Motivation

Commonly people want to run particular stages when they match a specific branch name(s). We would like to make this pattern accessible in the editor.

Declarative allows the use of when to condition the stage execution like:

stage('second') {
    agent label:'some-node'
    branch "master" 
    when {
        env.BRANCH == 'master'
    }
}

However, this isn't exactly what we would consider "friendly" for an editor accessible feature (though when will be supported via a text area) and the developer would have to learn the Script syntax to use it correctly.

Solution

We would like to formalise the pattern in a way that is more Editor and user friendly with the introduction of branch. Ideally we could tell from BO if the user has skipped via when or via branch.

Example - match single branch
This stage would only be executed if master was the name of the current branch.

stage('deploy to staging') {
    agent label:'some-node'
    when { branch "master" }
    steps {
        sh './deploy_pr.sh'
    }
}

Example - match branch name pattern
This stage would only be executed if the branch name started with feature/.

stage('deploy to staging') {
    agent label:'some-node'
    when { branch "feature/*" }
    steps {
        sh './deploy_pr.sh'
    }
}

Example - expression
You can use an expression to achieve the same thing by:

stage('deploy to staging') {
    agent label:'some-node'
    when {
	expression {
		return BRANCH == 'master';
        }
    }
    steps {
        sh './deploy_pr.sh'
    }
}