PitMP: Maven plugin to handle multi module projects for PiTest

Table of contents

• Quick start
• What is PitMP?
• How does PitMP work?
• PitMP Output
• Running PitMP on your project
• Releases
• Tested on

Quick start

• on command line

  • Compile your project

  mvn install
  

  • and run PIT

  mvn eu.stamp-project:pitmp-maven-plugin:run
  

  • or run Descartes

  mvn eu.stamp-project:pitmp-maven-plugin:descartes
  

• with Maven
  Modify your pom.xml,

  • for PIT include:

      <plugin>
        <groupId>eu.stamp-project</groupId>
        <artifactId>pitmp-maven-plugin</artifactId>
        <version>1.3.7</version>
      </plugin>
  

  • and for Descartes include:

      <plugin>
        <groupId>eu.stamp-project</groupId>
        <artifactId>pitmp-maven-plugin</artifactId>
        <version>1.3.7</version>
        <configuration>
          <mutationEngine>descartes</mutationEngine>
        </configuration>
      </plugin>
  

Note

PitMP works only from the top level directory of your project.  
"cd <my_directory> ; mvn eu.stamp-project:pitmp-maven-plugin:run" will NOT work.

c.f. properties targetModules and skippedModules to specify in which directories you want to run PitMP.

What is PitMP?

PitMP (PIT for Multi-module Project) is a Maven plugin able to run PIT on multi-module projects. PIT is a mutation testing system for Java applications, which allows you to evaluate the quality of your test suites.

To know more about PIT: http://pitest.org

How does PitMP work?

PIT takes a test suite, a set of classes to be mutated and a set of mutation operators and computes a line coverage and a mutation coverage:

PIT mutates only the classes defined in the same module than the test suite:

PitMP runs PIT on every test suite, mutating classes of all dependencies of modules located in the same project tree:

then:

etc...

PitMP just extends PIT, it doesn't rewrite any feature, so all PIT's properties can be used. PitMP runs test suite as PIT does, just extending the list of classes to be mutated to the whole project tree, instead of mutating only the classes of the test suite module.

PitMP Output

PIT produces a report that includes:

• a summary of line coverage and mutation coverage scores:
• a detail report for each class combining line coverage and mutation coverage information:
  Light green shows line coverage, dark green shows mutation coverage.
  Light pink show lack of line coverage, dark pink shows lack of mutation coverage.

Running PitMP on your project

• Go to the project on which you want to apply PIT

• Compile your project

mvn install

• Run PIT on your multi module project :-)

mvn eu.stamp-project:pitmp-maven-plugin:run

Install the plugin for releases earlier than 1.1.4

Since 1.1.4 PitMP is available on Maven Central, so this step is required only for releases before 1.1.4.

git clone https://github.com/STAMP-project/pitmp-maven-plugin.git
cd pitmp-maven-plugin
mvn install

Configure PitMP

You can configure your project in the root pom.xml, in the section <plugins>:

  <plugin>
    <groupId>eu.stamp</groupId>
    <artifactId>pitmp-maven-plugin</artifactId>
    <version>release.you.want</version>
    <!-- List all the packages of the project that contain classes you want
         to be mutated.
         All PIT's properties can be used.
    -->
    <configuration>
      <targetClasses>
        <param>a.package.of.classes*</param>
        <param>another.package.of.classes*</param>
      </targetClasses>
    </configuration>
  </plugin>

PitMP properties

• targetModules: to run PIT only on specified modules, this attribute filters directories where to run PIT, not classes to be mutated
  You can use the property "targetModules" in the pom.xml:

          <targetModules>
            <param>yourFirstModule</param>
            <param>anotherModule</param>
          </targetModules>
  

  or on the command line, use:

  mvn "-DtargetModules=yourFirstModule,anotherModule" pitmp:run
  

  Running PitMP from a module directory will NOT work.

• skippedModules: to skip specified modules when running PIT, this attribute filters directories where to run PIT, not classes to be mutated
  You can use the property "skippedModules" in the pom.xml:

          <skippedModules>
            <param>aModuleToSkip</param>
            <param>anotherModuleToSkip</param>
          </skippedModules>
  

  or on the command line, use:

  mvn "-DtargetModules=aModuleToSkip,anotherModuleToSkip" pitmp:run
  

• targetDependencies: take only into account classes of targetDependencies, i.e. only code in targetDependencies will be mutated; it impacts PIT's targetClasses
  Note that only targetDependencies shall contains only modules of the project

• ignoredDependencies: ignore classes of ignoredDependencies, i.e. code in targetDependencies will not be mutated; it impacts PIT's targetClasses If a module is both in targetDependencies and ignoredDependencies, it will be ignored.

• continueFromModule: to run PIT starting from a given project (because continuing an aborted execution with Maven -rf is not working)

          <continueFromModule>aModule</continueFromModule>
  

Running Descartes

If you want to run Descartes:

mvn eu.stamp-project:pitmp-maven-plugin:descartes

If you want to configure Descartes, add to your root project pom.xml, in the section <plugins>:

  <plugin>
    <groupId>eu.stamp</groupId>
    <artifactId>pitmp-maven-plugin</artifactId>
    <version>release.you.want</version>
    <!-- list all the packages of the project that contain classes you want to be mutated    -->
    <configuration>
      <targetClasses>
        <param>a.package.of.classes*</param>
        <param>another.package.of.classes*</param>
      </targetClasses>
      <mutationEngine>descartes</mutationEngine>
    </configuration>
  </plugin>

For complete instructions about Descartes see the Descartes github.

