From 8c1c6f8a58a98ab45d08b8c6391ffeef3cefc5eb Mon Sep 17 00:00:00 2001
From: Joshua Barr <jobarr@amazon.com>
Date: Fri, 26 Jan 2024 12:34:40 -0800
Subject: [PATCH] Add test coverage for maximum buffer size

---
 .../ion/impl/ResizingPipedInputStream.java     |  2 +-
 .../amazon/ion/impl/_Private_IonConstants.java |  3 ++-
 .../ion/impl/ResizingPipedInputStreamTest.java | 18 ++++++++++--------
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/main/java/com/amazon/ion/impl/ResizingPipedInputStream.java b/src/main/java/com/amazon/ion/impl/ResizingPipedInputStream.java
index dd09fd1715..16826d753d 100644
--- a/src/main/java/com/amazon/ion/impl/ResizingPipedInputStream.java
+++ b/src/main/java/com/amazon/ion/impl/ResizingPipedInputStream.java
@@ -152,7 +152,7 @@ public ResizingPipedInputStream(final int initialBufferSize) {
         if (initialBufferSize < 1) {
             throw new IllegalArgumentException("Initial buffer size must be at least 1.");
         }
-        if (initialBufferSize > _Private_IonConstants.ARRAY_MAXIMUM_SIZE) {
+        if (maximumBufferSize > _Private_IonConstants.ARRAY_MAXIMUM_SIZE) {
             throw new IllegalArgumentException("Initial buffer size must be at most " + _Private_IonConstants.ARRAY_MAXIMUM_SIZE + ".");
         }
         if (maximumBufferSize < initialBufferSize) {
diff --git a/src/main/java/com/amazon/ion/impl/_Private_IonConstants.java b/src/main/java/com/amazon/ion/impl/_Private_IonConstants.java
index e0fe8cc0c3..d7c706b36d 100644
--- a/src/main/java/com/amazon/ion/impl/_Private_IonConstants.java
+++ b/src/main/java/com/amazon/ion/impl/_Private_IonConstants.java
@@ -26,7 +26,8 @@ public final class _Private_IonConstants
     // Integer.MAX_VALUE. True maximum array size is a JVM implementation detail, and varies by type and by JVM.
     // We have this pinned at Integer.MAX_VALUE - 8 because that's a fairly common value in the JDK itself, in
     // classes such as ConcurrentHashMap, InputStream, Hashtable, ByteArrayChannel, etc.
-    // In testing against a variety of JVMs and types the smallest maximum size I've seen is Integer.MAX_VALUE - 6
+    // In testing against a variety of JVMs and types the smallest maximum size I've seen is Integer.MAX_VALUE - 2,
+    // and the smallest maximum size I've seen reported is Integer.MAX_VALUE - 6.
     public static final int ARRAY_MAXIMUM_SIZE = Integer.MAX_VALUE - 8;
 
     private _Private_IonConstants() { }
diff --git a/src/test/java/com/amazon/ion/impl/ResizingPipedInputStreamTest.java b/src/test/java/com/amazon/ion/impl/ResizingPipedInputStreamTest.java
index d3d12d4ebb..00acac82b7 100644
--- a/src/test/java/com/amazon/ion/impl/ResizingPipedInputStreamTest.java
+++ b/src/test/java/com/amazon/ion/impl/ResizingPipedInputStreamTest.java
@@ -21,11 +21,9 @@
 import java.util.zip.GZIPOutputStream;
 
 import static com.amazon.ion.BitUtils.bytes;
-import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.*;
 import static org.junit.runners.Parameterized.Parameter;
 import static org.junit.runners.Parameterized.Parameters;
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertEquals;
 
 @RunWith(Parameterized.class)
 public class ResizingPipedInputStreamTest {
@@ -469,16 +467,20 @@ public void truncate() throws Exception {
         assertEquals(0, input.available());
     }
 
-    @Test(expected = IllegalArgumentException.class)
+    @Test
     public void errorsOnInvalidInitialBufferSize() {
-        new ResizingPipedInputStream(0);
+        assertThrows(IllegalArgumentException.class, () -> new ResizingPipedInputStream(0));
     }
 
-    @Test(expected = IllegalArgumentException.class)
-    public void errorsOnInvalidMaximumBufferSize() {
-        new ResizingPipedInputStream(10, 9, useBoundary);
+    @Test
+    public void errorsOnMaximumBufferSizeSmallerThanInitialSize() {
+        assertThrows(IllegalArgumentException.class, () -> new ResizingPipedInputStream(10, 9, useBoundary));
     }
 
+    @Test
+    public void errorsOnInvalidMaximumBufferSize() {
+        assertThrows(IllegalArgumentException.class, () -> new ResizingPipedInputStream(10, Integer.MAX_VALUE, useBoundary));
+    }
     @Test
     public void initialBufferSizeAndCapacity() {
         assertEquals(bufferSize, input.getInitialBufferSize());