KTOR-8162: Generate version catalogs (#4875)

* Add ktor-version-catalog generation
* Move BOM publishing to ktorbuild.publish

Author: osipxd

build-logic/src/main/kotlin/ktorbuild.publish.gradle.kts

@@ -66,6 +66,18 @@ plugins.withId("ktorbuild.kmp") {
     configureJavadocArtifact()
 }
 
+pluginManager.withPlugin("java-platform") {
+    publishing.publications.register<MavenPublication>("maven") {
+        from(components["javaPlatform"])
+    }
+}
+
+pluginManager.withPlugin("version-catalog") {
+    publishing.publications.register<MavenPublication>("maven") {
+        from(components["versionCatalog"])
+    }
+}
+
 private fun Project.configureSigning() {
     extra["signing.gnupg.keyName"] = (System.getenv("SIGN_KEY_ID") ?: return)
     extra["signing.gnupg.passphrase"] = (System.getenv("SIGN_KEY_PASSPHRASE") ?: return)

gradle/artifacts/publishJvmAndCommonPublications.txt

@@ -623,6 +623,7 @@ io.ktor:ktor-utils-jvm/sources.jar
 io.ktor:ktor-utils/.jar
 io.ktor:ktor-utils/kotlin-tooling-metadata.json
 io.ktor:ktor-utils/sources.jar
+io.ktor:ktor-version-catalog/.toml
 io.ktor:ktor-websocket-serialization-jvm/.jar
 io.ktor:ktor-websocket-serialization-jvm/javadoc.jar
 io.ktor:ktor-websocket-serialization-jvm/sources.jar

ktor-bom/build.gradle.kts

@@ -7,18 +7,9 @@ import ktorbuild.*
 plugins {
     id("ktorbuild.base")
     id("java-platform")
-    id("maven-publish")
+    id("ktorbuild.publish")
 }
 
-publishing.publications {
-    create<MavenPublication>("maven") {
-        from(components.findByName("javaPlatform"))
-    }
-}
-
-// Should be applied after publications were configured
-apply(plugin = "ktorbuild.publish")
-
 val allPublications = projectsWithTag(ProjectTag.Library)
     .flatMapValue { libraryProject ->
         libraryProject.publishing.publications

ktor-version-catalog/build.gradle.kts

@@ -0,0 +1,106 @@
+/*
+ * Copyright 2014-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+import ktorbuild.*
+
+plugins {
+    id("ktorbuild.base")
+    id("version-catalog")
+    id("ktorbuild.publish")
+}
+
+val publishedProjectsProvider = projectsWithTag(ProjectTag.Published, Project::getName)
+
+// A hack to prevent all projects evaluation if version catalog generation wasn't requested
+// Issue: https://github.com/gradle/gradle/issues/33568
+gradle.taskGraph.whenReady {
+    if (allTasks.any { it.name == VersionCatalogPlugin.GENERATE_CATALOG_FILE_TASKNAME }) {
+        catalog.versionCatalog {
+            configureVersionCatalog(
+                group = project.group.toString(),
+                version = project.version.toString(),
+                publishedProjects = publishedProjectsProvider.get().toSet(),
+            )
+        }
+    }
+}
+
+fun VersionCatalogBuilder.configureVersionCatalog(
+    group: String,
+    version: String,
+    publishedProjects: Set<String>,
+) {
+    // Versions
+    val versionAlias = version("ktor", version)
+
+    // Libraries
+    for (projectName in publishedProjects - excludedProjects) {
+        if (projectName == "ktor-version-catalog") continue
+        library(
+            /* alias = */ libraryAlias(projectName, publishedProjects + hierarchyRoots),
+            /* group = */ group,
+            /* artifact = */ projectName,
+        ).versionRef(versionAlias)
+    }
+    library("gradlePlugin", "io.ktor.plugin", "plugin").versionRef(versionAlias)
+
+    // Plugins
+    plugin("ktor", "io.ktor.plugin").versionRef(versionAlias)
+}
+
+// Projects that are published but should be excluded from the version catalog.
+// This means we don't want our users to use these dependencies.
+val excludedProjects = setOf(
+    "ktor-client",
+    "ktor-server",
+    "ktor-server-host-common",
+)
+
+val hierarchyRoots = setOf(
+    "ktor",
+    "ktor-client",
+    "ktor-server",
+)
+
+// Handle special cases when automatic mapping doesn't work well
+val manualOverrides = mapOf(
+    // We want to preserve the hierarchy in case we add more config formats
+    "ktor-server-config-yaml" to "server-config-yaml",
+    // Fix a typo in the project name
+    "ktor-websocket-serialization" to "websockets-serialization",
+    // Prefer '*-jakarta' artifacts over the deprecated ones
+    "ktor-client-jetty-jakarta" to "client-jetty",
+    "ktor-client-jetty" to "client-jetty-legacy",
+    "ktor-server-jetty-jakarta" to "server-jetty",
+    "ktor-server-jetty" to "server-jetty-legacy",
+    "ktor-server-servlet-jakarta" to "server-servlet",
+    "ktor-server-servlet" to "server-servlet-legacy",
+    "ktor-server-tomcat-jakarta" to "server-tomcat",
+    "ktor-server-tomcat" to "server-tomcat-legacy",
+)
+
+/**
+ * Generates a library alias for a given [projectName] to use in the version catalog.
+ *
+ * This function converts hierarchical project names into appropriately structured aliases.
+ * For example, `ktor-client-content-negotiation` becomes `client-contentNegotiation`.
+ */
+fun libraryAlias(projectName: String, possiblePrefixes: Set<String>): String {
+    if (projectName in manualOverrides) return manualOverrides.getValue(projectName)
+
+    var prefix = projectName.substringBeforeLast("-")
+    var suffix = projectName.substringAfterLast("-")
+
+    while (prefix !in possiblePrefixes) {
+        val lastWord = prefix.substringAfterLast("-")
+        prefix = prefix.substringBeforeLast("-")
+        suffix = lastWord + suffix.replaceFirstChar { it.uppercase() }
+    }
+
+    return if (prefix != "ktor") {
+        "${libraryAlias(prefix, possiblePrefixes)}-$suffix"
+    } else {
+        suffix
+    }
+}

settings.gradle.kts

@@ -186,6 +186,7 @@ projects {
     +"ktor-test-dispatcher"
     +"ktor-java-modules-test"
     +"ktor-dokka"
+    +"ktor-version-catalog"
 }
 
 // region Project hierarchy DSL