Add support to generate random records

Resolves #397

easy-random-core/src/main/java/org/jeasy/random/EasyRandom.java

@@ -28,6 +28,7 @@
 import org.jeasy.random.util.ReflectionUtils;
 
 import java.lang.reflect.Field;
+import java.lang.reflect.RecordComponent;
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Stream;
@@ -97,7 +98,11 @@ public EasyRandom(final EasyRandomParameters easyRandomParameters) {
      * @throws ObjectCreationException when unable to create a new instance of the given type
      */
     public <T> T nextObject(final Class<T> type) {
-        return doPopulateBean(type, new RandomizationContext(type, parameters));
+        if (type.isRecord()) {
+            return createRandomRecord(type);
+        } else {
+            return doPopulateBean(type, new RandomizationContext(type, parameters));
+        }
     }
 
     /**
@@ -117,6 +122,21 @@ public <T> Stream<T> objects(final Class<T> type, final int streamSize) {
         return Stream.generate(() -> nextObject(type)).limit(streamSize);
     }
 
+    private <T> T createRandomRecord(Class<T> recordType) {
+        // generate random values for record components
+        RecordComponent[] recordComponents = recordType.getRecordComponents();
+        Object[] randomValues = new Object[recordComponents.length];
+        for (int i = 0; i < recordComponents.length; i++) {
+            randomValues[i] = this.nextObject(recordComponents[i].getType());
+        }
+        // create a random instance with random values
+        try {
+            return getCanonicalConstructor(recordType).newInstance(randomValues);
+        } catch (Exception e) {
+            throw new ObjectCreationException("Unable to create a random instance of recordType " + recordType, e);
+        }
+    }
+
     <T> T doPopulateBean(final Class<T> type, final RandomizationContext context) {
         if (exclusionPolicy.shouldBeExcluded(type, context)) {
             return null;

easy-random-core/src/main/java/org/jeasy/random/util/ReflectionUtils.java

@@ -559,6 +559,30 @@ public static Optional<Method> getReadMethod(Field field) {
         return getPublicMethod("is" + capitalizedFieldName, fieldClass);
     }
 
+    /**
+     * Get the canonical constructor of a record
+     * @param recordType the type of the record
+     * @return the canonical constructor of the record
+     * @param <T> the generic type of the record
+     */
+    public static <T> Constructor<T> getCanonicalConstructor(Class<T> recordType) {
+        RecordComponent[] recordComponents = recordType.getRecordComponents();
+        Class<?>[] componentTypes = new Class<?>[recordComponents.length];
+        for (int i = 0; i < recordComponents.length; i++) {
+            // recordComponents are ordered, see javadoc:
+            // "The components are returned in the same order that they are declared in the record header"
+            componentTypes[i] = recordComponents[i].getType();
+        }
+        try {
+            return recordType.getDeclaredConstructor(componentTypes);
+        } catch (NoSuchMethodException e) {
+            // should not happen, from Record javadoc:
+            // "A record class has the following mandated members: a public canonical constructor ,
+            // whose descriptor is the same as the record descriptor;"
+            throw new RuntimeException("Invalid record definition", e);
+        }
+    }
+
     private static String capitalize(String propertyName) {
         return propertyName.substring(0, 1).toUpperCase(ENGLISH) + propertyName.substring(1);
     }

easy-random-core/src/test/java/org/jeasy/random/RecordCreationTest.java

@@ -0,0 +1,23 @@
+package org.jeasy.random;
+
+import org.assertj.core.api.Assertions;
+import org.jeasy.random.records.Person;
+import org.junit.jupiter.api.Test;
+
+public class RecordCreationTest {
+
+    @Test
+    void testRandomRecordCreation() {
+        // given
+        EasyRandom easyRandom = new EasyRandom();
+
+        // when
+        Person person = easyRandom.nextObject(Person.class);
+
+        // then
+        Assertions.assertThat(person).isNotNull();
+        Assertions.assertThat(person.id()).isNotNull();
+        Assertions.assertThat(person.name()).isNotNull();
+    }
+
+}

easy-random-core/src/test/java/org/jeasy/random/records/Person.java

@@ -0,0 +1,3 @@
+package org.jeasy.random.records;
+
+public record Person(Long id, String name){}