Writing a JUnit Rule: Description doesn't contain my annotation - java

I'm trying to write a simple JUnit Rule implementation which reruns a test case a given amount of times if not successful.
It works fine as such, but I'd like to make it configurable per method with a custom annotation I attach to the method.
Here's my rule implementation:
public class Retry implements TestRule {
private int retryCount = 10;
#Override
public Statement apply(Statement base, Description description) {
return new Statement() {
public void evaluate() throws Throwable {
RetryCount annotation = description.getAnnotation(RetryCount.class);
// Problem is here, the annotation is always null!
int retries = (annotation != null) ? annotation.retries() : retryCount;
// keep track of the last failure to include it in our failure later
AssertionError lastFailure = null;
for (int i = 0; i < retries; i++) {
try {
// call wrapped statement and return if successful
base.evaluate();
return;
} catch (AssertionError err) {
lastFailure = err;
}
}
// give meaningful message and include last failure for the
// error trace
throw new AssertionError("Gave up after " + retries + " tries", lastFailure);
}
};
}
// the annotation for method-based retries
public static #interface RetryCount {
public int retries() default 1;
}
}
In the line I commented, I don't get the annotation I attach to the method:
public class UnreliableServiceUnitTest {
private UnreliableService sut = new UnreliableService();
#Rule
public Retry retry = new Retry();
#Test
#RetryCount(retries=5) // here it is
public void worksSometimes() {
boolean worked = sut.workSometimes();
assertThat(worked, is(true));
}
}
If I debug into the Rule, the Description annotation list contains the #Test annotation but not the #RetryCount. I also tried adding a #Deprecated which will also get added.
Any idea why?
For completeness, this is the sample SUT:
public class UnreliableService {
private static Random RANDOM = new Random();
// needs at least two calls
private static int COUNTER = RANDOM.nextInt(8) + 2;
public boolean workSometimes() {
if (--COUNTER == 0) {
COUNTER = RANDOM.nextInt(8) + 2;
return true;
}
return false;
}
}

The #Test annotation is a Runtime annotation. Your RetryCount is not defined like that. It should be so you can access it during runtime. Change your code to this:
// the annotation for method-based retries
#Retention(value=RUNTIME)
public static #interface RetryCount {
public int retries() default 1;
}
Using RetentionPolicy Runtime allows you to read the annotations reflectively. See here the Javadoc

Related

How to avoid Retry adding in Test annotation?

I came across an answer on how to use Retry in Selenium web driver test. Now I have implemented Retry class under utilities and inside the test annotation given as follows #Test(retryAnalyzer = Retry.class). This is working fine now, but I would like to change this way, can I use the Retry in any other way instead of giving in test annotation as #Test(retryAnalyzer = Retry.class) ? Also I need to comment the #Test(enabled = true), Can someone please advise ?
utilities/Retryclass
public class Retry implements IRetryAnalyzer {
private int retryCount = 0;
private int maxRetryCount = 2;
public boolean retry(ITestResult result) {
if(retryCount < maxRetryCount) {
retryCount ++ ;
return true;
}
return false;
}
}
tests/RepaymentCalculatorTest
public class RepaymentCalculatorTest extends BaseTest {
Retry retryTest = new Retry();
//#Test(enabled = true)
#Test(retryAnalyzer = Retry.class)
public void loanRepaymentCalculator() throws InterruptedException {
// rest of the UI test code added here ....
}
i am using bit different way, no need to add class in #Test annotation
Lets have custom Listener for it
public class RetryFailedTestCases implements IRetryAnalyzer, IAnnotationTransformer{
public void transform(ITestAnnotation testannotation, Class testClass, Constructor testConstructor,
Method testMethod) {
testannotation.setRetryAnalyzer(RetryFailedTestCases.class);
}
int counter = 0;
int retryLimit = 1; //as per need
#Override
public boolean retry(ITestResult result) {
if(counter < retryLimit)
{
counter++;
return true;
}
return false;
}
}
Now, add this in testng.xml file
<listeners>
<listener class-name="package.RetryFailedTestCases"/>
</listeners>
this is simple and helpful when we run as suite.. alternative we can mentioned listener class on top of each class instead of testng.xml file
i am not sure why explicitly mentioned enabled = true ? even if not #Test execute right? if you dont want to execute then mention with false.

How to inject a method invocation into another method in android

I have a class with,
a field called something,
a setter method called setSomething, and,
a method called onChange which should be called every time something is changed.
I want to be able to freely add more fields and have the same behavior for all of them.
