Initial commit for BAEL-1515

testing-modules/testing/pom.xml

@@ -154,6 +154,17 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <groupId>org.assertj</groupId>
+                <artifactId>assertj-assertions-generator-maven-plugin</artifactId>
+                <version>${assertj-generator.version}</version>
+                <configuration>
+                    <classes>
+                        <param>com.baeldung.testing.assertj.custom.Person</param>
+                        <param>com.baeldung.testing.assertj.custom.Car</param>
+                    </classes>
+                </configuration>
+            </plugin>
         </plugins>
     </build>
 
@@ -164,6 +175,7 @@
         <guava.version>21.0</guava.version>
         <assertj-guava.version>3.1.0</assertj-guava.version>
         <assertj-core.version>3.6.1</assertj-core.version>
+        <assertj-generator.version>2.1.0</assertj-generator.version>
         <truth.version>0.32</truth.version>
         <jUnitParams.version>1.1.0</jUnitParams.version>
         <jgotesting.version>0.12</jgotesting.version>

testing-modules/testing/src/main/java/com/baeldung/testing/assertj/custom/Assertions.java

@@ -0,0 +1,11 @@
+package com.baeldung.testing.assertj.custom;
+
+public class Assertions {
+    public static PersonAssert assertThat(Person actual) {
+        return new PersonAssert(actual);
+    }
+
+    public static CarAssert assertThat(Car actual) {
+        return new CarAssert(actual);
+    }
+}

testing-modules/testing/src/main/java/com/baeldung/testing/assertj/custom/Car.java

@@ -0,0 +1,22 @@
+package com.baeldung.testing.assertj.custom;
+
+public class Car {
+    private String type;
+    private Person owner;
+
+    public Car(String type) {
+        this.type = type;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    public Person getOwner() {
+        return owner;
+    }
+
+    public void setOwner(Person owner) {
+        this.owner = owner;
+    }
+}

testing-modules/testing/src/main/java/com/baeldung/testing/assertj/custom/CarAssert.java

@@ -0,0 +1,30 @@
+package com.baeldung.testing.assertj.custom;
+
+import org.assertj.core.api.AbstractAssert;
+
+public class CarAssert extends AbstractAssert<CarAssert, Car> {
+
+    public CarAssert(Car actual) {
+        super(actual, CarAssert.class);
+    }
+
+    public static CarAssert assertThat(Car actual) {
+        return new CarAssert(actual);
+    }
+
+    public CarAssert hasType(String type) {
+        isNotNull();
+        if (!actual.getType().equals(type)) {
+            failWithMessage("Expected type %s but was %s", type, actual.getType());
+        }
+        return this;
+    }
+
+    public CarAssert isUsed() {
+        isNotNull();
+        if (actual.getOwner() == null) {
+            failWithMessage("Expected old but was new");
+        }
+        return this;
+    }
+}

testing-modules/testing/src/main/java/com/baeldung/testing/assertj/custom/Person.java

@@ -0,0 +1,32 @@
+package com.baeldung.testing.assertj.custom;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Person {
+    private String fullName;
+    private int age;
+    private List<String> nicknames;
+
+    public Person(String fullName, int age) {
+        this.fullName = fullName;
+        this.age = age;
+        this.nicknames = new ArrayList<>();
+    }
+
+    public void addNickname(String nickname) {
+        nicknames.add(nickname);
+    }
+
+    public String getFullName() {
+        return fullName;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public List<String> getNicknames() {
+        return nicknames;
+    }
+}

testing-modules/testing/src/main/java/com/baeldung/testing/assertj/custom/PersonAssert.java

@@ -0,0 +1,38 @@
+package com.baeldung.testing.assertj.custom;
+
+import org.assertj.core.api.AbstractAssert;
+
+public class PersonAssert extends AbstractAssert<PersonAssert, Person> {
+
+    public PersonAssert(Person actual) {
+        super(actual, PersonAssert.class);
+    }
+
+    public static PersonAssert assertThat(Person actual) {
+        return new PersonAssert(actual);
+    }
+
+    public PersonAssert hasFullName(String fullName) {
+        isNotNull();
+        if (!actual.getFullName().equals(fullName)) {
+            failWithMessage("Expected full name %s but was %s", fullName, actual.getFullName());
+        }
+        return this;
+    }
+
+    public PersonAssert isAdult() {
+        isNotNull();
+        if (actual.getAge() < 18) {
+            failWithMessage("Expected adult but was juvenile");
+        }
+        return this;
+    }
+
+    public PersonAssert hasNickname(String nickName) {
+        isNotNull();
+        if (!actual.getNicknames().contains(nickName)) {
+            failWithMessage("Expected nickname %s but did not have", nickName);
+        }
+        return this;
+    }
+}

testing-modules/testing/src/test/java/com/baeldung/testing/assertj/custom/AssertJCarAssertUnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.testing.assertj.custom;
+
+import static com.baeldung.testing.assertj.custom.CarAssert.assertThat;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+public class AssertJCarAssertUnitTest {
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    @Test
+    public void whenCarTypeDoesNotMatch_thenIncorrect() {
+        thrown.expect(AssertionError.class);
+        thrown.expectMessage("Expected type SUV but was Sedan");
+        Car car = new Car("Sedan");
+        assertThat(car).hasType("SUV");
+    }
+}

testing-modules/testing/src/test/java/com/baeldung/testing/assertj/custom/AssertJCustomAssertionsUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.testing.assertj.custom;
+
+import static com.baeldung.testing.assertj.custom.Assertions.assertThat;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+public class AssertJCustomAssertionsUnitTest {
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+    
+    @Test
+    public void whenPersonDoesNotHaveAMatchingNickname_thenIncorrect() {
+        thrown.expect(AssertionError.class);
+        thrown.expectMessage("Expected nickname John but did not have");
+        Person person = new Person("John Doe", 20);
+        person.addNickname("Nick");
+        assertThat(person).hasNickname("John");
+    }
+
+    @Test
+    public void whenCarIsUsed_thenCorrect() {
+        Person person = new Person("Jane Roe", 16);
+        Car car = new Car("SUV");
+        car.setOwner(person);
+        assertThat(car).isUsed();
+    }
+}

testing-modules/testing/src/test/java/com/baeldung/testing/assertj/custom/AssertJPersonAssertUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.testing.assertj.custom;
+
+import static com.baeldung.testing.assertj.custom.PersonAssert.assertThat;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+public class AssertJPersonAssertUnitTest {
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    @Test
+    public void whenPersonNameMatches_thenCorrect() {
+        Person person = new Person("John Doe", 20);
+        assertThat(person).hasFullName("John Doe");
+    }
+
+    @Test
+    public void whenPersonAgeLessThanEighteen_thenNotAdult() {
+        thrown.expect(AssertionError.class);
+        thrown.expectMessage("Expected adult but was juvenile");
+        Person person = new Person("Jane Roe", 16);
+        assertThat(person).isAdult();
+    }
+}