StoredBlockTest: add tests for serializeCompact(), deserializeCompact…

…(), moreWorkThan()

core/src/test/java/org/bitcoinj/core/StoredBlockTest.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright by the original author or authors.
+ *
+ * Licensed 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.bitcoinj.core;
+
+import org.junit.Test;
+
+import java.math.BigInteger;
+import java.nio.Buffer;
+import java.nio.ByteBuffer;
+import java.time.Instant;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class StoredBlockTest {
+
+    // Max chain work to fit in 12 bytes
+    private static final BigInteger VERY_LARGE_WORK = new BigInteger(/* 12 bytes */ "ffffffffffffffffffffffff", 16);
+    // Chain work too large to fit in 12 bytes
+    private static final BigInteger TOO_LARGE_WORK = new BigInteger(/* 13 bytes */ "ffffffffffffffffffffffffff", 16);
+    // Just an arbitrary block
+    private static final Block BLOCK = Block.createGenesis(Instant.now(), Block.EASIEST_DIFFICULTY_TARGET);
+
+    @Test
+    public void roundtripSerializeCompact_zeroChainWork() {
+        roundtripSerializeCompact(BigInteger.ZERO);
+    }
+
+    @Test
+    public void roundtripSerializeCompact_largeChainWork() {
+        roundtripSerializeCompact(BigInteger.valueOf(Long.MAX_VALUE));
+    }
+
+    @Test
+    public void roundtripSerializeCompact_veryLargeChainWork() {
+        roundtripSerializeCompact(VERY_LARGE_WORK);
+    }
+
+    @Test(expected = RuntimeException.class)
+    public void roundtripSerializeCompact_tooLargeChainWork_shouldFail() {
+        roundtripSerializeCompact(TOO_LARGE_WORK);
+    }
+
+    @Test(expected = RuntimeException.class)
+    public void roundtripSerializeCompact_negativeChainWork_shouldFail() {
+        roundtripSerializeCompact(BigInteger.valueOf(-1));
+    }
+
+    @Test
+    public void moreWorkThan() {
+        StoredBlock noWorkBlock = new StoredBlock(BLOCK, BigInteger.ZERO, 0);
+        StoredBlock smallWorkBlock = new StoredBlock(BLOCK, BigInteger.ONE, 0);
+        StoredBlock veryLargeWorkBlock = new StoredBlock(BLOCK, VERY_LARGE_WORK, 0);
+
+        assertTrue(smallWorkBlock.moreWorkThan(noWorkBlock));
+        assertTrue(veryLargeWorkBlock.moreWorkThan(noWorkBlock));
+        assertTrue(veryLargeWorkBlock.moreWorkThan(smallWorkBlock));
+    }
+
+    private void roundtripSerializeCompact(BigInteger chainWork) {
+        StoredBlock block = new StoredBlock(BLOCK, chainWork, 0);
+        ByteBuffer buf = ByteBuffer.allocate(StoredBlock.COMPACT_SERIALIZED_SIZE);
+        block.serializeCompact(buf);
+        assertEquals(StoredBlock.COMPACT_SERIALIZED_SIZE, buf.position());
+        ((Buffer) buf).rewind();
+        assertEquals(StoredBlock.deserializeCompact(buf), block);
+    }
+}