fix: correct data-mask and date-format bugs; add unit tests

.gitignore

@@ -33,3 +33,6 @@ build/
 .vscode/
 **/**/.flattened-pom.xml
 ./.flattened-pom.xml
+
+### Reasonix ###
+.reasonix/

pom.xml

@@ -57,6 +57,13 @@
             <scope>provided</scope>
         </dependency>
 
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>5.10.2</version>
+            <scope>test</scope>
+        </dependency>
+
     </dependencies>
     <licenses>
         <license>
@@ -82,6 +89,12 @@
                 </configuration>
             </plugin>
 
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>3.2.5</version>
+            </plugin>
+
             <plugin>
                 <artifactId>maven-jar-plugin</artifactId>
                 <version>${maven.jar.plugin.version}</version>

src/main/java/com/openquartz/javaobjdiff/DiffComparable.java

@@ -8,11 +8,11 @@
 public interface DiffComparable {
 
     /**
-     * 是否不同
+     * 是否相同
      *
      * @param source source
      * @param target target
-     * @return 是否不同,false: 相同, true: 不同
+     * @return 是否相同, true: 相同, false: 不同
      */
     boolean diff(Object source, Object target);
 }

src/main/java/com/openquartz/javaobjdiff/formatter/DateTimeDiffFormatter.java

@@ -1,7 +1,6 @@
 package com.openquartz.javaobjdiff.formatter;
 
 import com.openquartz.javaobjdiff.DiffFormatter;
-import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.time.temporal.TemporalAccessor;
 import java.util.Date;
@@ -34,7 +33,7 @@ public Object format(Object value, String pattern) {
         }
 
         if (value instanceof TemporalAccessor) {
-            return DateTimeFormatter.ofPattern(pattern).format((LocalDateTime) value);
+            return DateTimeFormatter.ofPattern(pattern).format((TemporalAccessor) value);
         }
 
         throw new IllegalArgumentException("Unsupported type: " + value.getClass());

src/main/java/com/openquartz/javaobjdiff/formatter/datamask/EmailDataMaskFormatter.java

@@ -34,14 +34,18 @@ public static String desensitizeEmail(String email) {
         }
 
         int atIndex = email.indexOf("@");
+        if (atIndex == 0) {
+            return email;
+        }
+
         String prefix = email.substring(0, atIndex);
         int lengthToReplace = prefix.length() - 1;
 
         String replacement = Stream.generate(() -> "*")
             .limit(lengthToReplace)
             .collect(Collectors.joining());
 
-        return replacement + prefix.charAt(0) + "@" + email.substring(atIndex);
+        return replacement + prefix.charAt(0) + email.substring(atIndex);
     }
 
 }

src/main/java/com/openquartz/javaobjdiff/formatter/datamask/MobileDataMaskFormatter.java

@@ -31,6 +31,9 @@ public Object format(Object value, String pattern) {
     }
 
     public static String desensitizePhoneNumber(String phoneNumber) {
+        if (phoneNumber == null) {
+            return null;
+        }
         if (MOBILE_PATTERN.matcher(phoneNumber).matches()) {
             // 手机号码脱敏处理
             return phoneNumber.substring(0, 3) + "****" + phoneNumber.substring(7);

