added tests for cache package

Author: tacoo

src/test/java/org/apache/ibatis/cache/CacheKeyTest.java

@@ -24,7 +24,6 @@
 import java.io.ObjectOutputStream;
 import java.util.Date;
 
-import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
 class CacheKeyTest {
@@ -87,11 +86,31 @@ void shouldTestCacheKeysWithBinaryArrays() {
     assertEquals(key1, key2);
   }
 
+  @Test
+  void throwExceptionWhenTryingToUpdateNullCacheKey() {
+    CacheKey cacheKey = CacheKey.NULL_CACHE_KEY;
+    assertThrows(CacheException.class, () -> cacheKey.update("null"));
+  }
+
+  @Test
+  void throwExceptionWhenTryingToUpdateAllNullCacheKey() {
+    CacheKey cacheKey = CacheKey.NULL_CACHE_KEY;
+    assertThrows(CacheException.class, () -> cacheKey.updateAll(new Object[]{"null", "null"}));
+  }
+
+  @Test
+  void shouldDemonstrateClonedNullCacheKeysAreEqual() throws Exception {
+    CacheKey cacheKey = CacheKey.NULL_CACHE_KEY;
+    CacheKey clonedCacheKey = cacheKey.clone();
+    assertEquals(cacheKey, clonedCacheKey);
+    assertEquals(cacheKey.hashCode(), clonedCacheKey.hashCode());
+  }
+
   @Test
   void serializationExceptionTest() {
     CacheKey cacheKey = new CacheKey();
     cacheKey.update(new Object());
-    Assertions.assertThrows(NotSerializableException.class, () -> {
+    assertThrows(NotSerializableException.class, () -> {
       serialize(cacheKey);
     });
   }
@@ -100,7 +119,7 @@ void serializationExceptionTest() {
   void serializationTest() throws Exception {
     CacheKey cacheKey = new CacheKey();
     cacheKey.update("serializable");
-    Assertions.assertEquals(cacheKey, serialize(cacheKey));
+    assertEquals(cacheKey, serialize(cacheKey));
   }
 
   private static <T> T serialize(T object) throws Exception {

src/test/java/org/apache/ibatis/cache/PerpetualCacheTest.java

@@ -69,4 +69,10 @@ void shouldFlushAllItemsOnDemand() {
     assertNull(cache.getObject(4));
   }
 
+  @Test
+  void shouldDemonstrateIdIsNull() {
+    Cache cache = new PerpetualCache(null);
+    assertThrows(CacheException.class, () -> cache.hashCode());
+    assertThrows(CacheException.class, () -> cache.equals(new Object()));
+  }
 }

src/test/java/org/apache/ibatis/cache/SerializedCacheTest.java

@@ -0,0 +1,85 @@
+package org.apache.ibatis.cache;
+
+import org.apache.ibatis.cache.decorators.SerializedCache;
+import org.apache.ibatis.cache.impl.PerpetualCache;
+import org.junit.jupiter.api.Test;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class SerializedCacheTest {
+
+  @Test
+  void shouldDemonstrateSerializedObjectAreEqual() {
+    SerializedCache cache = new SerializedCache(new PerpetualCache("default"));
+    for (int i = 0; i < 5; i++) {
+      cache.putObject(i, new CachingObject(i));
+    }
+    for (int i = 0; i < 5; i++) {
+      assertEquals(new CachingObject(i), cache.getObject(i));
+    }
+  }
+
+  @Test
+  void shouldDemonstrateNullsAreSerializable() {
+    SerializedCache cache = new SerializedCache(new PerpetualCache("default"));
+    for (int i = 0; i < 5; i++) {
+      cache.putObject(i, null);
+    }
+    for (int i = 0; i < 5; i++) {
+      assertEquals(null, cache.getObject(i));
+    }
+  }
+
+  @Test
+  void throwExceptionWhenTryingToCacheNonSerializableObject() {
+    SerializedCache cache = new SerializedCache(new PerpetualCache("default"));
+    assertThrows(CacheException.class,
+      () -> cache.putObject(0, new CachingObjectWithoutSerializable(0)));
+  }
+
+  static class CachingObject implements Serializable {
+    int x;
+
+    public CachingObject(int x) {
+      this.x = x;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      CachingObject obj = (CachingObject) o;
+      return x == obj.x;
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(x);
+    }
+  }
+
+  static class CachingObjectWithoutSerializable {
+    int x;
+
+    public CachingObjectWithoutSerializable(int x) {
+      this.x = x;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      CachingObjectWithoutSerializable obj = (CachingObjectWithoutSerializable) o;
+      return x == obj.x;
+    }
+
+    @Override
+    public int hashCode() {
+      return Objects.hash(x);
+    }
+  }
+}