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How to run test methods in specific order in JUnit4?

I want to execute test methods which are annotated by @Test in specific order.

For example:

public class MyTest {
    @Test public void test1(){}
    @Test public void test2(){}
}

I want to ensure to run test1() before test2() each time I run MyTest, but I couldn't find annotation like @Test(order=xx).

I think it's quite important feature for JUnit, if author of JUnit doesn't want the order feature, why?


Source: (StackOverflow)

Maven does not find JUnit tests to run

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] ------------------------------------------------------------------------

Source: (StackOverflow)

differences between 2 JUnit Assert classes

The JUnit framework contains 2 Assert classes (in different packages, obviously) and the methods on each appear to be very similar. Can anybody explain why this is?

The classes I'm referring to are: junit.framework.Assert and org.junit.Assert.


Source: (StackOverflow)

How to test a class that has private methods, fields or inner classes

How do I use JUnit to test a class that has internal private methods, fields or nested classes? It seems bad to change the access modifier for a method just to be able to run a test.


Source: (StackOverflow)

How do you assert that a certain exception is thrown in JUnit 4 tests?

How can I use JUnit4 idiomatically to test that some code throws an exception?

While I can certainly do something like this:

@Test
public void testFooThrowsIndexOutOfBoundsException() {
  boolean thrown = false;

  try {
    foo.doStuff();
  } catch (IndexOutOfBoundsException e) {
    thrown = true;
  }

  assertTrue(thrown);
}

I recall that there is an annotation or an Assert.xyz or something that is far less kludgy and far more in-the-spirit of JUnit for these sorts of situations.


Source: (StackOverflow)

Why doesn't JUnit provide assertNotEquals methods?

Does anybody know why JUnit 4 provides assertEquals(foo,bar) but not assertNotEqual(foo,bar) methods?

It provides assertNotSame (corresponding to assertSame) and assertFalse (corresponding to assertTrue), so it seems strange that they didn't bother including assertNotEqual.

By the way, I know that JUnit-addons provides the methods I'm looking for. I'm just asking out of curiosity.


Source: (StackOverflow)

When do Java generics require instead of and is there any downside of switching?

Given the following example (using JUnit with Hamcrest matchers)

    Map<String, Class<? extends Serializable>> expected = null;
    Map<String, Class<java.util.Date>> result = null;
    assertThat(result, is(expected));

This does not compile with the JUnit AssertThat method signature of:

public static <T> void assertThat(T actual, Matcher<T> matcher)

The compiler error message is:

Error:Error:line (102)cannot find symbol method
assertThat(java.util.Map<java.lang.String,java.lang.Class<java.util.Date>>,
org.hamcrest.Matcher<java.util.Map<java.lang.String,java.lang.Class
    <? extends java.io.Serializable>>>)

However, if I change the assertThat method signature to:

public static <T> void assertThat(T result, Matcher<? extends T> matcher)

Then the compilation works.

So three questions:

  1. Why exactly doesn't the current version compile? Although I vaguely understand the covariance issues here, I certainly couldn't explain it if I had to.
  2. Is there any downside in changing the assertThat method to Matcher<? extends T>? Are there other cases that would break if you did that?
  3. Is there any point to the genericizing of the assertThat method in JUnit? The Matcher class doesn't seem to require it, since JUnit calls the matches method, which is not typed with any generic, and just looks like an attempt to force a type safety which doesn't do anything, as the Matcher will just not in fact match, and the test will fail regardless. No unsafe operations involved (or so it seems).

For reference, here is the JUnit implementation of assertThat:

public static <T> void assertThat(T actual, Matcher<T> matcher) {
	assertThat("", actual, matcher);
}

public static <T> void assertThat(String reason, T actual,
		Matcher<T> matcher) {
	if (!matcher.matches(actual)) {
		Description description= new StringDescription();
		description.appendText(reason);
		description.appendText("\nExpected: ");
		matcher.describeTo(description);
		description.appendText("\n     got: ").appendValue(actual)
				.appendText("\n");
		throw new java.lang.AssertionError(description.toString());
	}
}

Source: (StackOverflow)

JUnit confusion: use 'extend Testcase' or '@Test'?

I've found the proper use (or at least the documentation) of JUnit very confusing. This question serves both as a future reference and as a real question.

