when:
        collection.from = ["a", "b"]
        then:
        collection.from as List == [["a", "b"]]
    }

    def "can mutate the from collection"() {
        collection.from("src1", "src2")
        def from = collection.from

        when:
        from.clear()

        then:
        from.empty
        collection.from.empty

        when:
        def add1 = from.add('a')

        when:
        container.whenObjectAdded(action)

        then:
        // Does not fire for existing elements
        0 * action._

        when:
        addToContainer(a)

        then:
        1 * action.execute(a)
        0 * action._

        when:
        addToContainer(a)

        then:
        0 * action._

        when:

        property.set(someValue())

        when:
        property.finalizeValueOnRead()

        then:
        0 * _

        when:
        def value = property.orNull

        then:
        value == someValue()

        and:
        1 * host.beforeRead(null) >> null
    }

    def "can disallow changes when host is not ready when unsafe read disallowed"() {
        given:

    def "can change value to empty map"() {
        when:
        property.set([a: 'b'])
        property.empty()
        then:
        assertValueIs([:])
    }

    def "can set value using empty map"() {
        when:
        property.set([:])
        then:
        assertValueIs([:])
    }

    def "returns immutable copy of value"() {
        when:
        property.set(['k': 'v'])
        then:

    }

    def "throws NullPointerException when provider returns list with null to property"() {
        given:
        property.addAll(Providers.of([null]))

        when:
        property.get()

        then:
        def ex = thrown(NullPointerException)
    }

    def "throws NullPointerException when adding a null value to the property"() {
        when:
        property.add(null)

        then:

        when:
        configuration.extendsFrom(conf("other"))
        then:
        thrown(InvalidUserDataException)

        when:
        configuration.dependencies.add(Mock(Dependency))
        then:
        thrown(InvalidUserDataException)

        when:
        configuration.dependencies.remove(Mock(Dependency))
        then:
        thrown(InvalidUserDataException)

        when:

               into 'dest'
            }
        '''

        when:
        run 'copy'
        then:
        executedAndNotSkipped(":copy")

        when:
        file("files/sub/empty").createDir()
        run 'copy'
        then:
        executedAndNotSkipped(":copy")

        when:
        run 'copy'
        then:
        skipped(":copy")
    }

    }

    def "finalizer dependency runs even when finalizer does not run when dependency is also an entry task"() {
        given:
        Task finalizerDepDep = task("finalizerDepDep", type: Async)
        Task finalizerDep = task("finalizerDep", type: Async, dependsOn: [finalizerDepDep])
        Task finalizer = task("finalizer", type: Async, dependsOn: [finalizerDep])

                }
            }
        }

        when:
        run 'checkDeps'

        then:
        outputContains("Providing metadata for group:projectB:2.2")
        outputContains("Providing metadata for group:projectB:1.1")

        when:
        // stop the daemon to make sure that when we run the build again
        // it's fetched from the persistent cache

        setupBuildWithArtifactTransformOfProjectDependencies()

        when:
        configurationCacheRun(":resolve")

        then:
        assertTransformed("a.jar", "b.jar")
        outputContains("result = [a.jar.green, b.jar.green]")

        when:
        configurationCacheRun(":resolve")

        then: // everything is up-to-date