Maven Surefire plugin in JUnit - Build an Automation Script

Run JUnit tests using Maven Surefire plugin

Preconditions (4)

Step 1: Open terminal or command prompt

Step 2: Navigate to the project root directory containing pom.xml

Step 3: Run the command 'mvn test' to execute tests

Step 4: Observe the console output for test execution results

Step 5: Verify that all JUnit tests run and pass successfully

✅ Expected Result: Maven Surefire plugin runs all JUnit tests and reports test results with no failures.

Automation Requirements - JUnit 5 with Maven Surefire plugin

Assertions Needed:

Verify that the test method executes and passes

Verify that Maven Surefire plugin reports test success in console output

Best Practices:

Use @Test annotation for test methods

Use assertions like Assertions.assertEquals or Assertions.assertTrue

Configure Maven Surefire plugin in pom.xml with correct version

Run tests via 'mvn test' command

Keep test methods independent and repeatable

Automated Solution

JUnit

package com.example;

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;

public class CalculatorTest {

    @Test
    void addition_shouldReturnCorrectSum() {
        Calculator calc = new Calculator();
        int result = calc.add(2, 3);
        assertEquals(5, result, "2 + 3 should equal 5");
    }
}

// Calculator.java
package com.example;

public class Calculator {
    public int add(int a, int b) {
        return a + b;
    }
}

// pom.xml snippet for Surefire plugin

/*
<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-surefire-plugin</artifactId>
      <version>3.0.0</version>
    </plugin>
  </plugins>
</build>
*/

This code defines a simple JUnit 5 test class CalculatorTest with one test method addition_shouldReturnCorrectSum. It tests the add method of the Calculator class.

The test uses assertEquals to check that adding 2 and 3 returns 5. This assertion ensures the test passes only if the method works correctly.

The pom.xml snippet shows how to configure the Maven Surefire plugin version 3.0.0, which runs the JUnit tests when you execute mvn test.

Running mvn test in the project directory will invoke Surefire, which finds and runs the test, then reports the result in the console.

This setup follows best practices: using JUnit 5 annotations, clear assertions, and proper Maven plugin configuration.

Common Mistakes - 4 Pitfalls

Not configuring the Maven Surefire plugin in pom.xml

Using JUnit 4 annotations with JUnit 5 dependencies

Writing test methods without assertions

{'mistake': "Running tests with 'java' command instead of 'mvn test'", 'why_bad': "Tests won't run properly because Surefire handles test discovery and execution.", 'correct_approach': "Use 'mvn test' to run tests with Maven Surefire plugin."}

Bonus Challenge

Now add data-driven testing with 3 different input pairs for the add method

Show Hint

Practice

1. What is the main purpose of the Maven Surefire plugin in a JUnit testing project?

easy

A. To deploy the application to a server

B. To compile Java source code

C. To run tests automatically during the build process

D. To package the application into a JAR file

Solution

1. Step 1: Understand the role of Maven Surefire plugin

   The Maven Surefire plugin is designed to run tests automatically during the build process, ensuring code correctness early.

2. Step 2: Differentiate from other Maven plugins

   Other plugins like compiler or deploy handle compiling or deployment, not running tests.

3. Final Answer:

   To run tests automatically during the build process -> Option C

4. Quick Check:

   Maven Surefire runs tests during build [OK]

Hint: Surefire runs tests during build, not compile or deploy [OK]

Common Mistakes:

• Confusing Surefire with compiler plugin
• Thinking Surefire packages the app
• Assuming Surefire deploys the app

2. Which XML tag correctly configures the Maven Surefire plugin in the pom.xml file?

easy

A. org.apache.maven.pluginsmaven-jar-plugin

B. org.apache.maven.pluginsmaven-compiler-plugin

C. org.junit.jupiterjunit-jupiter-engine

D. org.apache.maven.pluginsmaven-surefire-plugin

Solution

1. Step 1: Identify the correct plugin artifactId for Surefire

   The Maven Surefire plugin uses maven-surefire-plugin as its artifactId.

2. Step 2: Confirm groupId and artifactId match Surefire plugin

   The groupId is org.apache.maven.plugins, which is standard for Maven plugins.

3. Final Answer:

   <plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-surefire-plugin</artifactId></plugin> -> Option D

4. Quick Check:

   Surefire plugin artifactId = maven-surefire-plugin [OK]

Hint: Surefire plugin artifactId always contains 'surefire' [OK]

Common Mistakes:

• Using maven-compiler-plugin instead of surefire
• Confusing JUnit engine with Surefire plugin
• Using maven-jar-plugin for testing

3. Given this pom.xml snippet, what will happen when you run mvn test?

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-surefire-plugin</artifactId>
  <version>3.0.0-M7</version>
  <configuration>
    <includes>
      <include>**/*Test.java</include>
    </includes>
  </configuration>
</plugin>

medium

A. Only Java files ending with 'Test.java' will be run as tests

B. All Java files will be compiled but no tests will run

C. Tests will run only if file names start with 'Test'

D. No tests will run because version is invalid

Solution

1. Step 1: Understand the includes configuration

   The <includes> tag specifies which test files to run. Here, it includes files matching **/*Test.java.

2. Step 2: Interpret the pattern meaning

   The pattern means any Java file ending with 'Test.java' in any folder will be run as a test.

3. Final Answer:

   Only Java files ending with 'Test.java' will be run as tests -> Option A

4. Quick Check:

   Includes pattern '**/*Test.java' runs matching test files [OK]

Hint: Includes '**/*Test.java' runs files ending with 'Test.java' [OK]

Common Mistakes:

• Assuming all Java files run as tests
• Thinking files starting with 'Test' run
• Believing version 3.0.0-M7 is invalid

4. You added the Maven Surefire plugin to your pom.xml but tests are not running. Which of these is the most likely cause?

medium

A. The pom.xml file is not saved

B. The artifactId is misspelled as maven-surefire-plugn

C. The version tag is missing

D. JUnit tests are written in a different folder than src/test/java

Solution

1. Step 1: Check plugin artifactId spelling

   If the artifactId is misspelled, Maven cannot find the plugin, so tests won't run.

2. Step 2: Consider other causes

   Missing version usually defaults to latest, unsaved pom.xml is unlikely, and test folder location matters but less common cause.

3. Final Answer:

   The artifactId is misspelled as maven-surefire-plugn -> Option B

4. Quick Check:

   Misspelled artifactId stops Surefire plugin loading [OK]

Hint: Check artifactId spelling first if tests don't run [OK]

Common Mistakes:

• Ignoring typo in artifactId
• Assuming missing version always breaks build
• Not verifying test source folder

5. You want to run only tests tagged with @Fast annotation using Maven Surefire plugin. Which configuration snippet in pom.xml achieves this?

hard

A. Fast

B. Fast

C. **/*Fast.java

D. Fast*

Solution

1. Step 1: Understand Surefire's group filtering

   Surefire uses <groups> to include tests with specific JUnit categories or tags.

2. Step 2: Match the correct tag for including groups

   Using <groups>Fast</groups> runs only tests tagged with @Fast.

3. Final Answer:

   <configuration><groups>Fast</groups></configuration> -> Option A

4. Quick Check:

   Use <groups> to run tagged tests [OK]

Hint: Use <groups> tag to run tests with specific annotations [OK]

Common Mistakes:

• Using excludedGroups instead of groups
• Filtering by filename instead of annotation
• Using <test> tag incorrectly