add car example

Author: javajigi

src/main/java/next/fp/Car.java

@@ -0,0 +1,35 @@
+package next.fp;
+
+import java.util.Objects;
+
+public class Car {
+    private final String name;
+    private final int position;
+
+    public Car(String name, int position) {
+        this.name = name;
+        this.position = position;
+    }
+
+    public Car move(MoveStrategy moveStrategy) {
+        if (moveStrategy.isMovable()) {
+            return new Car(name, position + 1);
+        }
+        return this;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Car car = (Car) o;
+        return position == car.position &&
+                Objects.equals(name, car.name);
+    }
+
+    @Override
+    public int hashCode() {
+
+        return Objects.hash(name, position);
+    }
+}

src/main/java/next/fp/MoveStrategy.java

@@ -0,0 +1,5 @@
+package next.fp;
+
+public interface MoveStrategy {
+    boolean isMovable();
+}

src/test/java/next/fp/CarTest.java

@@ -0,0 +1,31 @@
+package next.fp;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class CarTest {
+    @Test
+    public void 이동() {
+        Car car = new Car("pobi", 0);
+        Car actual = car.move(new MoveStrategy() {
+            @Override
+            public boolean isMovable() {
+                return true;
+            }
+        });
+        assertEquals(new Car("pobi", 1), actual);
+    }
+
+    @Test
+    public void 정지() {
+        Car car = new Car("pobi", 0);
+        Car actual = car.move(new MoveStrategy() {
+            @Override
+            public boolean isMovable() {
+                return false;
+            }
+        });
+        assertEquals(new Car("pobi", 0), actual);
+    }
+}