refactor: move integration tests to dedicated folder

- Create integration test package
- Move NullEqualsEmptyArrayMatcher integration tests to new class
- Add tests for nested structures (deeply nested, inside arrays, multiple fields)
- Keep only unit tests in NullEqualsEmptyArrayMatcherTest

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: deblockt

src/test/java/com/deblock/jsondiff/integration/NullEqualsEmptyArrayMatcherIntegrationTest.java

@@ -0,0 +1,87 @@
+package com.deblock.jsondiff.integration;
+
+import com.deblock.jsondiff.DiffGenerator;
+import com.deblock.jsondiff.matcher.*;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class NullEqualsEmptyArrayMatcherIntegrationTest {
+
+    private final CompositeJsonMatcher jsonMatcher = new CompositeJsonMatcher(
+        new NullEqualsEmptyArrayMatcher(),
+        new LenientJsonArrayPartialMatcher(),
+        new LenientJsonObjectPartialMatcher(),
+        new StrictPrimitivePartialMatcher()
+    );
+
+    @Test
+    public void shouldMatchNullAndEmptyArray() {
+        final var expected = "{\"items\": null}";
+        final var received = "{\"items\": []}";
+
+        final var diff = DiffGenerator.diff(expected, received, jsonMatcher);
+
+        assertEquals(100.0, diff.similarityRate());
+    }
+
+    @Test
+    public void shouldMatchEmptyArrayAndNull() {
+        final var expected = "{\"items\": []}";
+        final var received = "{\"items\": null}";
+
+        final var diff = DiffGenerator.diff(expected, received, jsonMatcher);
+
+        assertEquals(100.0, diff.similarityRate());
+    }
+
+    @Test
+    public void shouldNotMatchNullAndNonEmptyArray() {
+        final var expected = "{\"items\": null}";
+        final var received = "{\"items\": [1, 2, 3]}";
+
+        final var diff = DiffGenerator.diff(expected, received, jsonMatcher);
+
+        assertTrue(diff.similarityRate() < 100.0);
+    }
+
+    @Test
+    public void shouldMatchNullAndEmptyArrayInNestedObject() {
+        final var expected = "{\"data\": {\"items\": null, \"name\": \"test\"}}";
+        final var received = "{\"data\": {\"items\": [], \"name\": \"test\"}}";
+
+        final var diff = DiffGenerator.diff(expected, received, jsonMatcher);
+
+        assertEquals(100.0, diff.similarityRate());
+    }
+
+    @Test
+    public void shouldMatchNullAndEmptyArrayInDeeplyNestedStructure() {
+        final var expected = "{\"level1\": {\"level2\": {\"level3\": {\"items\": null}}}}";
+        final var received = "{\"level1\": {\"level2\": {\"level3\": {\"items\": []}}}}";
+
+        final var diff = DiffGenerator.diff(expected, received, jsonMatcher);
+
+        assertEquals(100.0, diff.similarityRate());
+    }
+
+    @Test
+    public void shouldMatchNullAndEmptyArrayInsideArray() {
+        final var expected = "{\"data\": [{\"items\": null}, {\"items\": [1]}]}";
+        final var received = "{\"data\": [{\"items\": []}, {\"items\": [1]}]}";
+
+        final var diff = DiffGenerator.diff(expected, received, jsonMatcher);
+
+        assertEquals(100.0, diff.similarityRate());
+    }
+
+    @Test
+    public void shouldMatchMultipleNullAndEmptyArrayFields() {
+        final var expected = "{\"array1\": null, \"array2\": null, \"value\": \"test\"}";
+        final var received = "{\"array1\": [], \"array2\": [], \"value\": \"test\"}";
+
+        final var diff = DiffGenerator.diff(expected, received, jsonMatcher);
+
+        assertEquals(100.0, diff.similarityRate());
+    }
+}

src/test/java/com/deblock/jsondiff/matcher/NullEqualsEmptyArrayMatcherTest.java

@@ -101,54 +101,4 @@ public void jsonDiff_shouldReturnUnMatch_whenNonEmptyArrayVsNull() {
         assertEquals(0.0, result.similarityRate());
     }
 
-    @Test
-    public void integrationTest_shouldMatchNullAndEmptyArrayInJson() {
-        final var expected = "{\"items\": null}";
-        final var received = "{\"items\": []}";
-
-        final var jsonMatcher = new CompositeJsonMatcher(
-            new NullEqualsEmptyArrayMatcher(),
-            new LenientJsonArrayPartialMatcher(),
-            new LenientJsonObjectPartialMatcher(),
-            new StrictPrimitivePartialMatcher()
-        );
-
-        final var diff = com.deblock.jsondiff.DiffGenerator.diff(expected, received, jsonMatcher);
-
-        assertEquals(100.0, diff.similarityRate());
-    }
-
-    @Test
-    public void integrationTest_shouldMatchEmptyArrayAndNullInJson() {
-        final var expected = "{\"items\": []}";
-        final var received = "{\"items\": null}";
-
-        final var jsonMatcher = new CompositeJsonMatcher(
-            new NullEqualsEmptyArrayMatcher(),
-            new LenientJsonArrayPartialMatcher(),
-            new LenientJsonObjectPartialMatcher(),
-            new StrictPrimitivePartialMatcher()
-        );
-
-        final var diff = com.deblock.jsondiff.DiffGenerator.diff(expected, received, jsonMatcher);
-
-        assertEquals(100.0, diff.similarityRate());
-    }
-
-    @Test
-    public void integrationTest_shouldNotMatchNullAndNonEmptyArray() {
-        final var expected = "{\"items\": null}";
-        final var received = "{\"items\": [1, 2, 3]}";
-
-        final var jsonMatcher = new CompositeJsonMatcher(
-            new NullEqualsEmptyArrayMatcher(),
-            new LenientJsonArrayPartialMatcher(),
-            new LenientJsonObjectPartialMatcher(),
-            new StrictPrimitivePartialMatcher()
-        );
-
-        final var diff = com.deblock.jsondiff.DiffGenerator.diff(expected, received, jsonMatcher);
-
-        assertTrue(diff.similarityRate() < 100.0);
-    }
 }