fix: use try-with-resources for ObjectOutputStream to ensure all the data is written

Previously, ObjectOutputStream could silently buffer data in the internal buffers

Author: Vladimir Sitnikov

api/src/main/java/net/jqwik/api/support/LambdaSupport.java

@@ -92,8 +92,9 @@ public static <T> boolean areEqual(T l1, T l2) {
 
 	private static <T> byte[] serialize(T l1) throws IOException {
 		ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
-		ObjectOutputStream outputStream = new ObjectOutputStream(byteArrayOutputStream);
-		outputStream.writeObject(l1);
+		try (ObjectOutputStream outputStream = new ObjectOutputStream(byteArrayOutputStream);) {
+			outputStream.writeObject(l1);
+		}
 		return byteArrayOutputStream.toByteArray();
 	}
 

engine/src/test/java/net/jqwik/engine/execution/GenerationInfoTests.java

@@ -162,7 +162,9 @@ void resetByteArrayOutputStream() {
 		void serializeWithEmptyShrinkingSequence() throws Exception {
 			GenerationInfo generationInfo = new GenerationInfo("4242", 41);
 
-			outputStream().writeObject(generationInfo);
+			try (ObjectOutputStream os = outputStream();) {
+				os.writeObject(generationInfo);
+			}
 
 			// System.out.println("### size: " + byteArrayOutputStream.toByteArray().length);
 
@@ -175,7 +177,9 @@ void serializeWithShortShrinkingSequence(@ForAll("shrinkingSequence") @Size(max
 			GenerationInfo generationInfo = new GenerationInfo("4242", 41)
 				.appendShrinkingSequence(sequence);
 
-			outputStream().writeObject(generationInfo);
+			try (ObjectOutputStream os = outputStream();) {
+				os.writeObject(generationInfo);
+			}
 
 			// System.out.println("### size: " + byteArrayOutputStream.toByteArray().length);
 
@@ -190,7 +194,9 @@ void serializeWithSeveralShrinkingSequences(@ForAll @Size(3) List<@Size(max = 10
 				generationInfo = generationInfo.appendShrinkingSequence(sequence);
 			}
 
-			outputStream().writeObject(generationInfo);
+			try (ObjectOutputStream os = outputStream();) {
+				os.writeObject(generationInfo);
+			}
 
 			// System.out.println("### size: " + byteArrayOutputStream.toByteArray().length);
 
@@ -203,7 +209,9 @@ void serializeWithLongShrinkingSequence(@ForAll("shrinkingSequence") @Size(min =
 			GenerationInfo generationInfo = new GenerationInfo("4242", 41)
 				.appendShrinkingSequence(sequence);
 
-			outputStream().writeObject(generationInfo);
+			try (ObjectOutputStream os = outputStream();) {
+				os.writeObject(generationInfo);
+			}
 
 			// System.out.printf("### size: %s (%s)%n", sequence.size(), byteArrayOutputStream.toByteArray().length);