For an example of multi module project using PitMP see the dnoo github.

Check Pseudo/Partially Tested Methods number

If you want to check the number of Pseudo Tested Methods and/or Partially Tested Methods, you can add specific thresholds pseudoTestedThreshold and/or partiallyTestedThreshold in the configuration:

  <plugin>
    <groupId>eu.stamp</groupId>
    <artifactId>pitmp-maven-plugin</artifactId>
    <version>release.you.want</version>
    <configuration>
      <!-- Check Pseudo/Partially Tested Methods -->
      <pseudoTestedThreshold>1</pseudoTestedThreshold>
      <partiallyTestedThreshold>1</partiallyTestedThreshold>
      <targetClasses>
        <param>a.package.of.classes*</param>
        <param>another.package.of.classes*</param>
      </targetClasses>
      <mutationEngine>descartes</mutationEngine>
    </configuration>
  </plugin>

Break the build upon threshold crossing (mutation score or line coverage)

The plugin can break the build, when the mutation score and/or line coverage is considered too poor. The example below breaks the build if mutation score is less than 40% or line coverage less than 60 %, according to "mutationThreshold" and "coverageThreshold" options:

  <plugin>
    <groupId>eu.stamp-project</groupId>
    <artifactId>pitmp-maven-plugin</artifactId>
    <version>release.you.want</version>
    <configuration>
      <mutationEngine>descartes</mutationEngine>
      <skip>false</skip>
      <failWhenNoMutations>false</failWhenNoMutations>
      <mutationThreshold>40</mutationThreshold>
      <coverageThreshold>60</coverageThreshold>
    </configuration>
  </plugin>

Notes concerning additional options:

• "skip" option (default false): if set to true, the whole plugin execution is skipped (this can be parameterized).
• "failWhenNoMutations" option (default true): if set to true, the build fails when there is no mutation.

Releases

• pitmp-maven-plugin-1.3.7

  • Dependency on Descartes v1.2.5

• pitmp-maven-plugin-1.3.6

  • Dependency on Descartes v1.2.4
  • Tested with PIT v1.4.2, Descartes v1.2.4, JUnit4 and JUnit5
  • Fixed issues: #19,
  • Updating reference files for automated tests (missing automated results checking)
  • Tested on Ubuntu 18.04.1 LTS

• pitmp-maven-plugin-1.3.5

  • Dependency on Descartes v1.3.4
  • Tested with PIT v1.4.2, Descartes v1.3.4, JUnit4 and JUnit5
  • Adding properties targetDependencies, ignoredDependencies and continueFromModule
  • Adding a module with no test in automated test suite
  • Running automated tests with XML report option and adding reference files (missing automated results checking)
  • Fixed issues: #16, #17, #20, #21, #22, #27,
  • Tested on Ubuntu 18.04.1 LTS

• pitmp-maven-plugin-1.3.4

  • Dependency on Descartes v1.2.4 (hotfix for a regression in 1.3.3)
  • Tested with PIT v1.4.0, Descartes v1.2.4, JUnit4 and JUnit5
  • Tested on Ubuntu 16.04.4 LTS

• pitmp-maven-plugin-1.3.3

  • Dependency on Descartes v1.2.3
  • Tested with PIT v1.4.0, Descartes v1.2.3, JUnit4 and JUnit5
  • Tested on Ubuntu 16.04.4 LTS

• pitmp-maven-plugin-1.3.2

  • Dependency on Descartes v1.2.2
  • Tested with PIT v1.4.0, Descartes v1.2.2, JUnit4 and JUnit5
  • Fixed issues: #13
  • Tested on Ubuntu 16.04.4 LTS

• pitmp-maven-plugin-1.3.1

  • Dependency on Descartes v1.2.1
  • Tested with PIT v1.4.0 and Descartes v1.2.1
  • Tested on Ubuntu 16.04.4 LTS

• pitmp-maven-plugin-1.3.0

  • Adding a goal 'descartes'
  • Dependency on Descartes v1.2
  • Tested with PIT v1.4.0 and Descartes v1.2
  • Tested on Ubuntu 16.04.4 LTS

• pitmp-maven-plugin-1.2.0

  • Tested with PIT v1.4.0 and Descartes v1.2
  • Tested on Ubuntu 16.04.4 LTS

• pitmp-maven-plugin-1.1.6

  • Tested with PIT v1.3.2
  • Fixed issues: #10
  • Tested on Ubuntu 16.04.4 LTS

• pitmp-maven-plugin-1.1.5

  • Tested with PIT v1.3.2
  • Fixed issues: #6, #7, #9 (Duplicate #6)
  • Add automatic tests (verify_pitmp.sh)
  • Limitation: #10
  • Tested on Ubuntu 16.04.4 LTS

• v1.1.0, pitmp-maven-plugin-1.1.4

  • Tested with PIT v1.3.1
  • Tested on Ubuntu 16.04.4 LTS

• v1.0.1

  • Tested with PIT v1.2.0 and Descartes v0.2-SNAPSHOT
  • Tested with PIT v1.2.3
  • Tested on Ubuntu 16.04.4 LTS

Feedbacks are welcome ! :-)