I don't want to manually call onChange because,
A lot of boilerplate,
Code will be written in Kotlin so I don't want to write setter functions at all.
The ideal solution I've been able to think of has been to somehow inject the onChange call right before the return for each setter method in compile time.
I've looked at annotation processing, but apparently classes aren't actually compiled at that stage, so I'd have to generate the entire class all over again? I don't exactly understand this.
The other option seems to be writing a gradle plugin that will find the relevant class(es) and modify their bytecode.
I've actually started work on this as a pure Java project (gradle plugin is semi-done) and have been able to find the classes and inject the method call. Can't seem to successfully write the results to a class file though.
Here's what I have (using BCEL):
public class StateStoreInjector {
public static void main(String[] args) {
// Find all classes that extends StateStore
Reflections reflections = new Reflections("tr.xip.statestore");
Set<Class<? extends StateStore>> classes = reflections.getSubTypesOf(StateStore.class);
for (Class c : classes) {
try {
JavaClass clazz = Repository.lookupClass(c.getName());
JavaClass superClazz = Repository.lookupClass(StateStore.class.getName());
if (Repository.instanceOf(clazz, superClazz)) {
injectInClass(clazz, superClazz);
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
}
private static void injectInClass(JavaClass clazz, JavaClass superClazz) {
ClassGen classGen = new ClassGen(clazz);
ConstantPoolGen cp = classGen.getConstantPool();
// Find the onChange method
Method onChangeMethod = null;
for (Method m : superClazz.getMethods()) {
if (m.getName().equals("onChange")) {
onChangeMethod = m;
}
}
if (onChangeMethod == null) {
throw new RuntimeException("onChange method not found");
}
ClassGen superClassGen = new ClassGen(superClazz);
ConstantPoolGen superCp = superClassGen.getConstantPool();
// Add onChange method ref to the class ConstantPool
MethodGen onChangeMethodGen = new MethodGen(onChangeMethod, superClassGen.getClassName(), superCp);
cp.addMethodref(onChangeMethodGen);
// Loop through all methods to inject method invocations if applicable
for (Method m : clazz.getMethods()) {
// Skip methods with names shorter than 3 chars - we're looking for setters and setters would be min 4 chars
if (m.getName().length() < 3) continue;
// Check if the method actually starts with the keyword "set"
boolean isSetMethod = m.getName().substring(0, 3).toUpperCase().equals("SET");
// Get method name without the "set" keyword
String methodName = m.getName().substring(3, m.getName().length());
// Check that we actually have a field set by this setter - that this setter is "valid"
boolean fieldWithSameNameExists = false;
for (Field f : clazz.getFields()) {
if (f.getName().toUpperCase().equals(methodName.toUpperCase())) {
fieldWithSameNameExists = true;
break;
}
}
// Proceed with injection if criteria match
Method newMethod = null;
if (isSetMethod && fieldWithSameNameExists) {
newMethod = injectInMethod(m, onChangeMethodGen, classGen, cp);
}
// Injection returned. Do we have a new/modified method? Yes? Update and write class.
if (newMethod != null) {
classGen.removeMethod(m);
classGen.addMethod(newMethod);
classGen.update();
try {
String packageName = clazz.getPackageName().replace(".", "/");
String className = clazz.getClassName();
className = className.substring(className.lastIndexOf(".") + 1, className.length());
clazz.dump(packageName + "/" + className + "Edited.class");
}
catch (IOException e) {
e.printStackTrace();
}
}
}
}
private static Method injectInMethod(Method m, MethodGen onChangeMethodGen, ClassGen cg, ConstantPoolGen cp) {
MethodGen methodGen = new MethodGen(m, cg.getClassName(), cp);
InstructionList il = methodGen.getInstructionList();
println(il.toString() + "pre insert ^");
// Find the "return" instruction
Instruction returnInstruction = null;
for (Instruction i : il.getInstructions()) {
if (i.getOpcode() == 177) returnInstruction = i;
}
// If found, insert onChange invocation instruction before the return instruction
if (returnInstruction != null) {
int index = cp.lookupMethodref(onChangeMethodGen); // Find the index of the onChange method in the CP
il.insert(returnInstruction, new INVOKEVIRTUAL(index)); // Insert the new instruction
println(il.toString() + "post insert ^");
il.setPositions(); // Fix positions
println(il.toString() + "post set pos ^");
il.update();
methodGen.update();
return methodGen.getMethod();
}
return null;
}
private static void println(String message) {
System.out.println(message);
}
}
Input Java class:
public class DummyStateStore extends StateStore {
private int id = 4321;
public void setId(int id) {
this.id = id;
}
public int getId() {
return id;
}
}
Parent Store class:
public class StateStore {
public void onChange() {
// notifies all subscribers
}
}
Output (decompiled) class file:
public class DummyStateStore extends StateStore {
private int id = 4321;
public DummyStateStore() {
}
public void setId(int id) {
this.id = id;
}
public int getId() {
return this.id;
}
}
Log output:
0: aload_0[42](1)
1: iload_1[27](1)
2: putfield[181](3) 2
5: return[177](1)
pre insert ^
0: aload_0[42](1)
1: iload_1[27](1)
2: putfield[181](3) 2
-1: invokevirtual[182](3) 26
5: return[177](1)
post insert ^
0: aload_0[42](1)
1: iload_1[27](1)
2: putfield[181](3) 2
5: invokevirtual[182](3) 26
8: return[177](1)
post set pos ^
(I checked the index 26 by debugging the code and it is the correct index in the CP)
Now, the questions are:
Why can't the invocation be seen in the decompiled code but it seems to be added to the instructions list? What am I missing?