src/test/java/com/openquartz/javaobjdiff/DiffUtilsTest.java

@@ -0,0 +1,277 @@
+package com.openquartz.javaobjdiff;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import com.openquartz.javaobjdiff.test.bean.Address;
+import com.openquartz.javaobjdiff.test.bean.Packet;
+import com.openquartz.javaobjdiff.test.bean.Person;
+import com.openquartz.javaobjdiff.test.bean.Sex;
+import java.math.BigDecimal;
+import java.time.LocalDateTime;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+/**
+ * DiffUtils 核心功能单元测试
+ *
+ * @author svnee
+ */
+public class DiffUtilsTest {
+
+    private Person person(String name, Integer age, Sex sex, Address address) {
+        Person person = new Person();
+        person.setName(name);
+        person.setAge(age);
+        person.setSex(sex);
+        person.setAddress(address);
+        return person;
+    }
+
+    private Address address(String country, String city) {
+        Address address = new Address();
+        address.setCountry(country);
+        address.setCity(city);
+        return address;
+    }
+
+    @Test
+    public void testSameReferenceNoDiff() {
+        Person person = person("jack", 10, Sex.MAN, null);
+        DiffResult<Person> result = DiffUtils.diffResult(person, person);
+        assertFalse(result.isDiff());
+        assertEquals(0, result.getNumberOfDiffs());
+    }
+
+    @Test
+    public void testEqualFieldsNoDiff() {
+        Person p1 = person("jack", 10, Sex.MAN, address("cn", "shanghai"));
+        Person p2 = person("jack", 10, Sex.MAN, address("cn", "shanghai"));
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertFalse(result.isDiff());
+        assertEquals(0, result.getNumberOfDiffs());
+    }
+
+    @Test
+    public void testSimpleFieldDiff() {
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        Person p2 = person("tom", 10, Sex.MAN, null);
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertTrue(result.isDiff());
+        assertEquals(1, result.getNumberOfDiffs());
+        Diff<?> diff = result.getDiffs().get(0);
+        assertEquals("name", diff.getFieldName());
+        assertEquals("jack", diff.getLeft());
+        assertEquals("tom", diff.getRight());
+    }
+
+    @Test
+    public void testDiffIgnoreAnnotation() {
+        // age 字段标有 @DiffIgnore，两边 age 不同也不应产生 diff
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        Person p2 = person("jack", 11, Sex.MAN, null);
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertFalse(result.isDiff());
+        assertEquals(0, result.getNumberOfDiffs());
+    }
+
+    @Test
+    public void testExcludeField() {
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        Person p2 = person("tom", 10, Sex.MAN, null);
+        // 注意：直接传 diffResult(p1, p2, "name") 会因 DiffUtils 的重载歧义无法编译，这里用显式数组
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2, new String[]{"name"});
+        assertEquals(0, result.getNumberOfDiffs());
+    }
+
+    @Test
+    public void testExcludeMultipleFields() {
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        p1.setMobile("17000000056");
+        p1.setEmail("wangtest1111@126.com");
+        Person p2 = person("tom", 10, Sex.MAN, null);
+        p2.setMobile("17130000056");
+        p2.setEmail("litest2211@126.com");
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2, new String[]{"name", "mobile", "email"});
+        assertEquals(0, result.getNumberOfDiffs());
+    }
+
+    @Test
+    public void testDiffAlias() {
+        Person p1 = person("jack", 10, Sex.MAN, address("tangzhen", "shanghai"));
+        Person p2 = person("jack", 10, Sex.MAN, address("tangzhen", "beijing"));
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertEquals(1, result.getNumberOfDiffs());
+        Diff<?> diff = result.getDiffs().get(0);
+        // Address.city 标有 @DiffAlias(alias = "城市")
+        assertEquals("城市", diff.getActualName());
+        assertEquals("shanghai", diff.getLeft());
+        assertEquals("beijing", diff.getRight());
+    }
+
+    @Test
+    public void testDateFormat() {
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        p1.setBirthDate(LocalDateTime.of(2026, 8, 12, 10, 30));
+        Person p2 = person("jack", 10, Sex.MAN, null);
+        p2.setBirthDate(LocalDateTime.of(2026, 8, 2, 10, 30));
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertEquals(1, result.getNumberOfDiffs());
+        Diff<?> diff = result.getDiffs().get(0);
+        assertEquals("birthDate", diff.getFieldName());
+        // birthDate 标有 @DiffFormat(pattern = "yyyy-MM-dd")
+        assertEquals("2026-08-12", diff.getFormatValue(diff.getLeft()));
+        assertEquals("2026-08-02", diff.getFormatValue(diff.getRight()));
+    }
+
+    @Test
+    public void testCustomEnumComparator() {
+        // sex 字段标有 @DiffCompare(using = SelfEnumComparator.class)
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        Person p2 = person("jack", 10, Sex.WOMAN, null);
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertEquals(1, result.getNumberOfDiffs());
+        assertEquals("sex", result.getDiffs().get(0).getFieldName());
+    }
+
+    @Test
+    public void testCustomEnumComparatorSameValueNoDiff() {
