrides value set in `<junit>`. | No
errorproperty | The name of a property to set in the event of an error. Overrides value set in `<junit>`. | No
haltonfailure | Stop the build process if a test fails (errors are considered failures as well). Overrides value set in `<junit>`. | No
failureproperty | The name of a property to set in the event of a failure (errors are considered failures as well). Overrides value set in `<junit>`. | No
filtertrace | Filter out Junit and Ant stack frames from error and failure stack traces. Overrides value set in `<junit>`. | No; default is `on`.
todir | Directory to write the reports to. | No; default is the current directory.
outfile | Base name of the test result. The full filename is determined by this attribute and the extension of `formatter`. | No; default is `TEST-`name, where name is the name of the test specified in the `name` attribute.
if | Only run test if the named property is set. | No
unless | Only run test if the named property is not set. | No

Tests can define their own formatters via nested `<formatter>` elements.

#### batchtest

Define a number of tests based on pattern matching.

`batchtest` collects the included resources from any number of nested Resource Collections. It then generates a test class name for each resource that ends in `.java` or `.class`.

Any type of Resource Collection is supported as a nested element, prior to Ant 1.7 only `<fileset>` has been supported.

Attribute | Description | Required
fork | Run the tests in a separate VM. Overrides value set in `<junit>`. | No
haltonerror | Stop the build process if an error occurs during the test run. Overrides value set in `<junit>`. | No
errorproperty | The name of a property to set in the event of an error. Overrides value set in `<junit>`. | No
haltonfailure | Stop the build process if a test fails (errors are considered failures as well). Overrides value set in `<junit>`. | No
failureproperty | The name of a property to set in the event of a failure (errors are considered failures as well). Overrides value set in `<junit>` | No
filtertrace | Filter out Junit and Ant stack frames from error and failure stack traces. Overrides value set in `<junit>`. | No; default is `on`.
todir | Directory to write the reports to. | No; default is the current directory.
if | Only run tests if the named property is set. | No
unless | Only run tests if the named property is not set. | No

Batchtests can define their own formatters via nested `<formatter>` elements.

### Forked tests and `tearDown`

If a forked test runs into a timeout, Ant will terminate the Java VM process it has created, which probably means the test's `tearDown` method will never be called. The same is true if the forked VM crashes for some other reason.

Starting with Ant 1.8.0, a special formatter is distributed with Ant that tries to load the testcase that was in the forked VM and invoke that class' `tearDown` method. This formatter has the following limitations:

- It runs in the same Java VM as Ant itself, this is a different Java VM than the one that was executing the test and it may see a different classloader (and thus may be unable to load the tast class).
- It cannot determine which test was run when the timeout/crash occured if the forked VM was running multiple test. I.e. the formatter cannot work with any `forkMode` other than `perTest` and it won't do anything if the test class contains a `suite()` method.

If the formatter recognizes an incompatible `forkMode` or a `suite` method or fails to load the test class it will silently do nothing.

The formatter doesn't have any effect on tests that were not forked or didn't cause timeouts or VM crashes.

To enable the formatter, add a `formatter` like

    <formatter classname="org.apache.tools.ant.taskdefs.optional.junit.TearDownOnVmCrash"
               usefile="false"/>

to your `junit` task.

### Examples

    <junit>
      <test name="my.test.TestCase"/>
    </junit>

Runs the test defined in `my.test.TestCase` in the same VM. No output will be generated unless the test fails.

    <junit printsummary="yes" fork="yes" haltonfailure="yes">
      <formatter type="plain"/>
      <test name="my.test.TestCase"/>
    </junit>

Runs the test defined in `my.test.TestCase` in a separate VM. At the end of the test, a one-line summary will be printed. A detailed report of the test can be found in `TEST-my.test.TestCase.txt`. The build process will be stopped if the test fails.

    <junit printsummary="yes" haltonfailure="yes">
      <classpath>
        <pathelement location="${build.tests}"/>
        <pathelement path="${java.class.path}"/>
      </classpath>

      <formatter type="plain"/>

      <test name="my.test.TestCase" haltonfailure="no" outfile="result">
        <formatter type="xml"/>
      </test>

      <batchtest fork="yes" todir="${reports.tests}">
        <fileset dir="${src.tests}">
          <include name="**/*Test*.java"/>
          <exclude name="**/AllTests.java"/>
        </fileset>
      </batchtest>
    </junit>

Runs `my.test.TestCase` in the same VM, ignoring the given CLASSPATH; only a warning is printed if this test fails. In addition to the plain text test results, for this test a XML result will be output to `result.xml`. Then, for each matching file in the directory defined for `${src.tests}` a test is run in a separate VM. If a test fails, the build process is aborted. Results are collected in files named `TEST-`name`.txt` and written to `${reports.tests}`.

    <target name="test">
        <property name="collector.dir" value="${build.dir}/failingTests"/>
        <property name="collector.class" value="FailedTests"/>
        <!-- Delete 'old' collector classes -->
        <delete>
            <fileset dir="${collector.dir}" includes="${collector.class}*.class"/>
        </delete>
        <!-- compile the FailedTests class if present -->
        <javac srcdir="${collector.dir}" destdir="${collector.dir}"/>
        <available file="${collector.dir}/${collector.class}.class" property="hasFailingTests"/>
        <junit haltonerror="false" haltonfailure="false">
            <sysproperty key="ant.junit.failureCollector" value="${collector.dir}/${collector.class}"/>
            <classpath>
                <pathelement location="${collector.dir}"/>
            </classpath>
            <batchtest todir="${collector.dir}" unless="hasFailingTests">
                <fileset dir="${collector.dir}" includes="**/*.java" excludes="**/${collector.class}.*"/>
                <!-- for initial creation of the FailingTests.java -->
                <formatter type="failure"/>
                <!-- I want to see something ... -->
                <formatter type="plain" usefile="false"/>
            </batchtest>
            <test name="FailedTests" if="hasFailingTests">
                <!-- update the FailingTests.java -->
                <formatter type="failure"/>
                <!-- again, I want to see something -->
                <formatter type="plain" usefile="false"/>
            </test>
        </junit>
    </target>

On the first run all tests are collected via the `<batchtest/>` element. It's `plain` formatter shows the output on the console. The `failure` formatter creates a java source file in `${build.dir}/failingTests/FailedTests.java` which extends `junit.framework.TestCase` and returns from a `suite()` method a test suite for the failing tests.
On a second run the collector class exists and instead of the `<batchtest/>` the single `<test/>` will run. So only the failing test cases are re-run. The two nested formatters are for displaying (for the user) and for updating the collector class.