Improve copying base-frontend files between subprojects (#2970)

build-logic/src/main/kotlin/org/jetbrains/conventions/dokka-html-frontend-files.gradle.kts

@@ -0,0 +1,31 @@
+package org.jetbrains.conventions
+
+import org.gradle.api.attributes.Usage.USAGE_ATTRIBUTE
+
+/**
+ * Utility for sharing the Dokka HTML frontend files between subprojects in a safe, cacheable way.
+ */
+
+plugins {
+    id("org.jetbrains.conventions.base")
+}
+
+/** Apply a distinct attribute to the incoming/outgoing configuration */
+fun AttributeContainer.dokkaHtmlFrontendFilesAttribute() =
+    attribute(USAGE_ATTRIBUTE, objects.named("org.jetbrains.dokka.html-frontend-files"))
+
+// incoming configuration
+val dokkaHtmlFrontendFiles by configurations.registering {
+    description = "Retrieve Dokka HTML frontend files from other subprojects"
+    isCanBeConsumed = false
+    isCanBeResolved = true
+    attributes { dokkaHtmlFrontendFilesAttribute() }
+}
+
+// outgoing configuration
+val dokkaHtmlFrontendFilesElements by configurations.registering {
+    description = "Provide Dokka HTML frontend files to other subprojects"
+    isCanBeConsumed = true
+    isCanBeResolved = false
+    attributes { dokkaHtmlFrontendFilesAttribute() }
+}

build.gradle.kts

@@ -39,7 +39,6 @@ apiValidation {
     // note that subprojects are ignored by their name, not their path https://github.com/Kotlin/binary-compatibility-validator/issues/16
     ignoredProjects += setOf(
         // NAME                    PATH
-        "search-component",    // :plugins:search-component
         "frontend",            // :plugins:base:frontend
 
         "kotlin-analysis",     // :kotlin-analysis

gradle/libs.versions.toml

@@ -41,6 +41,7 @@ node = "16.13.0"
 gradlePlugin-shadow = "7.1.2"
 gradlePlugin-nexusPublish = "1.1.0"
 gradlePlugin-gradlePluginPublish = "0.20.0"
+gradlePlugin-gradleNode = "3.5.1"
 
 ## Test
 junit = "5.9.2"
@@ -109,3 +110,4 @@ kotlinx-binaryCompatibilityValidator = { id = "org.jetbrains.kotlinx.binary-comp
 shadow = { id = "com.github.johnrengelman.shadow", version.ref = "gradlePlugin-shadow" }
 gradlePublish = { id = "com.gradle.plugin-publish", version.ref = "gradlePlugin-gradlePluginPublish" }
 nexusPublish = { id = "io.github.gradle-nexus.publish-plugin", version.ref = "gradlePlugin-nexusPublish" }
+gradleNode = { id = "com.github.node-gradle.node", version.ref = "gradlePlugin-gradleNode" }

plugins/base/build.gradle.kts

@@ -3,6 +3,7 @@ import org.jetbrains.registerDokkaArtifactPublication
 plugins {
     id("org.jetbrains.conventions.kotlin-jvm")
     id("org.jetbrains.conventions.maven-publish")
+    id("org.jetbrains.conventions.dokka-html-frontend-files")
 }
 
 dependencies {
@@ -33,45 +34,40 @@ dependencies {
     testImplementation(projects.core.testApi)
     testImplementation(platform(libs.junit.bom))
     testImplementation(libs.junit.jupiter)
+
+    dokkaHtmlFrontendFiles(projects.plugins.base.frontend) {
+        because("fetch frontend files from subproject :plugins:base:frontend")
+    }
 }
 
-val projectDistDir = project(":plugins:base:frontend").file("dist")
-val generateFrontendFiles = tasks.getByPath(":plugins:base:frontend:generateFrontendFiles")
+// access the frontend files via the dependency on :plugins:base:frontend
+val dokkaHtmlFrontendFiles: Provider<FileCollection> =
+    configurations.dokkaHtmlFrontendFiles.map { frontendFiles ->
+        frontendFiles.incoming.artifacts.artifactFiles
+    }
+
+val preparedokkaHtmlFrontendFiles by tasks.registering(Sync::class) {
+    description = "copy Dokka Base frontend files into the resources directory"
 
