Q: How to reuse target sourceSet for another target? (MPP)

[4ntoine]

I need to reuse jvm sourceSet for android target.
In 1.3.11 it worked:

 fromPreset(presets.jvm, 'jvm')
 fromPreset(presets.android, 'jvm')

In 1.3.20 it stopped working:

The target 'jvm' already exists, but it was not created with the 'android' preset. To configure it, access it by name in kotlin.targets or use the preset function 'jvm' Open File

BTW i believe it should be by default: android target to use jvm sourceSet (and overrides) existing source if present.

I've tried to add jvm default source set to android target but no luck:

  jvm()
  android() {
     sourceSets.add(kotlin.targets.jvm.compilations.main.defaultSourceSet)
  }

Actual impl not found for expected class.

Bug/feature? How can i do it?

[Dominaezzz]

You could point their defaultSourceSets to the same directory using kotlin.srcDir().
Like this https://kotlinlang.org/docs/reference/building-mpp-with-gradle.html#configuring-source-sets

[4ntoine]

Well, it can be a solution probably. But it would make all android sources (actual) equal to jvm. I need to add jvm to android but not limit to it.

[Dominaezzz]

I had a similar problem in a project of mine. You could do one of two things.
Declare a common source set for Android and jvm and then have their specific source sets depend on the common one.

Have android and jvm share a source folder, then android can have another specific source folder and jvm can have another source folder.

[4ntoine]

@Dominaezzz That should work. The whole difficulty for me is still the same - how to add sourceset for platform target. Now it's just "add shared between jvm and android targets sourceset instead of just jvm's sourceset". Can you please share build.gradle part for this?

[Dominaezzz]

Sharing a source set.

jvm ()
android()

sourceSets {
    val commonJvmMain by creating {
        dependencies {
            implementation(kotlin("stdlib-common"))
        }
    }
    val jvmMain by getting {
        dependsOn(commonJvmMain)
    }
    val androidMain by getting {
        dependsOn(commonJvmMain)
    }
}

or

Sharing a source directory.

jvm ()
android()

sourceSets {
    val jvmMain by getting {
        kotlin.srcDir("src/commonJvmMain/kotlin")
        resources.srcDir("src/commonJvmMain/resources")
    }
    val androidMain by getting {
        kotlin.srcDir("src/commonJvmMain/kotlin")
        resources.srcDir("src/commonJvmMain/resources")
    }
}

Both of these should work but the first one might play nicer with the IDE.
(Haven't tested this exact config, I don't have my computer at the moment).

[4ntoine]

That worked (Groovy):

       commonJvmMain {
            dependencies {
                implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8'
            }
        }
        jvmMain {
            dependsOn commonJvmMain
        }
        androidMain {
            dependsOn commonJvmMain
        }

Thanks, @Dominaezzz !