Download all Gradle project dependecies

DownloadDependenciesTask.kt

import org.gradle.api.DefaultTask
import org.gradle.api.artifacts.Configuration
import org.gradle.api.attributes.Attribute
import org.gradle.api.model.ObjectFactory
import org.gradle.api.tasks.*
import org.gradle.kotlin.dsl.setProperty
import java.io.File
import javax.inject.Inject

/**
 * Syncs project all configurations artifacts files.
 *
 * By default downloads only "jar" or "aar", can be changed by providing another value
 * to [artifactTypes] property.
 *
 * For multi-module project can be applied using following code:
 * ```gradle
 * allprojects { subProject ->
 *    subProject.tasks.register("downloadDependencies", com.freeletics.gradle.DownloadDependenciesTask.class) {
 *        group = HelpTasksPlugin.HELP_GROUP
 *        description = "Syncs (downloads if required) all project dependencies"
 *    }
 * }
 * ```
 */
// Disabling caching for this task until `projectConfiguration` input will not fail
// with AmbiguousVariantSelectionException exception
//@CacheableTask
open class DownloadDependenciesTask @Inject constructor(
    objectFactory: ObjectFactory
) : DefaultTask() {
    private val artifactTypeAttribute = Attribute.of("artifactType", String::class.java)

//    @get:Input
    @get:Internal
    val artifactTypes = objectFactory.setProperty(String::class).apply {
        set(setOf("jar", "aar", "apk"))
    }

//    @get:Classpath
    @get:Internal
    internal val buildScriptConfiguration = project.buildscript.configurations
        .matching { it.isCanBeResolved }

//    @get:Classpath
    @get:Internal
    internal val projectConfiguration = project.configurations
        .matching { it.isCanBeResolved }

    @get:OutputFiles
    internal val artifactFiles: MutableList<File> = mutableListOf()

    @TaskAction
    fun syncDependencies() {
        buildScriptConfiguration
            .forEach { configuration ->
                configuration.incoming.resolutionResult.allDependencies
                resolveConfiguration(configuration, artifactTypes.get(), artifactTypeAttribute)
            }
        projectConfiguration
            .forEach { configuration ->
                configuration.incoming.resolutionResult.allDependencies
                resolveConfiguration(configuration, artifactTypes.get(), artifactTypeAttribute)
            }
    }

    private fun resolveConfiguration(
        configuration: Configuration,
        artifactTypes: Set<String>,
        artifactTypeAttribute: Attribute<String>
    ) {
        artifactTypes.forEach { type ->
            configuration
                .incoming
                .artifactView {
                    isLenient = true
                    attributes {
                        attribute(artifactTypeAttribute, type)
                    }
                }
                .artifacts
                .forEach {
                    logger.info("Syncing artifact: $it")
                    artifactFiles.add(it.file)
                }
        }
    }
}

sync-dependencies.gradle

tasks.register("downloadDependencies") {
    group = HelpTasksPlugin.HELP_GROUP
    description = "Syncs (downloads if required) all project dependencies"

    doLast {
        def artifactTypes = ['jar', 'aar']
        def artifactTypeAttribute = Attribute.of('artifactType', String)

        project.rootProject.allprojects.each { subProject ->
            subProject.buildscript.configurations.each { configuration ->
                resolveConfiguration(configuration, artifactTypes, artifactTypeAttribute)
            }
            subProject.configurations.each { configuration ->
                resolveConfiguration(configuration, artifactTypes, artifactTypeAttribute)
            }
        }
    }
}

private static void resolveConfiguration(
        configuration,
        artifactTypes,
        artifactTypeAttribute
) {
    if (configuration.isCanBeResolved()) {
        artifactTypes.each { type ->
            configuration.incoming.artifactView {
                lenient = true
                attributes {
                    it.attribute(artifactTypeAttribute, type)
                }
            }.artifacts.each {}
        }
    }
}