Gradle inferred task dependency

build.gradle.kts

open class TestingTask : DefaultTask() {

    @InputFiles
    var inputDirs = mutableListOf<Task>()

    @OutputDirectory
    var out: File? = null

    @TaskAction
    fun createOutputDir() {
        println("Executed task named ‘$name' \uD83C\uDF89")
    }

}

tasks.register("first", TestingTask::class.java) {
    inputDirs.add(task("emptyTask"))
    out = File("$buildDir/firstOutput")
}

tasks.register("second", TestingTask::class.java) {
    inputDirs.add(tasks.getByName("first"))
    out = File("$buildDir/secondOutput")
}

output.txt

$ ./gradlew second 

> Task :first
Executed task named 'first' 🎉

> Task :second
Executed task named 'second' 🎉

BUILD SUCCESSFUL in 0s
2 actionable tasks: 2 executed

$ ./gradlew second 

BUILD SUCCESSFUL in 0s
2 actionable tasks: 2 up-to-date