Differential Check for Maven

A framework and maven plugin for applying differential checks or rules on projects using git. A differential check determines violations present in the diff between a given source and target branch. Only edits are checked for violations, i.e. lines that were added or modified but not deleted.

This can be useful to enforce code quality tools as part of git pull-request workflow. This tool encourages developers to improve new and existing design, one pull-request/branch at a time. Combined with the git-ratchet tool, which takes more of a global approach for quality improvement, existing codebase can be improved iteratively.

Usage

DfCheck maven plugin can be added to the project's pom.xml as follows:

            <build>
                <plugins>
                    ...
                    <plugin>
                        <groupId>com.atlassian.dfcheck</groupId>
                        <artifactId>dfcheck-maven-plugin</artifactId>
                        <version>1.0</version>
                        <executions>
                            <execution>
                                <id>diff-check</id>
                                <goals>
                                    <goal>dfcheck</goal>
                                </goals>
                            </execution>
                        </executions>
                    </plugin>
                    ...
                </plugins>
            </build>

By default DfCheck binds itself to the VERIFY Lifecycle Phase of maven. It can be customised via the <execution> element.

Configuration

The plugin can be configured using the <configuration> element inside the plugin declaration. These can also be passed as command line parameters e.g. -Ddfcheck.skip=true

• failOnViolation - Fail the build if there are violations, true|false Default: true

• readUncommitted - Read uncommitted changes (by default), set to false if only committed changes must be tracked true|false, Default: true

• mode - How to calculate the effective diff, can be: add|mod|edit, Default: edit

  • add mode: only lines that were added will be checked.
  • mod mode: only lines that were modified will be checked.
  • edit mode (default): combination of add and mod, both additions and modifications are included

• consoleOutput - whether violations should be printed in console, true|false Default: true

• skip - Skip execution of the plugin. true|false, Default: false

Checkstyle

• checkstyleEnabled - whether checkstyle can raise violations true|false Default: true
• checkstyleSeverity - the severity that is considered a violation warn|error Default: error
• checkstyleReport - the directory where checkstyle report is generated. Default: ${project.build.directory}/checkstyle-result.xml

PMD

• pmdEnabled - whether PMD can raise violations true|false Default: false
• pmdSeverity - the severity that is considered a violation warn|error Default: error
• pmdReport - the directory where PMD report is generated.

FindBugs

• findBugsEnabled - whether findbugs can raise violations true|false Default: false
• findBugsSeverity - the severity that is considered a violation warn|error Default: error
• findBugsReport - the directory where findbugs report is generated.

Running Differential Check

Checks for violation using the check goal:

mvn dfcheck:dfcheck

The target branch is by default the master branch, but can be overridden as follows

mvn dfcheck:dfcheck -Ddfcheck.target=integration-branch

Violations are printed in the following format:

FileA:
    [LineNumber1] ViolationDescription1 [PluginName:ViolationSource1]
    [LineNumber2] ViolationDescription2 [PluginName:ViolationSource2]
    
FileB:
    [LineNumber1] ViolationDescription1 [PluginName:ViolationSource1]
...

Show Effective Diff

In order to see the effective diff that will be checked for violations, use the diff goal

mvn dfcheck:diff

The format of the output is:

FileA:[[lineNumber-range1], [lineNumber-range2] ..]
FileB:[[lineNumber-range1], [lineNumber-range2] ..]
...

License

Copyright 2015 Raz Shahriar

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.