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        Person p2 = person("jack", 10, Sex.MAN, null);
+        assertEquals(0, DiffUtils.diffResult(p1, p2).getNumberOfDiffs());
+    }
+
+    @Test
+    public void testNestedDiffBean() {
+        Person p1 = person("jack", 10, Sex.MAN, address("tangzhen", "shanghai"));
+        Person p2 = person("jack", 10, Sex.MAN, address("daxing", "shanghai"));
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertEquals(1, result.getNumberOfDiffs());
+        assertEquals("address.country", result.getDiffs().get(0).getFieldName());
+    }
+
+    @Test
+    public void testNestedDiffBeanWithNullSide() {
+        // 一边为 null，应逐字段比较出差异
+        Person p1 = person("jack", 10, Sex.MAN, address("tangzhen", "shanghai"));
+        Person p2 = person("jack", 10, Sex.MAN, null);
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertTrue(result.isDiff());
+        assertTrue(result.getNumberOfDiffs() > 0);
+    }
+
+    @Test
+    public void testBeanCollectionCustomType() {
+        // 集合元素为自定义类型 Packet，元素内 money 使用 BigDecimalEffectiveDiffComparator
+        // 1.0 与 1.00 视为相等，应无差异
+        Packet packet1 = new Packet();
+        packet1.setName("LV");
+        packet1.setMoney(new BigDecimal("1.0"));
+        Packet packet2 = new Packet();
+        packet2.setName("LV");
+        packet2.setMoney(new BigDecimal("1.00"));
+
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        p1.setPacketList(Arrays.asList(packet1));
+        Person p2 = person("jack", 10, Sex.MAN, null);
+        p2.setPacketList(Arrays.asList(packet2));
+
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertEquals(0, result.getNumberOfDiffs());
+    }
+
+    @Test
+    public void testBeanCollectionCustomTypeDiff() {
+        Packet packet1 = new Packet();
+        packet1.setName("LV");
+        packet1.setMoney(new BigDecimal("1.0"));
+        Packet packet2 = new Packet();
+        packet2.setName("PT");
+        packet2.setMoney(new BigDecimal("1.0"));
+
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        p1.setPacketList(Arrays.asList(packet1));
+        Person p2 = person("jack", 10, Sex.MAN, null);
+        p2.setPacketList(Arrays.asList(packet2));
+
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertEquals(1, result.getNumberOfDiffs());
+        assertEquals("packetList[0].name", result.getDiffs().get(0).getFieldName());
+        assertEquals("LV", result.getDiffs().get(0).getLeft());
+        assertEquals("PT", result.getDiffs().get(0).getRight());
+    }
+
+    @Test
+    public void testBeanCollectionCustomTypeIndexAligned() {
+        // 集合长度不同时按索引对齐比较，多出的元素与 null 比较
+        Packet packet1 = new Packet();
+        packet1.setName("LV");
+        Packet packet2 = new Packet();
+        packet2.setName("PT");
+
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        p1.setPacketList(Arrays.asList(packet1, packet2));
+        Person p2 = person("jack", 10, Sex.MAN, null);
+        p2.setPacketList(Arrays.asList(packet1));
+
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertTrue(result.isDiff());
+        assertTrue(result.getDiffs().stream().anyMatch(d -> d.getFieldName().startsWith("packetList[1]")));
+    }
+
+    @Test
+    public void testBeanCollectionJdkTypeSame() {
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        p1.setFriendIdList(Arrays.asList(1, 2, 3));
+        Person p2 = person("jack", 10, Sex.MAN, null);
+        p2.setFriendIdList(Arrays.asList(1, 2, 3));
+        assertEquals(0, DiffUtils.diffResult(p1, p2).getNumberOfDiffs());
+    }
+
+    @Test
+    public void testBeanCollectionJdkTypeDiff() {
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        p1.setFriendIdList(Arrays.asList(1, 2, 3));
+        Person p2 = person("jack", 10, Sex.MAN, null);
+        p2.setFriendIdList(Arrays.asList(1, 2, 4));
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+        assertEquals(1, result.getNumberOfDiffs());
+        assertEquals("friendIdList", result.getDiffs().get(0).getFieldName());
+    }
+
+    @Test
+    public void testToStringContainsArrow() {
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        Person p2 = person("tom", 10, Sex.MAN, null);
+        String diff = DiffUtils.diff(p1, p2);
+        assertTrue(diff.contains("->"));
+        assertTrue(diff.contains("jack"));
+        assertTrue(diff.contains("tom"));
+    }
+
+    @Test
+    public void testDiffResultApi() {
+        Person p1 = person("jack", 10, Sex.MAN, null);
+        Person p2 = person("tom", 10, Sex.MAN, null);
+        DiffResult<Person> result = DiffUtils.diffResult(p1, p2);
+
+        assertSame(p1, result.getLeft());
+        assertSame(p2, result.getRight());
+        assertTrue(result.getNumberOfDiffs() > 0);
+        assertTrue(result.isDiff());
+
+        // getDiffs() 返回不可修改列表
+        List<Diff<?>> diffs = result.getDiffs();
+        assertThrows(UnsupportedOperationException.class, () -> diffs.add(null));
+
+        // 支持迭代
+        Iterator<Diff<?>> iterator = result.iterator();
+        assertTrue(iterator.hasNext());
+        assertTrue(iterator.next().getFieldName() != null);
+    }
+}