Update the hash function tests to use a base class.

The base class performs the standard signature test that all hash
functions should pass.

src/test/java/org/apache/commons/collections4/bloomfilter/hasher/function/AbstractHashFunctionTest.java

@@ -0,0 +1,50 @@
+/*
+ * 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.collections4.bloomfilter.hasher.function;
+
+import static org.junit.Assert.assertEquals;
+
+import org.apache.commons.collections4.bloomfilter.hasher.HashFunction;
+import org.apache.commons.collections4.bloomfilter.hasher.HashFunctionIdentity;
+import org.junit.Test;
+
+/**
+ * Tests the signature of a hash function.
+ */
+public abstract class AbstractHashFunctionTest {
+
+    /**
+     * Test that the signature is properly generated.
+     */
+    @Test
+    public void signatureTest() {
+        final HashFunction hf = createHashFunction();
+        final long expected = hf.apply(HashFunctionIdentity.prepareSignatureBuffer(hf), 0);
+        assertEquals(expected, hf.getSignature());
+        // Should be repeatable
+        final long expected2 = hf.apply(HashFunctionIdentity.prepareSignatureBuffer(hf), 0);
+        assertEquals(expected, expected2);
+        assertEquals("Apache Commons Collections", hf.getProvider());
+    }
+
+    /**
+     * Creates the hash function.
+     *
+     * @return the hash function
+     */
+    protected abstract HashFunction createHashFunction();
+}

src/test/java/org/apache/commons/collections4/bloomfilter/hasher/function/MD5CyclicTest.java

@@ -18,15 +18,13 @@ package org.apache.commons.collections4.bloomfilter.hasher.function;
 
 import static org.junit.Assert.assertEquals;
 
-import java.nio.charset.StandardCharsets;
-import java.util.Locale;
-
+import org.apache.commons.collections4.bloomfilter.hasher.HashFunction;
 import org.junit.Test;
 
 /**
  * Tests the MD5 cyclic hash function.
  */
-public class MD5CyclicTest {
+public class MD5CyclicTest extends AbstractHashFunctionTest {
 
     /**
      * Test that the apply function returns the proper values.
@@ -46,16 +44,8 @@ public class MD5CyclicTest {
         assertEquals(l1 + l2 + l2, l);
     }
 
-    /**
-     * Test that the signature is properly generated.
-     */
-    @Test
-    public void signatureTest() {
-        final MD5Cyclic md5 = new MD5Cyclic();
-        final String arg = String.format("%s-%s-%s", md5.getName().toUpperCase(Locale.ROOT), md5.getSignedness(),
-            md5.getProcessType());
-        final long expected = md5.apply(arg.getBytes(StandardCharsets.UTF_8), 0);
-        assertEquals(expected, md5.getSignature());
-        assertEquals("Apache Commons Collections", md5.getProvider());
+    @Override
+    protected HashFunction createHashFunction() {
+        return new MD5Cyclic();
     }
 }

src/test/java/org/apache/commons/collections4/bloomfilter/hasher/function/Murmur128x86CyclicTest.java

@@ -19,14 +19,13 @@ package org.apache.commons.collections4.bloomfilter.hasher.function;
 import static org.junit.Assert.assertEquals;
 
 import java.nio.charset.StandardCharsets;
-import java.util.Locale;
-
+import org.apache.commons.collections4.bloomfilter.hasher.HashFunction;
 import org.junit.Test;
 
 /**
  * Test that the Murmur3 128 x86 hash function works correctly.
  */
-public class Murmur128x86CyclicTest {
+public class Murmur128x86CyclicTest extends AbstractHashFunctionTest {
 
     /**
      * Test that the apply function returns the proper values.
@@ -48,16 +47,8 @@ public class Murmur128x86CyclicTest {
         assertEquals(l1 + l2 + l2, l);
     }
 
-    /**
-     * Test that the signature is properly generated.
-     */
-    @Test
-    public void signatureTest() {
-        final Murmur128x86Cyclic murmur = new Murmur128x86Cyclic();
-        final String arg = String.format("%s-%s-%s", murmur.getName().toUpperCase(Locale.ROOT), murmur.getSignedness(),
-            murmur.getProcessType());
-        final long expected = murmur.apply(arg.getBytes(StandardCharsets.UTF_8), 0);
-        assertEquals(expected, murmur.getSignature());
-        assertEquals("Apache Commons Collections", murmur.getProvider());
+    @Override
+    protected HashFunction createHashFunction() {
+        return new Murmur128x86Cyclic();
     }
 }

src/test/java/org/apache/commons/collections4/bloomfilter/hasher/function/Murmur32x86IterativeTest.java

@@ -19,14 +19,13 @@ package org.apache.commons.collections4.bloomfilter.hasher.function;
 import static org.junit.Assert.assertEquals;
 
 import java.nio.charset.StandardCharsets;
-import java.util.Locale;
-
+import org.apache.commons.collections4.bloomfilter.hasher.HashFunction;
 import org.junit.Test;
 
 /**
  * Test that the Murmur3 32 x86 hash function works correctly.
  */
-public class Murmur32x86IterativeTest {
+public class Murmur32x86IterativeTest extends AbstractHashFunctionTest {
 
     /**
      * Test that the apply function returns the proper values.
@@ -46,16 +45,8 @@ public class Murmur32x86IterativeTest {
         assertEquals(-1561435247, l);
     }
 
-    /**
-     * Test that the signature is properly generated.
-     */
-    @Test
-    public void signatureTest() {
-        final Murmur32x86Iterative murmur = new Murmur32x86Iterative();
-        final String arg = String.format("%s-%s-%s", murmur.getName().toUpperCase(Locale.ROOT), murmur.getSignedness(),
-            murmur.getProcessType());
-        final long expected = murmur.apply(arg.getBytes(StandardCharsets.UTF_8), 0);
-        assertEquals(expected, murmur.getSignature());
-        assertEquals("Apache Commons Collections", murmur.getProvider());
+    @Override
+    protected HashFunction createHashFunction() {
+        return new Murmur32x86Iterative();
     }
 }

src/test/java/org/apache/commons/collections4/bloomfilter/hasher/function/ObjectsHashIterativeTest.java

@@ -20,13 +20,13 @@ import static org.junit.Assert.assertEquals;
 
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
-import java.util.Locale;
+import org.apache.commons.collections4.bloomfilter.hasher.HashFunction;
 import org.junit.Test;
 
 /**
  * Tests that the Objects hash works correctly.
  */
-public class ObjectsHashIterativeTest {
+public class ObjectsHashIterativeTest extends AbstractHashFunctionTest {
 
     /**
      * Test that the apply function returns the proper values.
@@ -49,18 +49,8 @@ public class ObjectsHashIterativeTest {
         assertEquals(Arrays.deepHashCode(new Object[] {prev, buffer}), l);
     }
 
-    /**
-     * Test that the signature is properly generated.
-     */
-    @Test
-    public void signatureTest() {
-        final ObjectsHashIterative obj = new ObjectsHashIterative();
-        final String arg = String.format("%s-%s-%s", obj.getName().toUpperCase(Locale.ROOT), obj.getSignedness(),
-            obj.getProcessType());
-        final long expected = obj.apply(arg.getBytes(StandardCharsets.UTF_8), 0);
-        final long expected2 = obj.apply(arg.getBytes(StandardCharsets.UTF_8), 0);
-        assertEquals(expected, expected2);
-        assertEquals(expected, obj.getSignature());
-        assertEquals("Apache Commons Collections", obj.getProvider());
+    @Override
+    protected HashFunction createHashFunction() {
+        return new ObjectsHashIterative();
     }
 }