Where would I be exporting the modified class files in an android build for them to be included in the final apk?
You're trying to use reflection, but there should be no need to do so with Kotlin as you can create higher order functions (functions that take functions as inputs).
You could do something like:
class ChangeableType<T>(private var value: T, private val onChange: () -> Unit) {
fun set(value: T) {
this.value = value
this.onChange.invoke()
}
}
class MyRandomClass() {
val something = ChangeableType(0, { System.print("Something new value: $value") })
val anotherThing = ChangeableType("String", { System.print("Another thing new value: $value") })
}
class ConsumingClass {
val myRandomClass = MyRandomClass()
fun update() {
myRandomClass.apply {
something.set(1)
anotherThing.set("Hello World")
}
}
}

How to create own annotation for junit that will skip test if concrete exception was thrown during execution?

My application have several execution modes, and in 1 mode it is normal that some of my tests will throw a concrete exception. I need to annotate this methods with something like #SkipOnFail that will set method as skipped if exception was thrown.
thanks in advance!
#Edit(for my question to be more clear)
#Test(expected=ConcreteException.class)
does not work for me because i need my tests to pass even if ConcreteException.class was not thrown(expected tag in junit will mark my test as failed if this exception won't be thrown), and to be skipped otherwise. In all other cases it should work as always.
#Solution that worked for me(junit v4.7) thx to #axtavt
#Rule
public MethodRule skipRule = new MethodRule() {
public Statement apply(final Statement base, FrameworkMethod method, Object target) {
if(method.getAnnotation(SkipOnFail.class) == null) return base;
return new Statement() {
#Override
public void evaluate() throws Throwable {
try{
base.evaluate();
} catch (ConcreteException e) {
Assume.assumeTrue(false);
}
}
};
}
};
#Thx
I don't think that such a feature is available out of the box, but it should be pretty easy to implement with custom TestRule and Assume, something like this:
#Rule
public TestRule skipRule = new TestRule() {
public Statement apply(final Statement base, Description desc) {
if (desc.getAnnotation(SkipOnFail.class) == null) return base;
return new Statement() {
public void evaluate() throws Throwable {
try {
base.evaluate();
} catch (MyExceptoion ex) {
Assume.assumeTrue(false);
}
}
};
}
};
What about using JUnit Extensions?
The following example is taken from their Tutorial.
It provides aditional annotations for Prerequisites (#Prerequisite): Ignore tests based on conditions.
The required approach would be to check this during running tests. So you can simply add a #Prerequisite(requires="") annotation.
public class TestFillDatabase {
#Prerequisite(requires = "databaseIsAvailable")
#Test public void fillData() {
// ...
}
public boolean databaseIsAvailable() {
boolean isAvailable = ...;
return isAvailable;
}
}
public class TestFillDatabase {
#Prerequisite(requires = "databaseIsAvailable")
#Test public void fillData() {
// ...
}
public boolean databaseIsAvailable() {
boolean isAvailable = ...;
return isAvailable ;
}
}
This specified methods with #Prerequisite(requires = "databaseIsAvailable") must be a public method, returning a boolean or Boolean value.
If these methods will be consolidated in helper classes, you can also specify static methods within a class to be called using #Prerequisite(requires = "databaseIsAvailable", callee="DBHelper").
public class TestFillDatabase {
#Prerequisite(requires = "databaseIsAvailable", callee="DBHelper")
#Test public void fillData() {
// ...
