I don't like this syntax formatting.

When I see this :

stage ('Incremental Build') {
        when {
            not { stage 'Full Build' }
        }
    }

I read it as when this Stage is not "Full Build". My first reaction is that is always true.

If we want to say it is dependent in someway then we need to make that relationship explicit. When stage "Full Build" is not what? Not skipped, not run, not stable? That isn't clear.

Right now the use case described is easily done as shown. To me that is much more clear than the alternative. We can explore having some stage conditions but they need to be clear.

Maybe something like:

stage ('Incremental Build') {
        when {
             stage 'Full Build'  == SKIPPED
        }
    }

Or

stage ('Incremental Build') {
        when {
             stage 'Full Build'  == SUCCESS
        }
    }

Or

stage ('Incremental Build') {
        when {
             stage 'Full Build'  != UNSTABLE
        }
    }

hrmpw
I'm open to discussion of how it should look, but I think we need some form of this.

"Right now the use case described is easily done as shown."
Yes, like I said, for simple expressions things are fine, but for complex expressions this would get unwieldy very fast.

stages {
    stage ('Full Build') {
        when {
            expression {
                GIT_BRANCH = 'origin/' + sh(returnStdout: true, script: 'git rev-parse --abbrev-ref HEAD').trim()
                return GIT_BRANCH == 'origin/master' || params.FORCE_FULL_BUILD
            }
        }
    }

    stage ('Incremental Build') {
        when {
            expression {
                GIT_BRANCH = 'origin/' + sh(returnStdout: true, script: 'git rev-parse --abbrev-ref HEAD').trim()
                return !(GIT_BRANCH == 'origin/master' || params.FORCE_FULL_BUILD)
            }
        }
    }
}

Then repeat that condition over and over for other stages. Mediocre.

I see your point about the specific `stage {}` condition syntax I described being not great, but I also don't want to use general comparison operators if we can avoid them here. Also, stages run in serial and failure in a previous stage would generally stop the pipeline right?

Maybe this:

stages {
    stage ('Full Build') {
        when {
            expression { return params.FORCE_FULL_BUILD }
        }
    }

    stage ('Incremental Build') {
        when {
            stages('Full Build').skipped
        }
    }

    stage ('Full Tests') {
        when {
            stages('Full Build').executed
        }
    }

    stage ('Incremental Tests') {
        when {
            stages('Incremental Build').executed
        }
    }
}

Or we could follow your status example:

stages {
    stage ('Full Build') {
        when {
            expression { return params.FORCE_FULL_BUILD }
        }
    }

    stage ('Incremental Build') {
        when {
            stages('Full Build').skipped
        }
    }

    stage ('Full Tests') {
        when {
            stages('Full Build').succeeded 
        }
    }

    stage ('Incremental Tests') {
        when {
            stages('Incremental Build').succeeded
        }
    }
}

I agree with this wholeheartedly. Has this gotten any traction lately? 

I'm implementing this in a new plugin - https://github.com/abayer/declarative-pipeline-when-conditions-plugin.

Oh, and the conditional syntax is stageHasRun "some-stage" - just stage caused things to blow up at parse-time due to stage being overloaded twice already. =) I went with the original syntax - it checks if the stage has run or is running and hasn't been skipped (due to conditional or earlier failure or whatever). Since stages don't yet have their own statuses in a real way, we don't have any way to compare against stage status.

Has there been any progress on this? I find myself in need of a solution to know if an earlier stage has been built.

I found myself needing something similar - a set of mutually exclusive stages of which only one should execute. I would actually prefer something like this:

stage ("Do It") {
    switch {
        stage("Stage A") {
            when { expression { return conditionA } }
            steps { ... }
        }
        stage("Stage B") {
             when { expression { return conditionB } }
             steps { ... }
        }
        stage("Stage C") {
            steps { ... }
        }
    }
}

This means "If condition A, do Stage A. Else if condition B, do Stage B. Else, do Stage C." switch would be at the same level as stages, parallel, and matrix today. This allows Blue Ocean to clearly display the mutually exclusive stages (probably in a vertical arrangement, like it does for parallel).

rittneje
Wow. Yeah, I like that idea. It is a separate idea from this, though I see the relation. Please file an issue for it.

bnacey
No there hasn't been more progress on this issue. It stalled out. Restarting it would require some effort.