github-changelist-plugin

This Jenkins plugin gets updated files from GitHub.

This is useful plugin for a following case.

If you have too many and too slow test cases and you want to restrict test cases affected by updated files, you can get the updated file's paths and extract part of path you need. Then you can restrict to execute test cases by using updated files and test-tools like Maven.

Restrictions

• Support using in Pipeline, not support free-style job
• Now, support only using with Pipeline Multibranch Plugin.
• Support only GitHub, GitHub Enterprise

Required Jenkins Plugins

• Credentials Plugin (https://wiki.jenkins-ci.org/display/JENKINS/Credentials+Plugin)
• GitHub API Plugin (https://wiki.jenkins-ci.org/display/JENKINS/GitHub+API+Plugin)
• GitHub Branch Source Plugin (https://wiki.jenkins-ci.org/display/JENKINS/GitHub+Branch+Source+Plugin)
• Pipeline Multibranch Plugin (https://wiki.jenkins-ci.org/display/JENKINS/Pipeline+Multibranch+Plugin)
• Pipeline Step API Plugin (https://wiki.jenkins-ci.org/display/JENKINS/Pipeline+Step+API+Plugin)

How to use

#!groovy
pipeline {
  agent any
  stages {
    stage('get changelist') {
      steps {
        script {
           // if updated files are 
           // 'src/main/java/aha/oretama/jp/GitHubChangelistStep.java', 
           // 'src/main/java/aha/oretama/jp/RegexUtils.java',
           // 'src/test/java/aha/oretama/jp/RegexUtilsTest.java'
          
           def changes = changelist regex: '([^/]*$)', testTargetRegex: '$1' 
           echo changes.join(',')
           // display 'GitHubChangelistStep.java,RegexUtils.java,RegexUtilsTest.java'
          
           def defaultChanges =  changelist() // default regex: '([^/]*?)(Test)?(\..*)?$', testTargetRegex = '**/$1Test*'
           echo defaultChanges.join(',')
           // display '**/GitHubChangelistStepTest*,**/RegexUtilsTest*'
        }
      }
    }
  }
}

Features

• regex must have at least one group
• testTargetRegex is made from group index and optional added word,
  such as $1, $1Test$3
• testTargetRegex is replaced by groups matched in regex
• default regex is ([^/]*?)(Test)?(\..*)?$
• default testTargetRegex is **/$1Test*

Best Practice

In restricting test cases affected by updated files, you can implement by using this plugin and testing tools like Maven. Here is the example of using Maven.

You add inclusions.txt written as follows.

**/Test*.java
**/*Test.java
**/*Tests.java
**/*TestCase.java

These are default values in includes parameter in Maven Surefire Plugin.

Next, you add includes, includesFile in pom.xml.

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.19.1</version>
        <configuration>
            <argLine>-Dfile.encoding=UTF-8</argLine>
            <includes>
                <include>Nothing</include>
            </includes>
            <includesFile>${project.basedir}/inclusions.txt</includesFile>
        </configuration>
    </plugin>

These you've done are to be able to change executing test only by inclusions.txt.

Therefore, you write pipeline as follows, you can restrict test cases affected by updated files.

pipeline {
  agent any
  stages {
    stage('Execute test case affected by changed files') {
      steps {
        script {
          def changes = changelist()
          echo changes.join(',')
          if(!changes) {
            // No changes, do not run test.
            return
          }
    
          // Execute only test cases affected by changed files
          writeFile file: 'inclusions.txt', text: changes.join('\n')
          sh 'mvn clean test'
    
          // Note that no surefire-repot if no test run.
          def exists = fileExists 'target/surefire-reports'
          if(exists) {
            junit 'target/surefire-reports/**/*.xml'
          }
        }
      }
    }
  }
}