follow up of junit-team#2544 to enable a fully resolveable OSGi solution

What this means is that merely by consuming the Jupiter client APIs results in requiring a fully fleshed out runtime including launcher as follows
- junit-jupiter-api & junit-jupiter-params depend on junit-platform-commons
- junit-platform-commons Requires a org.junit.platform.engine=*
- junit-jupiter-engine Provides org.junit.platform.engine=junit-jupiter
- junit-vintage-engine Provides org.junit.platform.engine=junit-vintage
- junit-jupiter-engine & junit-vintage-engine Requires org.junit.platform.launcher=junit-platform-launcher
- junit-platform-launcher Provides org.junit.platform.launcher=junit-platform-launcher

The solution is solvable having either junit-jupiter OR junit-vintage on your test classpath

Signed-off-by: Raymond Augé <raymond.auge@liferay.com>

junit-jupiter-engine/junit-jupiter-engine.gradle.kts

@@ -23,6 +23,8 @@ dependencies {
 	testImplementation(kotlin("stdlib"))
 	testImplementation(libs.kotlinx.coroutines)
 	testImplementation(libs.groovy3)
+
+	runtimeOnly(projects.junitPlatformLauncher)
 }
 
 tasks {
@@ -39,6 +41,9 @@ tasks {
 					org.junit.platform.engine;\
 						org.junit.platform.engine='junit-jupiter';\
 						version:Version="${'$'}{version_cleanup;${project.version}}"
+				Require-Capability:\
+					org.junit.platform.launcher;\
+						filter:='(&(org.junit.platform.launcher=junit-platform-launcher)(version>=${'$'}{version_cleanup;${rootProject.property("platformVersion")!!}})(!(version>=${'$'}{versionmask;+;${'$'}{version_cleanup;${rootProject.property("platformVersion")!!}}})))'
 			""")
 		}
 	}

junit-platform-commons/junit-platform-commons.gradle.kts

@@ -1,3 +1,5 @@
+import aQute.bnd.gradle.BundleTaskConvention
+
 plugins {
 	`java-library-conventions`
 	`java-multi-release-sources`
@@ -11,11 +13,22 @@ dependencies {
 	api(platform(projects.junitBom))
 
 	compileOnlyApi(libs.apiguardian)
+
+	runtimeOnly(projects.junitJupiterEngine)
 }
 
 tasks.jar {
 	val release9ClassesDir = sourceSets.mainRelease9.get().output.classesDirs.singleFile
 	inputs.dir(release9ClassesDir).withPathSensitivity(PathSensitivity.RELATIVE)
+
+	withConvention(BundleTaskConvention::class) {
+		bnd("""
+			Require-Capability:\
+				org.junit.platform.engine;\
+					filter:='(&(org.junit.platform.engine=*)(version>=${'$'}{version_cleanup;${rootProject.property("version")!!}})(!(version>=${'$'}{versionmask;+;${'$'}{version_cleanup;${rootProject.property("version")!!}}})))'
+		""")
+	}
+
 	doLast {
 		exec {
 			executable = project.the<JavaToolchainService>().launcherFor(java.toolchain).get()

junit-platform-launcher/junit-platform-launcher.gradle.kts

@@ -1,3 +1,5 @@
+import aQute.bnd.gradle.BundleTaskConvention
+
 plugins {
 	`java-library-conventions`
 	`java-test-fixtures`
@@ -11,3 +13,16 @@ dependencies {
 
 	compileOnlyApi(libs.apiguardian)
 }
+
+tasks {
+	jar {
+		withConvention(BundleTaskConvention::class) {
+			bnd("""
+				Provide-Capability:\
+					org.junit.platform.launcher;\
+						org.junit.platform.launcher='junit-platform-launcher';\
+						version:Version="${'$'}{version_cleanup;${project.version}}"
+			""")
+		}
+	}
+}

junit-vintage-engine/junit-vintage-engine.gradle.kts

@@ -24,6 +24,8 @@ dependencies {
 	testImplementation(projects.junitPlatformLauncher)
 	testImplementation(projects.junitPlatformRunner)
 	testImplementation(projects.junitPlatformTestkit)
+
+	runtimeOnly(projects.junitPlatformLauncher)
 }
 
 tasks {
@@ -53,6 +55,9 @@ tasks {
 					org.junit.platform.engine;\
 						org.junit.platform.engine='junit-vintage';\
 						version:Version="${'$'}{version_cleanup;${project.version}}"
+				Require-Capability:\
+					org.junit.platform.launcher;\
+						filter:='(&(org.junit.platform.launcher=junit-platform-launcher)(version>=${'$'}{version_cleanup;${rootProject.property("platformVersion")!!}})(!(version>=${'$'}{versionmask;+;${'$'}{version_cleanup;${rootProject.property("platformVersion")!!}}})))'
 			""")
 		}
 	}