From a05fc05e567c411ff1fc249f7502aecd4e5786fd Mon Sep 17 00:00:00 2001
From: Andreas Schildbach <andreas@schildbach.de>
Date: Wed, 26 Jun 2024 23:14:02 +0200
Subject: [PATCH] StoredBlockTest: add tests for serializeCompact(),
 deserializeCompact(), moreWorkThan()

---
 .../org/bitcoinj/core/StoredBlockTest.java    | 89 +++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 core/src/test/java/org/bitcoinj/core/StoredBlockTest.java

diff --git a/core/src/test/java/org/bitcoinj/core/StoredBlockTest.java b/core/src/test/java/org/bitcoinj/core/StoredBlockTest.java
new file mode 100644
index 000000000..d516a43d6
--- /dev/null
+++ b/core/src/test/java/org/bitcoinj/core/StoredBlockTest.java
@@ -0,0 +1,89 @@
+/*
+ * 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 junitparams.JUnitParamsRunner;
+import junitparams.Parameters;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+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;
+
+@RunWith(JUnitParamsRunner.class)
+public class StoredBlockTest {
+
+    // Max chain work to fit in 12 bytes
+    private static final BigInteger MAX_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);
+
+    private Object[] vectors_serializeCompact_pass() {
+        return new Object[] {
+                new Object[] { BigInteger.ZERO }, // no work
+                new Object[] { BigInteger.ONE }, // small work
+                new Object[] { BigInteger.valueOf(Long.MAX_VALUE) }, // a larg-ish work
+                new Object[] { MAX_WORK },
+        };
+    }
+
+    @Test
+    @Parameters(method = "vectors_serializeCompact_pass")
+    public void roundtripSerializeCompact_pass(BigInteger chainWork) {
+        roundtripSerializeCompact(chainWork);
+    }
+
+    private Object[] vectors_serializeCompact_fail() {
+        return new Object[] {
+                new Object[] { TOO_LARGE_WORK },
+                new Object[] { BigInteger.valueOf(-1) }, // negative
+        };
+    }
+
+    @Test(expected = RuntimeException.class)
+    @Parameters(method = "vectors_serializeCompact_fail")
+    public void roundtripSerializeCompact_fail(BigInteger chainWork) {
+        roundtripSerializeCompact(chainWork);
+    }
+
+    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);
+    }
+
+    @Test
+    public void moreWorkThan() {
+        StoredBlock noWorkBlock = new StoredBlock(BLOCK, BigInteger.ZERO, 0);
+        StoredBlock smallWorkBlock = new StoredBlock(BLOCK, BigInteger.ONE, 0);
+        StoredBlock maxWorkBlock = new StoredBlock(BLOCK, MAX_WORK, 0);
+
+        assertTrue(smallWorkBlock.moreWorkThan(noWorkBlock));
+        assertTrue(maxWorkBlock.moreWorkThan(noWorkBlock));
+        assertTrue(maxWorkBlock.moreWorkThan(smallWorkBlock));
+    }
+}