}
}
public class DBHelper {
public static boolean databaseIsAvailable() {
boolean isAvailable = ...;
return isAvailable ;
}
}
Also using the Assume class (since jUnit 4.4), you can use assumeNoException():
try{
base.evaluate();
} catch (ConcreteException e) {
Assume.assumeNoException("Concrete exception: skipping test", e);
}
I searched for the docs about JUnit and it appears that from version 4.9 they have introduced what they call test rules (see TestRule). You may start from this.
The ExpectedException class marked as #Rule could be of some help in order to check for exceptions thrown but not mandatory for the test to pass.
For more advanced usage I cannot say for the moment as I've just discovered it.

How to display a name/label for each Parameterized Junit test in Eclipse [duplicate]

Is there a way to set my own custom test case names when using parameterized tests in JUnit4?
I'd like to change the default — [Test class].runTest[n] — to something meaningful.
This feature has made it into JUnit 4.11.
To use change the name of parameterized tests, you say:
#Parameters(name="namestring")
namestring is a string, which can have the following special placeholders:
{index} - the index of this set of arguments. The default namestring is {index}.
{0} - the first parameter value from this invocation of the test.
{1} - the second parameter value
and so on
The final name of the test will be the name of the test method, followed by the namestring in brackets, as shown below.
For example (adapted from the unit test for the Parameterized annotation):
#RunWith(Parameterized.class)
static public class FibonacciTest {
#Parameters( name = "{index}: fib({0})={1}" )
public static Iterable<Object[]> data() {
return Arrays.asList(new Object[][] { { 0, 0 }, { 1, 1 }, { 2, 1 },
{ 3, 2 }, { 4, 3 }, { 5, 5 }, { 6, 8 } });
}
private final int fInput;
private final int fExpected;
public FibonacciTest(int input, int expected) {
fInput= input;
fExpected= expected;
}
#Test
public void testFib() {
assertEquals(fExpected, fib(fInput));
}
private int fib(int x) {
// TODO: actually calculate Fibonacci numbers
return 0;
}
}
will give names like testFib[1: fib(1)=1] and testFib[4: fib(4)=3]. (The testFib part of the name is the method name of the #Test).
Looking at JUnit 4.5, its runner clearly doesn't support that, as that logic is buried inside a private class inside the Parameterized class. You could not use the JUnit Parameterized runner, and create your own instead which would understand the concept of names (which leads to the question of how you might set a name ...).
From a JUnit perspective, it would be nice if instead of (or in addition to) just passing an increment, they would pass the comma delimited arguments. TestNG does this. If the feature is important to you, you can comment on the yahoo mailing list referenced at www.junit.org.
I recently came across the same problem when using JUnit 4.3.1. I implemented a new class which extends Parameterized called LabelledParameterized. It has been tested using JUnit 4.3.1, 4.4 and 4.5. It reconstructs the Description instance using the String representation of the first argument of each parameter array from the #Parameters method. You can see the code for this at:
http://code.google.com/p/migen/source/browse/trunk/java/src/.../LabelledParameterized.java?r=3789
and an example of its use at:
http://code.google.com/p/migen/source/browse/trunk/java/src/.../ServerBuilderTest.java?r=3789
The test description formats nicely in Eclipse which is what I wanted since this makes failed tests a lot easier to find! I will probably further refine and document the classes over the next few days/weeks. Drop the '?' part of the URLs if you want the bleeding edge. :-)
To use it, all you have to do is copy that class (GPL v3), and change #RunWith(Parameterized.class) to #RunWith(LabelledParameterized.class) assuming the first element of your parameter list is a sensible label.
I don't know if any later releases of JUnit address this issue but even if they did, I can't update JUnit since all my co-developers would have to update too and we have higher priorities than re-tooling. Hence the work in the class to be compilable by multiple versions of JUnit.
Note: there is some reflection jiggery-pokery so that it runs across the different JUnit versions as listed above. The version specifically for JUnit 4.3.1 can be found here and, for JUnit 4.4 and 4.5, here.
With Parameterized as a model, I wrote my own custom test runner / suite -- only took about half an hour. It's slightly different from darrenp's LabelledParameterized in that it lets you specify a name explicitly rather than relying on the first parameter's toString().
It also doesn't use arrays because I hate arrays. :)
public class PolySuite extends Suite {
// //////////////////////////////
// Public helper interfaces
/**
* Annotation for a method which returns a {#link Configuration}
* to be injected into the test class constructor
*/
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.METHOD)
public static #interface Config {
}
public static interface Configuration {
int size();
Object getTestValue(int index);
String getTestName(int index);
}
// //////////////////////////////
// Fields
private final List<Runner> runners;
// //////////////////////////////
// Constructor
/**
* Only called reflectively. Do not use programmatically.
