How to merge before build in a multi-branch pipeline?

Question

For simple pipeline jobs I have the "merge before build" under Additional Behaviours. But how do I do that in a multi-branch pipeline? Can't find that option.

Thanks in advance.

Answer 1

I will just post here what I did through code:

def mergeBeforeBuild() {

  // Pull the source and test a merge
  try {
    def sourceScmCheck = checkout changelog: true, poll: true, scm: [
      $class: 'GitSCM',
      branches: [[name: "origin/$sourceBranch" ]],
      doGenerateSubmoduleConfigurations: false,
      extensions: [[
        $class: 'PreBuildMerge',
        options: [
          fastForwardMode: 'FF',
          mergeRemote: 'origin',
          mergeStrategy: 'default',
          mergeTarget: "${env.target_branch}"]],
        [$class: 'UserIdentity',
          email: '[email protected]',
          name: 'jenkins'
      ]],
      submoduleCfg: [],
      userRemoteConfigs: [[
        credentialsId: 'githubCredentials',
        name: 'origin',
        url: "$repoUrl"
      ]]
    ]
  } catch (error) {
    currentBuild.result = 'FAILURE'
    echo "ERROR: ${error}"
    sh 'false'
  }
}