plugin-maven

The Decycle Maven Plugin adds verification goals to the Maven build that check for package and slice cycles on the classes of a Maven project.

Requirements: Maven ≥ 3.3.1, Java ≥ 11

Installation

Add the decycle plugin to the build section of your pom.xml:

<build>
  <plugins>
    <plugin>
        <groupId>de.obqo.decycle</groupId>
        <artifactId>decycle-maven-plugin</artifactId>
        <version>...</version>
        <executions>
          <execution>
            <goals>
              <goal>check</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <!-- see below -->
        </configuration>
    </plugin>
  </plugins>
</build>

The decycle plugin provides the goals decycle:check, decycle:checkMain, and decycle:checkTest.

Running

The above base configuration will execute the goal decycle:check automatically in the verify phase of the maven lifecycle. Decycle will check the main and the test classes separately, and it will create a dependency report for each check. These reports can be found in the reporting directory, i.e. typically the two reports are target/site/decycle/main.html and target/site/decycle/test.html. If it detects violations (i.e. package cycles) then the build will fail by default (however, this behavior can be adjusted, see ignoreFailures below in Configuration).

The two goals decycle:checkMain and decycle:checkTest are intended to be invoked as single goals (e.g. via mvn decycle:checkMain). They will first compile the sources and perform the decycle check afterward. They may be executed after fixing violations detected by decycle. (Note: running decycle:check in contrast will not automatically recompile the sources.)

The execution of the decycle goals might be skipped by passing the following properties to maven (e.g. via mvn verify -Ddecycle.skip):

• decycle.skip will skip decycle checks completely
• decycle.skipMain will skip the decycle check for the main classes
• decycle.skipTest will skip the decycle check for the test classes

Setting the property decycle.ignoreFailures will ignore any failures detected by decycle (but it will still generate the reports).

Configuration

Within the configuration element of the plugin (see Installation above) the following parameters can be defined:

<configuration>
  <including>org.example.includes.**, ...</including>
  <excluding>org.example.excludes.**, ...</excluding>
  <ignoring>
    <dependency>
      <from>org.examples.from.Example</from>
      <to>org.examples.to.**</to>
    </dependency>
  </ignoring>
  <slicings>
    <slicing>
      <name>module</name>
      <patterns>org.example.{*}.**, ...</patterns>
      <constraints>
        <allow>a, b, ...</allow>
        <allow-direct>
          <any-of>x</any-of>
          <any-of>y, z</any-of>
        </allow-direct>
      </constraints>
    </slicing>
  </slicings>
  <ignoreFailures>false</ignoreFailures>
  <skip>false</skip>
  <skipMain>false</skipMain>
  <skipTest>false</skipTest>
  <skipReports>false</skipReports>
</configuration>

• including defines a comma separated list of patterns for the classes that should be included (default: all).

• excluding defines a comma separated list of patterns for the classes that should be excluded (default: none).

• ignoring defines a list of dependencies that should be ignored when checking cycle constraints on the analyzed classes (default none). This setting differs from excluding as the ignored dependency is not excluded from the dependency graph (i.e. it is present in the report). Each ignored dependency is represented by a dependency element containing from and to patterns, both are optional:

  • from defines the source of the dependency (default: all)
  • to defines the target of the dependency (default: all)

• slicings defines a list of slicings for the packages. Each slicing is represented by a slicing element containing name and patterns elements, both are required:

  • name defines the name of the slicing
  • patterns defines a comma separated list of patterns, in which each pattern is either an unnamed pattern (containing curly braces for determining the slice) or a named pattern of the form pattern=slice (in which slice is the name of the slice and pattern is a simple pattern)
  • constraints enables the configuration of additional constraints on the defined slices
    • allow defines a simple order constraint
    • allow-direct defines a strict order constraint
    • both allow and allow-direct may either contain a comma separated list of slice names, or they may contain only any-of and one-of elements (and no direct text content)
    • any-of contains comma separated slices names with an unspecified slice order
    • one-of contains comma separated slices names that must not depend on each other

• ignoreFailures whether to allow the build to continue if there are constraint violations (default: false). This parameter can also be specified by defining the property decycle.ignoreFailures

• skip whether to skip the execution of decycle (default: false). This parameter can also be specified by defining the property decycle.skip

• skipMain whether to skip the execution of decycle on the main classes (default: false). This parameter can also be specified by defining the property decycle.skipMain

• skipTest whether to skip the execution of decycle on the test classes (default: false). This parameter can also be specified by defining the property decycle.skipTest

• skipReports whether to skip the creation of the HTML reports (default: false). This parameter can also be specified by defining the property decycle.skipReports