* #param c the test class
* #throws Throwable if something bad happens
*/
public PolySuite(Class<?> c) throws Throwable {
super(c, Collections.<Runner>emptyList());
TestClass testClass = getTestClass();
Class<?> jTestClass = testClass.getJavaClass();
Configuration configuration = getConfiguration(testClass);
List<Runner> runners = new ArrayList<Runner>();
for (int i = 0, size = configuration.size(); i < size; i++) {
SingleRunner runner = new SingleRunner(jTestClass, configuration.getTestValue(i), configuration.getTestName(i));
runners.add(runner);
}
this.runners = runners;
}
// //////////////////////////////
// Overrides
#Override
protected List<Runner> getChildren() {
return runners;
}
// //////////////////////////////
// Private
private Configuration getConfiguration(TestClass testClass) throws Throwable {
return (Configuration) getConfigMethod(testClass).invokeExplosively(null);
}
private FrameworkMethod getConfigMethod(TestClass testClass) {
List<FrameworkMethod> methods = testClass.getAnnotatedMethods(Config.class);
if (methods.isEmpty()) {
throw new IllegalStateException("#" + Config.class.getSimpleName() + " method not found");
}
if (methods.size() > 1) {
throw new IllegalStateException("Too many #" + Config.class.getSimpleName() + " methods");
}
FrameworkMethod method = methods.get(0);
int modifiers = method.getMethod().getModifiers();
if (!(Modifier.isStatic(modifiers) && Modifier.isPublic(modifiers))) {
throw new IllegalStateException("#" + Config.class.getSimpleName() + " method \"" + method.getName() + "\" must be public static");
}
return method;
}
// //////////////////////////////
// Helper classes
private static class SingleRunner extends BlockJUnit4ClassRunner {
private final Object testVal;
private final String testName;
SingleRunner(Class<?> testClass, Object testVal, String testName) throws InitializationError {
super(testClass);
this.testVal = testVal;
this.testName = testName;
}
#Override
protected Object createTest() throws Exception {
return getTestClass().getOnlyConstructor().newInstance(testVal);
}
#Override
protected String getName() {
return testName;
}
#Override
protected String testName(FrameworkMethod method) {
return testName + ": " + method.getName();
}
#Override
protected void validateConstructor(List<Throwable> errors) {
validateOnlyOneConstructor(errors);
}
#Override
protected Statement classBlock(RunNotifier notifier) {
return childrenInvoker(notifier);
}
}
}
And an example:
#RunWith(PolySuite.class)
public class PolySuiteExample {
// //////////////////////////////
// Fixture
#Config
public static Configuration getConfig() {
return new Configuration() {
#Override
public int size() {
return 10;
}
#Override
public Integer getTestValue(int index) {
return index * 2;
}
#Override
public String getTestName(int index) {
return "test" + index;
}
};
}
// //////////////////////////////
// Fields
private final int testVal;
// //////////////////////////////
// Constructor
public PolySuiteExample(int testVal) {
this.testVal = testVal;
}
// //////////////////////////////
// Test
#Ignore
#Test
public void odd() {
assertFalse(testVal % 2 == 0);
}
#Test
public void even() {
assertTrue(testVal % 2 == 0);
}
}
You may also want to try JUnitParams: https://github.com/Pragmatists/JUnitParams
from junit4.8.2, you can create your own MyParameterized class by simply copy Parameterized class. change the getName() and testName() methods in TestClassRunnerForParameters.
None of it was working for me, so I got the source for Parameterized and modified it create a a new test runner. I didn't have to change much but IT WORKS!!!
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import org.junit.Assert;
import org.junit.internal.runners.ClassRoadie;
import org.junit.internal.runners.CompositeRunner;
import org.junit.internal.runners.InitializationError;
import org.junit.internal.runners.JUnit4ClassRunner;
import org.junit.internal.runners.MethodValidator;
import org.junit.internal.runners.TestClass;
import org.junit.runner.notification.RunNotifier;
public class LabelledParameterized extends CompositeRunner {
static class TestClassRunnerForParameters extends JUnit4ClassRunner {
private final Object[] fParameters;
private final String fParameterFirstValue;
private final Constructor<?> fConstructor;
TestClassRunnerForParameters(TestClass testClass, Object[] parameters, int i) throws InitializationError {
super(testClass.getJavaClass()); // todo
fParameters = parameters;
if (parameters != null) {
fParameterFirstValue = Arrays.asList(parameters).toString();
} else {
fParameterFirstValue = String.valueOf(i);
}
fConstructor = getOnlyConstructor();
}
#Override
protected Object createTest() throws Exception {
return fConstructor.newInstance(fParameters);
}
#Override
protected String getName() {
return String.format("%s", fParameterFirstValue);
}
#Override
protected String testName(final Method method) {
return String.format("%s%s", method.getName(), fParameterFirstValue);
}
private Constructor<?> getOnlyConstructor() {
Constructor<?>[] constructors = getTestClass().getJavaClass().getConstructors();
Assert.assertEquals(1, constructors.length);
return constructors[0];
}
#Override
protected void validate() throws InitializationError {
// do nothing: validated before.
