Gradle / Kotlin + move common parts to project-plugin (apache#53)

Migrate Gradle/Groovy to Gradle/Kotlin-script.

Gradle/Kotlin is a bit slower to compile, but has proper type-safety and really good support in at least IntelliJ, and actually makes debugging build scripts possible. Gradle/Groovy is not really type safe and often yields quite surprising behavior.

Also moves the common project configuration to the project plugin `polaris-server` and the "boring" parts of `/build.gradle.kts` to the project plugin `polaris-root`.

Author: snazy

.gitignore

@@ -45,6 +45,7 @@ gradle/wrapper/gradle-wrapper-*.sha256
 
 # Gradle
 /.gradle
+/build-logic/.gradle
 **/build/
 !src/**/build/
 

extension/persistence/eclipselink/build.gradle renamed to build-logic/build.gradle.kts

@@ -14,22 +14,11 @@
  * limitations under the License.
  */
 
-dependencies {
-    implementation(project(":polaris-core"))
-    runtimeOnly(project(":polaris-service"))
-    implementation(libs.eclipselink)
-    implementation(platform(libs.dropwizard.bom))
-    implementation("io.dropwizard:dropwizard-jackson")
-    implementation(libs.h2) // Different dependencies will be needed for different backend databases
-
-    testImplementation(libs.h2)
-    testImplementation(testFixtures(project(":polaris-core")))
+plugins { `kotlin-dsl` }
 
-    sourceSets {
-        test {
-            resources {
-                srcDir 'src/test/data'
-            }
-        }
-    }
+dependencies {
+  implementation(gradleKotlinDsl())
+  implementation(baselibs.errorprone)
+  implementation(baselibs.idea.ext)
+  implementation(baselibs.spotless)
 }

settings.gradle renamed to build-logic/settings.gradle.kts

@@ -14,25 +14,14 @@
  * limitations under the License.
  */
 
-if (!JavaVersion.current().isCompatibleWith(JavaVersion.VERSION_21)) {
-    throw new GradleException("""
-
-        Build aborted...
-
-        The Apache Polaris build requires Java 21.
-
-
-        """)
+dependencyResolutionManagement {
+  versionCatalogs { create("baselibs") { from(files("../gradle/baselibs.versions.toml")) } }
 }
 
-rootProject.name = "polaris"
-
-Properties projects = new Properties()
-file("gradle/projects.main.properties").withInputStream { projects.load(it) }
-projects.entrySet().forEach {
-    final def name = it.key as String
-    include(name)
-    final def prj = project(":${name}")
-    prj.name = name
-    prj.projectDir = file(it.value)
+dependencyResolutionManagement {
+  repositoriesMode = RepositoriesMode.FAIL_ON_PROJECT_REPOS
+  repositories {
+    mavenCentral()
+    gradlePluginPortal()
+  }
 }

build-logic/src/main/kotlin/polaris-root.gradle.kts

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2024 Snowflake Computing Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import org.jetbrains.gradle.ext.copyright
+import org.jetbrains.gradle.ext.encodings
+import org.jetbrains.gradle.ext.settings
+
+plugins {
+  id("com.diffplug.spotless")
+  id("org.jetbrains.gradle.plugin.idea-ext")
+}
+
+spotless {
+  kotlinGradle {
+    ktfmt().googleStyle()
+    licenseHeaderFile(rootProject.file("codestyle/copyright-header-java.txt"), "$")
+    target("*.gradle.kts", "build-logic/src/**/*.kts")
+  }
+}
+
+if (System.getProperty("idea.sync.active").toBoolean()) {
+  idea {
+    module {
+      isDownloadJavadoc = false // was 'true', but didn't work
+      isDownloadSources = false // was 'true', but didn't work
+      inheritOutputDirs = true
+    }
+
+    project.settings {
+      copyright {
+        useDefault = "ApacheLicense-v2"
+        profiles.create("ApacheLicense-v2") {
+          // strip trailing LF
+          val copyrightText = rootProject.file("codestyle/copyright-header.txt").readText()
+          notice = copyrightText
+        }
+      }
+
+      encodings.encoding = "UTF-8"
+      encodings.properties.encoding = "UTF-8"
+    }
+  }
+}

build-logic/src/main/kotlin/polaris-server.gradle.kts

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2024 Snowflake Computing Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import net.ltgt.gradle.errorprone.errorprone
+import org.gradle.api.tasks.compile.JavaCompile
+import org.gradle.api.tasks.testing.Test
+import org.gradle.kotlin.dsl.named
+
+plugins {
+  id("jacoco")
+  id("java")
+  id("com.diffplug.spotless")
+  id("jacoco-report-aggregation")
+  id("net.ltgt.errorprone")
+}
+
+tasks.withType(JavaCompile::class.java).configureEach {
+  options.compilerArgs.addAll(listOf("-Xlint:unchecked", "-Xlint:deprecation"))
+  options.errorprone.disableAllWarnings = true
+  options.errorprone.disableWarningsInGeneratedCode = true
+  options.errorprone.error("StringCaseLocaleUsage")
+
+  // TODO Disabled until the code is only Java 11/17/21, see #76
+  // options.release = 17
+}
+
+tasks.register("format").configure { dependsOn("spotlessApply") }
+
+tasks.named<Test>("test").configure {
+  useJUnitPlatform()
+  jvmArgs("-Duser.language=en")
+}
+
+spotless {
+  val disallowWildcardImports = { text: String ->
+    val regex = "~/import .*\\.\\*;/".toRegex()
+    if (regex.matches(text)) {
+      throw GradleException("Wildcard imports disallowed - ${regex.findAll(text)}")
+    }
+    text
+  }
+  java {
+    target("src/main/java/**/*.java", "src/testFixtures/java/**/*.java", "src/test/java/**/*.java")
+    googleJavaFormat()
+    licenseHeaderFile(rootProject.file("codestyle/copyright-header-java.txt"))
+    endWithNewline()
+    custom("disallowWildcardImports", disallowWildcardImports)
+  }
+  kotlinGradle {
+    ktfmt().googleStyle()
+    licenseHeaderFile(rootProject.file("codestyle/copyright-header-java.txt"), "$")
+    target("*.gradle.kts")
+  }
+  format("xml") {
+    target("src/**/*.xml", "src/**/*.xsd")
+    targetExclude("codestyle/copyright-header.xml")
+    eclipseWtp(com.diffplug.spotless.extra.wtp.EclipseWtpFormatterStep.XML)
+      .configFile(rootProject.file("codestyle/org.eclipse.wst.xml.core.prefs"))
+    // getting the license-header delimiter right is a bit tricky.
+    // licenseHeaderFile(rootProject.file("codestyle/copyright-header.xml"), '<^[!?].*$')
+  }
+}
+
+dependencies { errorprone(versionCatalogs.named("libs").findLibrary("errorprone").get()) }