1 files changed, 52 insertions, 0 deletions
diff --git a/src/test/java/org/apache/commons/compress/compressors/zstandard/ZstdUtilsTest.java b/src/test/java/org/apache/commons/compress/compressors/zstandard/ZstdUtilsTest.java
new file mode 100644
index 000000000..5bba0ad58
--- /dev/null
+++ b/src/test/java/org/apache/commons/compress/compressors/zstandard/ZstdUtilsTest.java
@@ -0,0 +1,52 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.compress.compressors.zstandard;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class ZstdUtilsTest {
+
+    @Test
+    public void testMatchesZstandardFrame() {
+        final byte[] data = {
+            (byte) 0x28, (byte) 0xB5, (byte) 0x2F, (byte) 0xFD,
+        };
+        assertFalse(ZstdUtils.matches(data, 3));
+        assertTrue(ZstdUtils.matches(data, 4));
+        assertTrue(ZstdUtils.matches(data, 5));
+        data[3] = '0';
+        assertFalse(ZstdUtils.matches(data, 4));
+    }
+
+    @Test
+    public void testMatchesSkippableFrame() {
+        final byte[] data = {
+            0, (byte) 0x2A, (byte) 0x4D, (byte) 0x18,
+        };
+        assertFalse(ZstdUtils.matches(data, 4));
+        for (byte b = (byte) 0x50; b < 0x60; b++) {
+            data[0] = b;
+            assertTrue(ZstdUtils.matches(data, 4));
+        }
+        assertFalse(ZstdUtils.matches(data, 3));
+        assertTrue(ZstdUtils.matches(data, 5));
+    }
+}