}
#Override
public void run(RunNotifier notifier) {
runMethods(notifier);
}
}
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.METHOD)
public static #interface Parameters {
}
private final TestClass fTestClass;
public LabelledParameterized(Class<?> klass) throws Exception {
super(klass.getName());
fTestClass = new TestClass(klass);
MethodValidator methodValidator = new MethodValidator(fTestClass);
methodValidator.validateStaticMethods();
methodValidator.validateInstanceMethods();
methodValidator.assertValid();
int i = 0;
for (final Object each : getParametersList()) {
if (each instanceof Object[])
add(new TestClassRunnerForParameters(fTestClass, (Object[]) each, i++));
else
throw new Exception(String.format("%s.%s() must return a Collection of arrays.", fTestClass.getName(), getParametersMethod().getName()));
}
}
#Override
public void run(final RunNotifier notifier) {
new ClassRoadie(notifier, fTestClass, getDescription(), new Runnable() {
public void run() {
runChildren(notifier);
}
}).runProtected();
}
private Collection<?> getParametersList() throws IllegalAccessException, InvocationTargetException, Exception {
return (Collection<?>) getParametersMethod().invoke(null);
}
private Method getParametersMethod() throws Exception {
List<Method> methods = fTestClass.getAnnotatedMethods(Parameters.class);
for (Method each : methods) {
int modifiers = each.getModifiers();
if (Modifier.isStatic(modifiers) && Modifier.isPublic(modifiers))
return each;
}
throw new Exception("No public static parameters method on class " + getName());
}
public static Collection<Object[]> eachOne(Object... params) {
List<Object[]> results = new ArrayList<Object[]>();
for (Object param : params)
results.add(new Object[] { param });
return results;
}
}
You can create a method like
#Test
public void name() {
Assert.assertEquals("", inboundFileName);
}
While I wouldn't use it all the time it would be useful to figure out exactly which test number 143 is.
I make extensive use of static import for Assert and friends, so it is easy for me to redefine assertion:
private <T> void assertThat(final T actual, final Matcher<T> expected) {
Assert.assertThat(editThisToDisplaySomethingForYourDatum, actual, expected);
}
For example, you could add a "name" field to your test class, initialized in the constructor, and display that on test failure. Just pass it in as the first elements of your parameters array for each test. This also helps label the data:
public ExampleTest(final String testLabel, final int one, final int two) {
this.testLabel = testLabel;
// ...
}
#Parameters
public static Collection<Object[]> data() {
return asList(new Object[][]{
{"first test", 3, 4},
{"second test", 5, 6}
});
}
A workaround would be to catch and nest all Throwables into a new Throwable with a custom message that contains all information about the parameters. The message would appear in the stack trace.
This works whenever a test fails for all assertions, errors and exceptions as they are all subclasses of Throwable.
My code looks like this:
#RunWith(Parameterized.class)
public class ParameterizedTest {
int parameter;
public ParameterizedTest(int parameter) {
super();
this.parameter = parameter;
}
#Parameters
public static Collection<Object[]> data() {
return Arrays.asList(new Object[][] { {1}, {2} });
}
#Test
public void test() throws Throwable {
try {
assertTrue(parameter%2==0);
}
catch(Throwable thrown) {
throw new Throwable("parameter="+parameter, thrown);
}
}
}
The stack trace of the failed test is:
java.lang.Throwable: parameter=1
at sample.ParameterizedTest.test(ParameterizedTest.java:34)
Caused by: java.lang.AssertionError
at org.junit.Assert.fail(Assert.java:92)
at org.junit.Assert.assertTrue(Assert.java:43)
at org.junit.Assert.assertTrue(Assert.java:54)
at sample.ParameterizedTest.test(ParameterizedTest.java:31)
... 31 more
When you want the parameter values in test name then you can do something like -
#ParameterizedTest(name="{index} {arguments} then return false" )
#ValueSource(strings = {"false","FALSE"," ","123","abc"})
#DisplayName("When Feature JVM argument is ")
void test_Feature_JVM_Argument_Is_Empty_Or_Blank_Strings_Or_False(String params) {
System.setProperty("FeatureName", params);
assertFalse(Boolean.parseBoolean(System.getProperty("FeatureName")));
}
Test name will look like -
JUnit Test image
Check out JUnitParams as dsaff mentioned, works using ant to build parameterized test method descriptions in the html report.
