Code Style: astyle

If the plugin git-code-format-maven-plugin is in the <build><plugins> section of your pom.xml, you can do code format/style checking automatically via mvn, and then automate that in your CI/CD pipeline.

Documentation for this plugin can be found here:

• https://github.com/Cosium/git-code-format-maven-plugin

An example of what you need in your pom.xml to enable this appears below.

Checking and fixing the formatting

The formatting will be checked anytime you run mvn verify (unless you specify -Dgcf.skip as in mvn verify -Dgcf.skip) However, that will also run all of the other checks that are part of the mvn verify cycle.

To check the formatting and nothing else, use:

mvn git-code-format:validate-code-format

To fix the formatting, use:

mvn git-code-format:format-code

Afterwards, do a git status to see which files were changed, or git diff to see the changes.

Example plugin code

Here is an example of what goes in your pom.xml, in the section <build><plugins> ... </plugins></build>:

              <plugin>
                <groupId>com.cosium.code</groupId>
                <artifactId>git-code-format-maven-plugin</artifactId>
                <version>5.1</version>
                <executions>
                    <execution>
                        <id>validate-code-format</id>
                        <goals>
                            <goal>validate-code-format</goal>
                        </goals>
                    </execution>
                </executions>
                <dependencies>
                    <!-- Enable https://github.com/google/google-java-format -->
                    <dependency>
                        <groupId>com.cosium.code</groupId>
                        <artifactId>google-java-format</artifactId>
                        <version>5.1</version>
                    </dependency>
                </dependencies>
            </plugin>

Adjusting workflows

After you add this to your pom.xml, you may experience the unintended consequence that other workflows that use the verify phase of Maven’s lifecycle–such as the jacoco:check step which checks whether code coverage percentages are within the tolerances specified in the pom.xml–may start to fail if the code is improperly formatted. This may be undesirable; it’s more informative when CI/CD workflows that are checking independent aspects of the code report those independently.

To prevent a mvn verify step from checking code formatting, just add -Dgcf.skip as in this example:

Instead of using this in a workflow for jacoco:

mvn test jacoco:report verify

Use this:

mvn test -Dgcf.skip jacoco:report verify