JUnit 5 Tutorial

In this tutorial, we will learn how to use Assertions.assertAll() method to group different assertions.

Overloaded Assertions.assertAll() Methods

There are six overloaded versions of assertAll static methods.

static void assertAll (String heading, Collection executables) - Asserts that all supplied executables do not throw exceptions.
static void assertAll (String heading, Stream executables) - Asserts that all supplied executables do not throw exceptions.
static void assertAll (String heading, Executable... executables) - Asserts that all supplied executables do not throw exceptions.
static void assertAll (Collection executables) - Asserts that all supplied executables do not throw exceptions.
static void assertAll (Stream executables) - Asserts that all supplied executables do not throw exceptions.
static void assertAll (Executable... executables) - Asserts that all supplied executables do not throw exceptions.

Create Student Class

In this example, we will create and test the Student class to demonstrate the usage of overloaded assertAll() methods with examples.

Let's first create a Student class with firstName and lastName fields:

public class Student {
   public String firstName;
   public String lastName;

   public Student(String firstName, String lastName) {
     this.firstName = firstName;
     this.lastName = lastName;
   }

   public String getFirstName() {
     return firstName;
   }

   public void setFirstName(String firstName) {
     this.firstName = firstName;
   }

   public String getLastName() {
     return lastName;
   }

   public void setLastName(String lastName) {
     this.lastName = lastName;
   }
}

Grouped Assertions Example

In a grouped assertion all assertions are executed, and any failures will be reported together.

Refer comments are self-descriptive.

import static org.junit.jupiter.api.Assertions.assertAll;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;

import org.junit.jupiter.api.Test;

import com.javaguides.junit5.Student;

public class AssertAllExample {
    @Test
    void groupedAssertions() {
        Student student = new Student("Ramesh", "Fadatare");

        // In a grouped assertion all assertions are executed, and any
        // failures will be reported together.
        assertAll("student", () -> assertEquals("Ramesh", student.getFirstName()),
                () -> assertEquals("Fadatare", student.getLastName()));
    }
}

Dependent Assertions Example

Within a code block, if an assertion fails the subsequent code in the same block will be skipped.

Refer comments are self-descriptive.

import static org.junit.jupiter.api.Assertions.assertAll;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;

import org.junit.jupiter.api.Test;

import com.javaguides.junit5.Student;

public class AssertAllExample {
    @Test
    void dependentAssertions() {
        // Within a code block, if an assertion fails the
        // subsequent code in the same block will be skipped.
  
        Student student = new Student("Ramesh", "Fadatare");
        assertAll("properties",
            () -> {
                String firstName = student.getFirstName();
                assertNotNull(firstName);

                // Executed only if the previous assertion is valid.
                assertAll("first name",
                    () -> assertTrue(firstName.startsWith("R")),
                    () -> assertTrue(firstName.endsWith("h"))
                );
            },
            () -> {
                // Grouped assertion, so processed independently
                // of results of first name assertions.
                String lastName = student.getLastName();
                assertNotNull(lastName);

                // Executed only if the previous assertion is valid.
                assertAll("last name",
                    () -> assertTrue(lastName.startsWith("F")),
                    () -> assertTrue(lastName.endsWith("e"))
                );
            }
        );
    }
}

Complete Program for Reference

import static org.junit.jupiter.api.Assertions.assertAll;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;

import org.junit.jupiter.api.Test;

import com.javaguides.junit5.Student;

public class AssertAllExample {
    @Test
    void groupedAssertions() {
        Student student = new Student("Ramesh", "Fadatare");

        // In a grouped assertion all assertions are executed, and any
        // failures will be reported together.
        assertAll("student", () -> assertEquals("Ramesh", student.getFirstName()),
                () -> assertEquals("Fadatare", student.getLastName()));
    }
 
    @Test
    void dependentAssertions() {
        // Within a code block, if an assertion fails the
        // subsequent code in the same block will be skipped.
  
        Student student = new Student("Ramesh", "Fadatare");
        assertAll("properties",
            () -> {
                String firstName = student.getFirstName();
                assertNotNull(firstName);

                // Executed only if the previous assertion is valid.
                assertAll("first name",
                    () -> assertTrue(firstName.startsWith("R")),
                    () -> assertTrue(firstName.endsWith("h"))
                );
            },
            () -> {
                // Grouped assertion, so processed independently
                // of results of first name assertions.
                String lastName = student.getLastName();
                assertNotNull(lastName);

                // Executed only if the previous assertion is valid.
                assertAll("last name",
                    () -> assertTrue(lastName.startsWith("F")),
                    () -> assertTrue(lastName.endsWith("e"))
                );
            }
        );
    }
}