Hide implementation details

Author: marcphilipp

junit-platform-launcher/src/main/java/org/junit/platform/launcher/LauncherInterceptor.java

@@ -11,9 +11,6 @@
 package org.junit.platform.launcher;
 
 import static org.apiguardian.api.API.Status.EXPERIMENTAL;
-import static org.apiguardian.api.API.Status.INTERNAL;
-
-import java.util.List;
 
 import org.apiguardian.api.API;
 
@@ -58,18 +55,6 @@
 @API(status = EXPERIMENTAL, since = "1.10")
 public interface LauncherInterceptor {
 
-	LauncherInterceptor NOOP = new LauncherInterceptor() {
-		@Override
-		public <T> T intercept(Invocation<T> invocation) {
-			return invocation.proceed();
-		}
-
-		@Override
-		public void close() {
-			// do nothing
-		}
-	};
-
 	/**
 	 * Intercept the supplied invocation.
 	 *
@@ -97,28 +82,4 @@ interface Invocation<T> {
 		T proceed();
 	}
 
-	@API(status = INTERNAL, since = "1.10")
-	static LauncherInterceptor composite(List<LauncherInterceptor> interceptors) {
-		if (interceptors.isEmpty()) {
-			return NOOP;
-		}
-		return interceptors.stream() //
-				.skip(1) //
-				.reduce(interceptors.get(0), (a, b) -> new LauncherInterceptor() {
-					@Override
-					public void close() {
-						try {
-							a.close();
-						}
-						finally {
-							b.close();
-						}
-					}
-
-					@Override
-					public <T> T intercept(Invocation<T> invocation) {
-						return a.intercept(() -> b.intercept(invocation));
-					}
-				});
-	}
 }

junit-platform-launcher/src/main/java/org/junit/platform/launcher/core/DefaultLauncherSession.java

@@ -28,15 +28,27 @@
  */
 class DefaultLauncherSession implements LauncherSession {
 
+	private static final LauncherInterceptor NOOP_INTERCEPTOR = new LauncherInterceptor() {
+		@Override
+		public <T> T intercept(Invocation<T> invocation) {
+			return invocation.proceed();
+		}
+
+		@Override
+		public void close() {
+			// do nothing
+		}
+	};
+
 	private final LauncherInterceptor interceptor;
 	private final LauncherSessionListener listener;
 	private final DelegatingLauncher launcher;
 
 	DefaultLauncherSession(List<LauncherInterceptor> interceptors, Supplier<LauncherSessionListener> listenerSupplier,
 			Supplier<Launcher> launcherSupplier) {
-		interceptor = LauncherInterceptor.composite(interceptors);
+		interceptor = composite(interceptors);
 		Launcher launcher;
-		if (interceptor == LauncherInterceptor.NOOP) {
+		if (interceptor == NOOP_INTERCEPTOR) {
 			this.listener = listenerSupplier.get();
 			launcher = launcherSupplier.get();
 		}
@@ -98,4 +110,28 @@ public void execute(TestPlan testPlan, TestExecutionListener... listeners) {
 			throw new PreconditionViolationException("Launcher session has already been closed");
 		}
 	}
+
+	private static LauncherInterceptor composite(List<LauncherInterceptor> interceptors) {
+		if (interceptors.isEmpty()) {
+			return NOOP_INTERCEPTOR;
+		}
+		return interceptors.stream() //
+				.skip(1) //
+				.reduce(interceptors.get(0), (a, b) -> new LauncherInterceptor() {
+					@Override
+					public void close() {
+						try {
+							a.close();
+						}
+						finally {
+							b.close();
+						}
+					}
+
+					@Override
+					public <T> T intercept(Invocation<T> invocation) {
+						return a.intercept(() -> b.intercept(invocation));
+					}
+				});
+	}
 }