java - Maven does not find JUnit tests to run

Question

I have a maven program, it compiles fine. When I run mvn test it does not run any tests (under TESTs header says There are no tests to run.).

I've recreated this problem with a super simple setup which I will include below as well as the output when run with -X.

The unit tests run fine from eclipse (both with its default junit package and when I instead include the junit.jar downloaded by maven). Also mvn test-compile correctly creates the class under test-classes. I am running this on OSX 10.6.7 with Maven 3.0.2 and java 1.6.0_24.

Here is the directory structure:

/my_program/pom.xml
/my_program/src/main/java/ClassUnderTest.java
/my_program/src/test/java/ClassUnderTestTests.java

pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>my_group</groupId>
    <artifactId>my_program</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>My Program</name>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.8.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.5</source>
                    <target>1.5</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

ClassUnderTest.java:

public class ClassUnderTest {

    public int functionUnderTest(int n) {
        return n;
    }

}

ClassUnderTestTests.java:

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

public class ClassUnderTestTests {

    private ClassUnderTest o;

    @Before
    public void setUp() {
        o = new ClassUnderTest();
    }

    @Test
    public void testFunctionUnderTest_testCase1() {
        Assert.assertEquals(1, o.functionUnderTest(1));
    }

    @Test
    public void testFunctionUnderTest_testCase2() {
        Assert.assertEquals(2, o.functionUnderTest(2));
    }
}

End of mvn -X test:

[DEBUG] Configuring mojo org.apache.maven.plugins:maven-surefire-plugin:2.7.1:test from plugin realm ClassRealm[plugin>org.apache.maven.plugins:maven-surefire-plugin:2.7.1, parent: sun.misc.Launcher$AppClassLoader@5224ee]
[DEBUG] Configuring mojo 'org.apache.maven.plugins:maven-surefire-plugin:2.7.1:test' with basic configurator -->
[DEBUG]   (s) basedir = /Users/aaron/Programs/my_program
[DEBUG]   (s) childDelegation = false
[DEBUG]   (s) classesDirectory = /Users/aaron/Programs/my_program/target/classes
[DEBUG]   (s) disableXmlReport = false
[DEBUG]   (s) enableAssertions = true
[DEBUG]   (s) forkMode = once
[DEBUG]   (s) junitArtifactName = junit:junit
[DEBUG]   (s) localRepository =        id: local
      url: file:///Users/aaron/.m2/repository/
   layout: none