If I've understood correctly, there are two main approaches to create and run a JUnit test:

Approach A (JUnit 3-style): create a class that extends TestCase, and start test methods with the word test. When running the class as a JUnit Test (in Eclipse), all methods starting with the word test are automatically run.

import junit.framework.TestCase;
public class DummyTestA extends TestCase {

    public void testSum() {
        int a = 5;
        int b = 10;
        int result = a + b;
        assertEquals(15, result);
    }
}

Approach B (JUnit 4-style): create a 'normal' class and prepend a @Test annotation to the method. Note that you do NOT have to start the method with the word test.

import org.junit.*;
import static org.junit.Assert.*;

public class DummyTestB {

    @Test
    public void Sum() {
        int a = 5;
        int b = 10;
        int result = a + b;
        assertEquals(15, result);
    }
}

Mixing the two seems not to be a good idea, see e.g. this stackoverflow question:

Now, my questions(s):

  1. What is the preferred approach, or when would you use one instead of the other?
  2. Approach B allows for testing for exceptions by extending the @Test annotation like in @Test(expected = ArithmeticException.class). But how do you test for exceptions when using approach A?
  3. When using approach A, you can group a number of test classes in a test suite like this:

    TestSuite suite = new TestSuite("All tests");
    suite.addTestSuite(DummyTestA.class);
    suite.addTestSuite(DummyTestAbis.class);

    But this can't be used with approach B (since each testclass should subclass TestCase). What is the proper way to group tests for approach B?

Edit: I've added the JUnit versions to both approaches


Source: (StackOverflow)

Why must jUnit's fixtureSetup be static?

I marked a method with jUnit's @BeforeClass annotation, and got this exception saying it must be static. What's the rationale? This forces all my init to be on static fields, for no good reason as far as I see.

In .Net (NUnit), this is not the case.

Edit - the fact that a method annotated with @BeforeClass runs only once has nothing to do with it being a static method - one can have a non-static method run only once (as in NUnit).


Source: (StackOverflow)

Difference between setUp() and setUpBeforeClass()

When unit testing with JUnit, there are two similar methods, setUp() and setUpBeforeClass(). What is the difference between these methods? Also, what is the difference between tearDown() and tearDownAfterClass()?

Here are the signatures:

@BeforeClass
public static void setUpBeforeClass() throws Exception {
}

@AfterClass
public static void tearDownAfterClass() throws Exception {
}

@Before
public void setUp() throws Exception {
}

@After
public void tearDown() throws Exception {
}

Source: (StackOverflow)

Compare two JSON objects in Java

I'm looking for a JSON paring library that supports comparing two JSON objects ignoring child order, specifically for unit testing JSON returning from a web service against an expected value.

Do any of the major JSON libraries support this? the org.json simply does a reference comparison.


Source: (StackOverflow)

Junit: splitting integration test and Unit tests

I've inherited a load of Junit test, but these tests (apart from most not working) are a mixture of actual unit test and integration tests (requiring external systems, db etc).

So I'm trying to think of a way to actually separate them out, so that I can run the unit test nice and quickly and the integration tests after that.

The options are..

  1. Split them into separate directories.

  2. Move to Junit4 (from v3) and annotate the classes to separate them.

  3. Use a file naming convention to tell what a class is , i.e. AdapterATest and AdapterAIntergrationTest.

3 has the issue that Eclipse has the option to "Run all tests in the selected project/package or folder". So it would make it very hard to just run the integration tests.

2: runs the risk that developers might start writing integration tests in unit test classes and it just gets messy.

1: Seems like the neatest solution, but my gut says there must be a better solution out there.

So that is my question, how do you lot break apart integration tests and proper unit tests?


Source: (StackOverflow)

Junit vs TestNG

At work we are currently still using Junit3 to run our tests. We have been considering switching over to Junit4 for new tests being written but I have been keeping an eye on TestNG for a while now. What experiences have you all had with either Junit4 or TestNG and which seems to work better for very large numbers of tests. Having flexibility in writing tests is also important to us since our functional tests cover a wide aspect and need to be written in a variety of ways to get results.

Old tests will not be re-written as they do their job just fine. What I would like to see in new tests though is flexibility in the way the test can be written, natural assertions, grouping, and easily distributed test executions.


Source: (StackOverflow)

When to use Mockito.verify()

I write JUnit test cases for 3 purposes:

  1. To ensure that my code satisfies all of the required functionality, under all (or most of) the input combinations/values.
  2. To ensure that I can change the implementation, and rely on JUnit test cases to tell me that all my functionality is still satisfied.
  3. As a documentation of all the use cases my code handles, and act as a spec for refactoring - should the code ever need to be rewritten. (Refactor the code, and if my jUnit tests fail - you probably missed some use case).

I do not understand why or when Mockito.verify() should be used. When I see verify() being called, it is telling me that my JUnit is becoming aware of the implementation. (Thus changing my implementation would break my jUnits, even though my functionality was unaffected).

I'm looking for:

  1. What should be the guidelines for appropriate usage of Mockito.verify()

  2. Is it fundamentally correct for jUnits to be aware of, or tightly coupled to, the implementation of the class under test?


Source: (StackOverflow)

Pass a local file in to URL in Java

How do I create a new URL object using a local file, for the purpose of unit tests?

Thanks.


Source: (StackOverflow)