[Core feature request] Add support to Workflow Dispatch Inputs

[LeoColman]

Discussed in Kotlin's Slack: https://app.slack.com/client/T09229ZC6/C02UUATR7RC/thread/C02UUATR7RC-1682902161.628869

What feature do you need?
Workflows Dispatch Inputs:
https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#onworkflow_dispatchinputs

Do you have an example usage?

https://github.com/kotest/kotest/blob/80bc809be1e0452dc1f3ee2e67aec2f6c7f6c251/.github/workflows/release_base.yml#L15

env:
   RELEASE_VERSION: ${{ inputs.version }}
   OSSRH_USERNAME: ${{ secrets.OSSRH_USERNAME }}
   OSSRH_PASSWORD: ${{ secrets.OSSRH_PASSWORD }}
   ORG_GRADLE_PROJECT_signingKey: ${{ secrets.SIGNING_KEY }}
   ORG_GRADLE_PROJECT_signingPassword: ${{ secrets.SIGNING_PASSWORD }}
   GRADLE_OPTS: -Dorg.gradle.configureondemand=true -Dorg.gradle.parallel=false -Dkotlin.incremental=false -Dorg.gradle.jvmargs="-Xmx3g -XX:MaxMetaspaceSize=756m -XX:MaxPermSize=2048m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8"

Is there a workaround for not having this feature? If yes, please describe it.

Yes. One can use WorkflowDispatch normally, and use expr { github["event.inputs.XXXX"]!! } to get the value when they need it.

workflow(
  name = "Publish",
  on = listOf(
    WorkflowDispatch(
      mapOf("RELEASE_VERSION" to Input("The release version", true, String))
    )
  ),
  sourceFile = __FILE__.toPath(),
  env = linkedMapOf(
    "OSSRH_USERNAME" to expr { OSSRH_USERNAME },
    "OSSRH_PASSWORD" to expr { OSSRH_PASSWORD },
    "ORG_GRADLE_PROJECT_signingKey" to expr { ORG_GRADLE_PROJECT_signingKey },
    "ORG_GRADLE_PROJECT_signingPassword" to expr { ORG_GRADLE_PROJECT_signingPassword },
    "RELEASE_VERSION" to expr { github["event.inputs.version"]!! }
  )
)

[krzema12]

As you've already noticed, some support for it is already in place (I forgot about it when asking you to create this request, sorry!):

github-workflows-kt/library/src/main/kotlin/io/github/typesafegithub/workflows/domain/triggers/WorkflowDispatch.kt

Lines 9 to 12 in 9eee511

	public data class WorkflowDispatch(
	val inputs: Map<String, Input> = emptyMap(),
	override val _customArguments: Map<String, @Contextual Any> = mapOf(),
	) : Trigger() {

From what I understand, you're missing a type-safe way of referring to the input values, right? On GitHub, the inputs are available within inputs context, and the library already supports several other contexts, see here. It should be enough to extend the library to support something like:

workflow(
  name = "Publish",
  on = listOf(
    WorkflowDispatch() // After the change, the inputs wouldn't be defined here...
  ),
  sourceFile = __FILE__.toPath(),
) {
    // ...but here instead. It's in line with what's already possible with env vars and secrets.
    val RELEASE_VERSION by Contexts.input(required = true, type = String)

    // ...
    // inside a job that actually uses the secret:
    run(
        name = "Release",
        env = linkedMapOf(
            VERSION to expr { RELEASE_VERSION },
        ),
        command = "./gradlew release",
    )
}

WDYT?

[krzema12]

@jmfayard do you recall why we originally haven't implemented it this way?

[jmfayard]

@krzema12 we probably implemented WorkflowDispatch before I implemented the typesafe expressions,
meaning we didn't design typesafe inputs at all

[LeoColman]

Yes, I think the syntax you presented seems what I expect @krzema12 . Interesting to know it predates the typesafety

[Vampire]

Type-safe access to the inputs would be nice.
One thing to consider, inputs can come from different sources, for example from WorkflowDispatch but also from WorkflowCall.
So with the suggested design it probably needs Contexts.workflowDispatchInput and Contexts.workflowCallInput.
Having one that injects to both might not be appropriate as both could have a different set of inputs or differences in required or default.
But the access to them would be identical in the resulting YAML as there the inputs share the same namespace.