Add BoundedInputStreamTest.testAvailable()

Author: garydgregory

src/test/java/org/apache/commons/io/input/BoundedInputStreamTest.java

@@ -23,6 +23,7 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.ByteArrayInputStream;
+import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -46,6 +47,17 @@ private void compare(final String message, final byte[] expected, final byte[] a
         }
     }
 
+    @SuppressWarnings("resource")
+    @Test
+    public void testAvailable() throws Exception {
+        final InputStream shadow;
+        try (InputStream in = BoundedInputStream.builder().setCharSequence("Hi").get()) {
+            assertTrue(in.available() > 0);
+            shadow = in;
+        }
+        assertEquals(0, shadow.available());
+    }
+
     @Test
     public void testBuilderGet() {
         // java.lang.IllegalStateException: origin == null