This was after trying LabelledParameterized and finding that it although it works with eclipse it does not work with ant as far as the html report is concerned.
Cheers,
Since the parameter accessed (e.g. with "{0}" always returns the toString() representation, one workaround would be to make an anonymous implementation and override toString() in each case. For example:
public static Iterable<? extends Object> data() {
return Arrays.asList(
new MyObject(myParams...) {public String toString(){return "my custom test name";}},
new MyObject(myParams...) {public String toString(){return "my other custom test name";}},
//etc...
);
}
Parameterized test is calling toString() internally.
If you create an object wrapper overiding toString(), it will change the names of the test.
Here is an example, I answered in other post.
https://stackoverflow.com/a/67023556/1839360
For a more complex object you may do the following (example with JUnit 4):
#RunWith(Parameterized.class)
public class MainTest {
private static Object[] makeSample(String[] array, int expectedLength) {
return new Object[]{array, expectedLength, Arrays.toString(array)};
}
#Parameterized.Parameters(name = "for input {2} length should equal {1}")
public static Collection<Object[]> data() {
return Arrays.asList(
makeSample(new String[]{"a"}, 1),
makeSample(new String[]{"a", "b"}, 2)
);
}
private final int expectedLength;
private final String[] array;
public MainTest(String[] array, int expectedLength, String strArray) {
this.array = array;
this.expectedLength = expectedLength;
}
#Test
public void should_have_expected_length() {
assertEquals(expectedLength, array.length);
}
}
The trick here is to use one input parameter as a string describing either some part of input or the whole test case.
Before adding third parameter it looked like this
And after like this

Changing names of parameterized tests

Is there a way to set my own custom test case names when using parameterized tests in JUnit4?
I'd like to change the default — [Test class].runTest[n] — to something meaningful.
This feature has made it into JUnit 4.11.
To use change the name of parameterized tests, you say:
#Parameters(name="namestring")
namestring is a string, which can have the following special placeholders:
{index} - the index of this set of arguments. The default namestring is {index}.
{0} - the first parameter value from this invocation of the test.
{1} - the second parameter value
and so on
The final name of the test will be the name of the test method, followed by the namestring in brackets, as shown below.
For example (adapted from the unit test for the Parameterized annotation):
#RunWith(Parameterized.class)
static public class FibonacciTest {
#Parameters( name = "{index}: fib({0})={1}" )
public static Iterable<Object[]> data() {
return Arrays.asList(new Object[][] { { 0, 0 }, { 1, 1 }, { 2, 1 },
{ 3, 2 }, { 4, 3 }, { 5, 5 }, { 6, 8 } });
}
private final int fInput;
private final int fExpected;
public FibonacciTest(int input, int expected) {
fInput= input;
fExpected= expected;
}
#Test
public void testFib() {
assertEquals(fExpected, fib(fInput));
}
private int fib(int x) {
// TODO: actually calculate Fibonacci numbers
return 0;
}
}
will give names like testFib[1: fib(1)=1] and testFib[4: fib(4)=3]. (The testFib part of the name is the method name of the #Test).
Looking at JUnit 4.5, its runner clearly doesn't support that, as that logic is buried inside a private class inside the Parameterized class. You could not use the JUnit Parameterized runner, and create your own instead which would understand the concept of names (which leads to the question of how you might set a name ...).
From a JUnit perspective, it would be nice if instead of (or in addition to) just passing an increment, they would pass the comma delimited arguments. TestNG does this. If the feature is important to you, you can comment on the yahoo mailing list referenced at www.junit.org.
