feat BAEL-6092 Record Patterns (#13243)

* feat BAEL-6092 Record Patterns

* Update pom.xml

* Update pom.xml

* Add additional Switch Test Case

core-java-modules/core-java-19/src/main/java/com/baeldung/features/records/GPSPoint.java

@@ -0,0 +1,3 @@
+package com.baeldung.features.records;
+
+public record GPSPoint (double lat, double lng) { }

core-java-modules/core-java-19/src/main/java/com/baeldung/features/records/ILocation.java

@@ -0,0 +1,9 @@
+package com.baeldung.features.records;
+
+public sealed interface ILocation permits Location {
+    default String getName() {
+        return switch (this) {
+            case Location(var name, var ignored) -> name;
+        };
+    }
+}

core-java-modules/core-java-19/src/main/java/com/baeldung/features/records/Location.java

@@ -0,0 +1,5 @@
+package com.baeldung.features.records;
+
+public record Location(String name, GPSPoint gpsPoint) implements ILocation {
+}
+

core-java-modules/core-java-19/src/main/java/com/baeldung/features/records/LocationWrapper.java

@@ -0,0 +1,3 @@
+package com.baeldung.features.records;
+
+public record LocationWrapper<T>(T t, String description) { }

core-java-modules/core-java-19/src/test/java/com/baeldung/features/JEP405RecordPatternsUnitTest.java

@@ -0,0 +1,99 @@
+package com.baeldung.features;
+
+import com.baeldung.features.records.GPSPoint;
+import com.baeldung.features.records.Location;
+import com.baeldung.features.records.LocationWrapper;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+
+public class JEP405RecordPatternsUnitTest {
+
+    Object object = new Location("Home", new GPSPoint(1.0, 2.0));
+
+    @Test
+    void givenObject_whenTestInstanceOfAndCastIdiom_shouldMatchNewInstanceOf() {
+        // old Code
+        if (object instanceof Location) {
+            Location l = (Location) object;
+            assertThat(l).isInstanceOf(Location.class);
+        }
+        // new code
+        if (object instanceof Location l) {
+            assertThat(l).isInstanceOf(Location.class);
+        }
+    }
+
+    @Test
+    void givenObject_whenTestDestruct_shouldMatch() {
+        // when
+        if (object instanceof Location(var name, var gpsPoint)) {
+            // then
+            assertThat(name).isEqualTo("Home");
+            assertThat(gpsPoint).isInstanceOf(GPSPoint.class);
+        }
+
+        if (object instanceof Location(var name, GPSPoint(var lat, var lng))) {
+            assertThat(lat).isEqualTo(1.0);
+            assertThat(lng).isEqualTo(2.0);
+        }
+    }
+
+    @Test
+    void givenObjectIsNull_whenTestNullCheck_shouldNotMatch() {
+        Location l = null;
+        if (l instanceof Location location) {
+            assertThat(location).isNotNull();
+        }
+    }
+
+
+    @Test
+    void givenObject_whenTestGenericTypeInstanceOf_shouldMatch() {
+        LocationWrapper<Location> locationWrapper = new LocationWrapper<>(new Location("Home", new GPSPoint(1.0, 2.0)), "Description");
+        if (locationWrapper instanceof LocationWrapper<Location>(var ignored, var description)) {
+            assertThat(description).isEqualTo("Description");
+        }
+    }
+
+
+    @Test
+    void givenObject_whenTestSwitchExpressionWithTypePattern_shouldMatch() {
+        String result = switch (object) {
+            case Location l -> l.name();
+            default -> "default";
+        };
+        assertThat(result).isEqualTo("Home");
+        Double result2 = switch (object) {
+            case Location(var name, GPSPoint(var lat, var lng)) -> lat;
+            default -> 0.0;
+        };
+        assertThat(result2).isEqualTo(1.0);
+    }
+
+    @Test
+    void givenObject_whenTestGuardedSwitchExpressionWithTypePattern_shouldMatchAndGuard() {
+        String result = switch (object) {
+            case Location(var name, var ignored) when name.equals("Home") -> "Test";
+            case Location(var name, var ignored) -> name;
+            default -> "default";
+        };
+        assertThat(result).isEqualTo("Test");
+
+        String otherResult = switch (new Location("Other", new GPSPoint(1.0, 2.0))) {
+            case Location(var name, var ignored) when name.equals("Home") -> "Test";
+            case Location(var name, var ignored) -> name;
+            default -> "default";
+        };
+        assertThat(otherResult).isEqualTo("Other");
+
+        Object noLocation = new GPSPoint(1.0, 2.0);
+        String noLocationResult = switch (noLocation) {
+            case Location(var name, var ignored) when name.equals("Home") -> "Test";
+            case Location(var name, var ignored) -> name;
+            default -> "default";
+        };
+        assertThat(noLocationResult).isEqualTo("default");
+    }
+}