add UTs for VersionedCodecStreamWrapper

Signed-off-by: Varun Bansal <[email protected]>

Author: linuxpi

Diff for: server/src/test/java/org/opensearch/common/io/VersionedCodecStreamWrapperTests.java

@@ -0,0 +1,141 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.common.io;
+
+import org.apache.lucene.codecs.CodecUtil;
+import org.apache.lucene.index.CorruptIndexException;
+import org.apache.lucene.index.IndexFormatTooNewException;
+import org.apache.lucene.index.IndexFormatTooOldException;
+import org.apache.lucene.store.BufferedChecksumIndexInput;
+import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.store.OutputStreamIndexOutput;
+import org.junit.Before;
+import org.opensearch.common.bytes.BytesReference;
+import org.opensearch.common.io.stream.BytesStreamOutput;
+import org.opensearch.common.lucene.store.ByteArrayIndexInput;
+import org.opensearch.test.OpenSearchTestCase;
+
+import java.io.IOException;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * Unit tests for {@link org.opensearch.common.io.VersionedCodecStreamWrapper}.
+ */
+public class VersionedCodecStreamWrapperTests extends OpenSearchTestCase {
+
+    private static final String CODEC = "dummycodec";
+    private static final int VERSION = 1;
+
+    IndexIOStreamHandler<DummyObject> ioStreamHandler;
+    VersionedCodecStreamWrapper<DummyObject> versionedCodecStreamWrapper;
+
+    @Before
+    public void setup() throws IOException {
+        ioStreamHandler = mock(IndexIOStreamHandler.class);
+        versionedCodecStreamWrapper = new VersionedCodecStreamWrapper(ioStreamHandler, VERSION, CODEC);
+    }
+
+    public void testReadStream() throws IOException {
+        DummyObject expectedObject = new DummyObject("test read");
+        when(ioStreamHandler.readContent(any())).thenReturn(expectedObject);
+        DummyObject readData = versionedCodecStreamWrapper.readStream(createHeaderFooterBytes(CODEC, VERSION, true, true));
+        assertEquals(readData, expectedObject);
+    }
+
+    public void testReadWithOldVersionThrowsException() throws IOException {
+        DummyObject expectedObject = new DummyObject("test read");
+        when(ioStreamHandler.readContent(any())).thenReturn(expectedObject);
+        assertThrows(
+            IndexFormatTooOldException.class,
+            () -> versionedCodecStreamWrapper.readStream(createHeaderFooterBytes(CODEC, 0, true, true))
+        );
+    }
+
+    public void testReadWithNewVersionThrowsException() throws IOException {
+        DummyObject expectedObject = new DummyObject("test read");
+        when(ioStreamHandler.readContent(any())).thenReturn(expectedObject);
+        assertThrows(
+            IndexFormatTooNewException.class,
+            () -> versionedCodecStreamWrapper.readStream(createHeaderFooterBytes(CODEC, 2, true, true))
+        );
+    }
+
+    public void testReadWithUnexpectedCodecThrowsException() throws IOException {
+        DummyObject expectedObject = new DummyObject("test read");
+        when(ioStreamHandler.readContent(any())).thenReturn(expectedObject);
+        assertThrows(
+            CorruptIndexException.class,
+            () -> versionedCodecStreamWrapper.readStream(createHeaderFooterBytes("wrong codec", VERSION, true, true))
+        );
+    }
+
+    public void testReadWithNoHeaderThrowsException() throws IOException {
+        DummyObject expectedObject = new DummyObject("test read");
+        when(ioStreamHandler.readContent(any())).thenReturn(expectedObject);
+        assertThrows(
+            CorruptIndexException.class,
+            () -> versionedCodecStreamWrapper.readStream(createHeaderFooterBytes("wrong codec", VERSION, false, true))
+        );
+    }
+
+    public void testReadWithNoFooterThrowsException() throws IOException {
+        DummyObject expectedObject = new DummyObject("test read");
+        when(ioStreamHandler.readContent(any())).thenReturn(expectedObject);
+        assertThrows(
+            CorruptIndexException.class,
+            () -> versionedCodecStreamWrapper.readStream(createHeaderFooterBytes("wrong codec", VERSION, true, false))
+        );
+    }
+
+    public void testWriteStream() throws IOException {
+        DummyObject expectedObject = new DummyObject("test read");
+        BytesStreamOutput output = new BytesStreamOutput();
+        OutputStreamIndexOutput indexOutput = new OutputStreamIndexOutput("dummy bytes", "dummy stream", output, 4096);
+        doAnswer(invocation -> {
+            IndexOutput io = invocation.getArgument(0);
+            io.writeString("test write");
+            return null;
+        }).when(ioStreamHandler).writeContent(indexOutput, expectedObject);
+        versionedCodecStreamWrapper.writeStream(indexOutput, expectedObject);
+        indexOutput.close();
+        IndexInput indexInput = new ByteArrayIndexInput("dummy bytes", BytesReference.toBytes(output.bytes()));
+        BufferedChecksumIndexInput bii = new BufferedChecksumIndexInput(indexInput);
+
+        CodecUtil.checkHeader(bii, CODEC, VERSION, VERSION);
+        assertEquals(bii.readString(), "test write");
+        CodecUtil.checkFooter(bii);
+    }
+
+    private ByteArrayIndexInput createHeaderFooterBytes(String codec, int version, boolean writeHeader, boolean writeFooter)
+        throws IOException {
+        BytesStreamOutput output = new BytesStreamOutput();
+        OutputStreamIndexOutput indexOutput = new OutputStreamIndexOutput("dummy bytes", "dummy stream", output, 4096);
+        if (writeHeader) {
+            CodecUtil.writeHeader(indexOutput, codec, version);
+        }
+        if (writeFooter) {
+            CodecUtil.writeFooter(indexOutput);
+        }
+        indexOutput.close();
+        return new ByteArrayIndexInput("dummy bytes", BytesReference.toBytes(output.bytes()));
+    }
+
+    private static class DummyObject {
+        private static String dummyString;
+
+        public DummyObject(String dummy) {
+            dummyString = dummy;
+        }
+    }
+}