[DEBUG]   (f) parallelMavenExecution = false
[DEBUG]   (s) pluginArtifactMap = {org.apache.maven.plugins:maven-surefire-plugin=org.apache.maven.plugins:maven-surefire-plugin:maven-plugin:2.7.1:, org.apache.maven.surefire:surefire-booter=org.apache.maven.surefire:surefire-booter:jar:2.7.1:compile, org.apache.maven.surefire:surefire-api=org.apache.maven.surefire:surefire-api:jar:2.7.1:compile, org.apache.maven.surefire:maven-surefire-common=org.apache.maven.surefire:maven-surefire-common:jar:2.7.1:compile, org.apache.maven.shared:maven-common-artifact-filters=org.apache.maven.shared:maven-common-artifact-filters:jar:1.3:compile, org.codehaus.plexus:plexus-utils=org.codehaus.plexus:plexus-utils:jar:2.0.5:compile, junit:junit=junit:junit:jar:3.8.1:compile, org.apache.maven.reporting:maven-reporting-api=org.apache.maven.reporting:maven-reporting-api:jar:2.0.9:compile}
[DEBUG]   (s) printSummary = true
[DEBUG]   (s) project = MavenProject: my_group:my_program:1.0-SNAPSHOT @ /Users/aaron/Programs/my_program/pom.xml
[DEBUG]   (s) projectArtifactMap = {junit:junit=junit:junit:jar:4.8.1:test}
[DEBUG]   (s) redirectTestOutputToFile = false
[DEBUG]   (s) remoteRepositories = [       id: central
      url: http://repo1.maven.org/maven2
   layout: default
snapshots: [enabled => false, update => daily]
 releases: [enabled => true, update => never]
]
[DEBUG]   (s) reportFormat = brief
[DEBUG]   (s) reportsDirectory = /Users/aaron/Programs/my_program/target/surefire-reports
[DEBUG]   (s) session = org.apache.maven.execution.MavenSession@dfbb43
[DEBUG]   (s) skip = false
[DEBUG]   (s) skipTests = false
[DEBUG]   (s) testClassesDirectory = /Users/aaron/Programs/my_program/target/test-classes
[DEBUG]   (s) testFailureIgnore = false
[DEBUG]   (s) testNGArtifactName = org.testng:testng
[DEBUG]   (s) testSourceDirectory = /Users/aaron/Programs/my_program/src/test/java
[DEBUG]   (s) trimStackTrace = true
[DEBUG]   (s) useFile = true
[DEBUG]   (s) useManifestOnlyJar = true
[DEBUG]   (s) workingDirectory = /Users/aaron/Programs/my_program
[DEBUG] -- end configuration --
[INFO] Surefire report directory: /Users/aaron/Programs/my_program/target/surefire-reports
[DEBUG] Setting system property [user.dir]=[/Users/aaron/Programs/my_program]
[DEBUG] Setting system property [localRepository]=[/Users/aaron/.m2/repository]
[DEBUG] Setting system property [basedir]=[/Users/aaron/Programs/my_program]
[DEBUG] Using JVM: /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java
[DEBUG] Using manager EnhancedLocalRepositoryManager with priority 10 for /Users/aaron/.m2/repository
[DEBUG] dummy:dummy:jar:1.0 (selected for null)
[DEBUG]   org.apache.maven.surefire:surefire-booter:jar:2.7.1:compile (selected for compile)
[DEBUG]     org.apache.maven.surefire:surefire-api:jar:2.7.1:compile (selected for compile)
[DEBUG] Adding to surefire booter test classpath: /Users/aaron/.m2/repository/org/apache/maven/surefire/surefire-booter/2.7.1/surefire-booter-2.7.1.jar Scope: compile
[DEBUG] Adding to surefire booter test classpath: /Users/aaron/.m2/repository/org/apache/maven/surefire/surefire-api/2.7.1/surefire-api-2.7.1.jar Scope: compile
[DEBUG] Using manager EnhancedLocalRepositoryManager with priority 10 for /Users/aaron/.m2/repository
[DEBUG] dummy:dummy:jar:1.0 (selected for null)
[DEBUG]   org.apache.maven.surefire:surefire-junit4:jar:2.7.1:test (selected for test)
[DEBUG]     org.apache.maven.surefire:surefire-api:jar:2.7.1:test (selected for test)
[DEBUG] Adding to surefire test classpath: /Users/aaron/.m2/repository/org/apache/maven/surefire/surefire-junit4/2.7.1/surefire-junit4-2.7.1.jar Scope: test
[DEBUG] Adding to surefire test classpath: /Users/aaron/.m2/repository/org/apache/maven/surefire/surefire-api/2.7.1/surefire-api-2.7.1.jar Scope: test
[DEBUG] Test Classpath :
[DEBUG]   /Users/aaron/Programs/my_program/target/test-classes
[DEBUG]   /Users/aaron/Programs/my_program/target/classes
[DEBUG]   /Users/aaron/.m2/repository/junit/junit/4.8.1/junit-4.8.1.jar
[DEBUG] Using manager EnhancedLocalRepositoryManager with priority 10 for /Users/aaron/.m2/repository
[DEBUG] dummy:dummy:jar:1.0 (selected for null)
[DEBUG]   org.apache.maven.surefire:surefire-booter:jar:2.7.1:compile (selected for compile)
[DEBUG]     org.apache.maven.surefire:surefire-api:jar:2.7.1:compile (selected for compile)
[DEBUG] Adding to surefire booter test classpath: /Users/aaron/.m2/repository/org/apache/maven/surefire/surefire-booter/2.7.1/surefire-booter-2.7.1.jar Scope: compile
[DEBUG] Adding to surefire booter test classpath: /Users/aaron/.m2/repository/org/apache/maven/surefire/surefire-api/2.7.1/surefire-api-2.7.1.jar Scope: compile
Forking command line: /bin/sh -c cd /Users/aaron/Programs/my_program && /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java -jar /Users/aaron/Programs/my_program/target/surefire/surefirebooter6118081963679415631.jar /Users/aaron/Programs/my_program/target/surefire/surefire4887918564882595612tmp /Users/aaron/Programs/my_program/target/surefire/surefire9012255138269731406tmp

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
There are no tests to run.

Results :

Tests run: 0, Failures: 0, Errors: 0, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.089s
[INFO] Finished at: Mon May 30 12:03:09 EDT 2011
[INFO] Final Memory: 7M/62M
[INFO] ------------------------------------------------------------------------

Answer 1

By default Maven uses the following naming conventions when looking for tests to run:

• Test*
• *Test
• *Tests (has been added in Maven Surefire Plugin 2.20)
• *TestCase

If your test class doesn't follow these conventions you should rename it or configure Maven Surefire Plugin to use another pattern for test classes.