-val copyJsFiles by tasks.registering(Copy::class) {
-    from(projectDistDir) {
+    from(dokkaHtmlFrontendFiles) {
         include("*.js")
+        into("dokka/scripts")
     }
-    dependsOn(generateFrontendFiles)
-    destinationDir =
-        File(sourceSets.main.get().resources.sourceDirectories.singleFile, "dokka/scripts")
-}
 
-val copyCssFiles by tasks.registering(Copy::class) {
-    from(projectDistDir) {
+    from(dokkaHtmlFrontendFiles) {
         include("*.css")
+        into("dokka/styles")
     }
-    dependsOn(generateFrontendFiles)
-    destinationDir =
-        File(sourceSets.main.get().resources.sourceDirectories.singleFile, "dokka/styles")
-}
 
-val copyFrontend by tasks.registering {
-    dependsOn(copyJsFiles, copyCssFiles)
+    into(layout.buildDirectory.dir("generated/src/main/resources"))
 }
 
-tasks {
-    processResources {
-        dependsOn(copyFrontend)
-    }
-
-    sourcesJar {
-        dependsOn(processResources)
-    }
+sourceSets.main {
+    resources.srcDir(preparedokkaHtmlFrontendFiles.map { it.destinationDir })
+}
 
-    test {
-        maxHeapSize = "4G"
-    }
+tasks.test {
+    maxHeapSize = "4G"
 }
 
 registerDokkaArtifactPublication("dokkaBase") {

plugins/base/frontend/build.gradle.kts

@@ -1,6 +1,10 @@
+import com.github.gradle.node.npm.task.NpmTask
+import org.jetbrains.kotlin.util.parseSpaceSeparatedArgs
+
+@Suppress("DSL_SCOPE_VIOLATION") // fixed in Gradle 8.1 https://github.com/gradle/gradle/pull/23639
 plugins {
-    base
-    id("com.github.node-gradle.node") version "3.2.1"
+    id("org.jetbrains.conventions.dokka-html-frontend-files")
+    alias(libs.plugins.gradleNode)
 }
 
 node {
@@ -11,19 +15,34 @@ node {
     distBaseUrl.set(null as String?) // Strange cast to avoid overload ambiguity
 }
 
-val npmRunBuild = tasks.getByName("npm_run_build") {
-    inputs.dir(file("src/main"))
-    inputs.files(file("package.json"), file("webpack.config.js"))
-    outputs.dir(file("dist/"))
+val distributionDirectory = layout.projectDirectory.dir("dist")
+
+val npmRunBuild by tasks.registering(NpmTask::class) {
+    dependsOn(tasks.npmInstall)
+
+    npmCommand.set(parseSpaceSeparatedArgs("run build"))
+
+    inputs.dir("src/main")
+    inputs.files(
+        "package.json",
+        "webpack.config.js",
+    )
+
+    outputs.dir(distributionDirectory)
     outputs.cacheIf { true }
 }
 
-task("generateFrontendFiles") {
-    dependsOn(npmRunBuild)
+configurations.dokkaHtmlFrontendFilesElements.configure {
+    outgoing {
+        artifact(distributionDirectory) {
+            builtBy(npmRunBuild)
+        }
+    }
 }
 
-tasks {
-    clean {
-        delete(file("node_modules"), file("dist"))
-    }
+tasks.clean {
+    delete(
+        file("node_modules"),
+        file("dist"),
+    )
 }

settings.gradle.kts

@@ -68,7 +68,6 @@ include(
 
     ":plugins:base",
     ":plugins:base:frontend",
-    ":plugins:base:search-component",
     ":plugins:base:base-test-utils",
     ":plugins:all-modules-page",
     ":plugins:templating",