Mockito Mock Void Method Examples

Author: Pankaj Kumar

.gitignore

@@ -1,4 +1,5 @@
 target/
+test-output/
 .DS_Store
 .classpath
 .project

Mockito-Examples/src/main/java/com/journaldev/Employee.java

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+package com.journaldev;
+
+public class Employee {
+
+	private String name;
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		if (name == null)
+			throw new IllegalArgumentException("Employee Name can't be null");
+		this.name = name;
+	}
+
+}

Mockito-Examples/src/test/java/com/journaldev/mockito/voidmethod/JUnitMockitoVoidMethod.java

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+package com.journaldev.mockito.voidmethod;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import org.junit.jupiter.api.Test;
+
+import com.journaldev.Employee;
+
+class JUnitMockitoVoidMethod {
+
+	@Test
+	void test_mockito_void() {
+		Employee emp = mock(Employee.class);
+
+		doThrow(IllegalArgumentException.class).when(emp).setName(null);
+
+		doAnswer((i) -> {
+			System.out.println("Employee setName Argument = " + i.getArgument(0));
+			assertTrue("Pankaj".equals(i.getArgument(0)));
+			return null;
+		}).when(emp).setName(anyString());
+
+		when(emp.getName()).thenReturn("Pankaj");
+
+		assertThrows(IllegalArgumentException.class, () -> emp.setName(null));
+
+		emp.setName("Pankaj");
+		assertEquals("Pankaj", emp.getName());
+	}
+
+}

Mockito-Examples/src/test/java/com/journaldev/mockito/voidmethod/TestNGMockitoVoidMethod.java

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+package com.journaldev.mockito.voidmethod;
+
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertThrows;
+import static org.testng.Assert.assertTrue;
+
+import org.testng.annotations.Test;
+
+import com.journaldev.Employee;
+
+class TestNGMockitoVoidMethod {
+
+	@Test
+	void test_mockito_void() {
+		Employee emp = mock(Employee.class);
+
+		doThrow(IllegalArgumentException.class).when(emp).setName(null);
+
+		doAnswer((i) -> {
+			System.out.println("Employee setName Argument = " + i.getArgument(0));
+			assertTrue("Pankaj".equals(i.getArgument(0)));
+			return null;
+		}).when(emp).setName(anyString());
+
+		when(emp.getName()).thenReturn("Pankaj");
+
+		assertThrows(IllegalArgumentException.class, () -> emp.setName(null));
+
+		emp.setName("Pankaj");
+		assertEquals("Pankaj", emp.getName());
+	}
+
+}