[build] Aggregated coverage report

build.gradle.kts

@@ -1,7 +1,27 @@
 plugins {
-    id("java")
-    id("maven-publish")
+	`jacoco-report-aggregation`
+	`maven-publish`
 }
 
 group = "de.siphalor.tweed5"
 version = properties["version"]!!
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	rootProject.subprojects.forEach { subproject ->
+		subproject.plugins.withId("jacoco") {
+			jacocoAggregation(project(subproject.path))
+		}
+	}
+}
+
+reporting {
+	reports {
+		val aggregatedCoverageReport by creating(JacocoCoverageReport::class) {
+			testSuiteName = "test"
+		}
+	}
+}