I recently came across the same problem when using JUnit 4.3.1. I implemented a new class which extends Parameterized called LabelledParameterized. It has been tested using JUnit 4.3.1, 4.4 and 4.5. It reconstructs the Description instance using the String representation of the first argument of each parameter array from the #Parameters method. You can see the code for this at:
http://code.google.com/p/migen/source/browse/trunk/java/src/.../LabelledParameterized.java?r=3789
and an example of its use at:
http://code.google.com/p/migen/source/browse/trunk/java/src/.../ServerBuilderTest.java?r=3789
The test description formats nicely in Eclipse which is what I wanted since this makes failed tests a lot easier to find! I will probably further refine and document the classes over the next few days/weeks. Drop the '?' part of the URLs if you want the bleeding edge. :-)
To use it, all you have to do is copy that class (GPL v3), and change #RunWith(Parameterized.class) to #RunWith(LabelledParameterized.class) assuming the first element of your parameter list is a sensible label.
I don't know if any later releases of JUnit address this issue but even if they did, I can't update JUnit since all my co-developers would have to update too and we have higher priorities than re-tooling. Hence the work in the class to be compilable by multiple versions of JUnit.
Note: there is some reflection jiggery-pokery so that it runs across the different JUnit versions as listed above. The version specifically for JUnit 4.3.1 can be found here and, for JUnit 4.4 and 4.5, here.
With Parameterized as a model, I wrote my own custom test runner / suite -- only took about half an hour. It's slightly different from darrenp's LabelledParameterized in that it lets you specify a name explicitly rather than relying on the first parameter's toString().
It also doesn't use arrays because I hate arrays. :)
public class PolySuite extends Suite {
// //////////////////////////////
// Public helper interfaces
/**
* Annotation for a method which returns a {#link Configuration}
* to be injected into the test class constructor
*/
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.METHOD)
public static #interface Config {
}
public static interface Configuration {
int size();
Object getTestValue(int index);
String getTestName(int index);
}
// //////////////////////////////
// Fields
private final List<Runner> runners;
// //////////////////////////////
// Constructor
/**
* Only called reflectively. Do not use programmatically.
* #param c the test class
* #throws Throwable if something bad happens
*/
public PolySuite(Class<?> c) throws Throwable {
super(c, Collections.<Runner>emptyList());
TestClass testClass = getTestClass();
Class<?> jTestClass = testClass.getJavaClass();
Configuration configuration = getConfiguration(testClass);
List<Runner> runners = new ArrayList<Runner>();
for (int i = 0, size = configuration.size(); i < size; i++) {
SingleRunner runner = new SingleRunner(jTestClass, configuration.getTestValue(i), configuration.getTestName(i));
runners.add(runner);
}
this.runners = runners;
}
// //////////////////////////////
// Overrides
#Override
protected List<Runner> getChildren() {
return runners;
}
// //////////////////////////////
// Private
private Configuration getConfiguration(TestClass testClass) throws Throwable {
return (Configuration) getConfigMethod(testClass).invokeExplosively(null);
}
private FrameworkMethod getConfigMethod(TestClass testClass) {
List<FrameworkMethod> methods = testClass.getAnnotatedMethods(Config.class);
if (methods.isEmpty()) {
throw new IllegalStateException("#" + Config.class.getSimpleName() + " method not found");
}
if (methods.size() > 1) {
throw new IllegalStateException("Too many #" + Config.class.getSimpleName() + " methods");
}
FrameworkMethod method = methods.get(0);
int modifiers = method.getMethod().getModifiers();
if (!(Modifier.isStatic(modifiers) && Modifier.isPublic(modifiers))) {
throw new IllegalStateException("#" + Config.class.getSimpleName() + " method \"" + method.getName() + "\" must be public static");
}
return method;
}
// //////////////////////////////
// Helper classes
private static class SingleRunner extends BlockJUnit4ClassRunner {
private final Object testVal;
private final String testName;
SingleRunner(Class<?> testClass, Object testVal, String testName) throws InitializationError {
super(testClass);
this.testVal = testVal;
this.testName = testName;
}
#Override
protected Object createTest() throws Exception {
return getTestClass().getOnlyConstructor().newInstance(testVal);
}
#Override
protected String getName() {
return testName;
}
#Override
protected String testName(FrameworkMethod method) {
return testName + ": " + method.getName();
}
#Override
protected void validateConstructor(List<Throwable> errors) {
validateOnlyOneConstructor(errors);
}
#Override
protected Statement classBlock(RunNotifier notifier) {
return childrenInvoker(notifier);
}
}
}
And an example:
#RunWith(PolySuite.class)
public class PolySuiteExample {
// //////////////////////////////
// Fixture
#Config
public static Configuration getConfig() {
return new Configuration() {
#Override
public int size() {
return 10;
}
#Override
public Integer getTestValue(int index) {
return index * 2;
}
#Override
public String getTestName(int index) {
return "test" + index;
}
};
}
// //////////////////////////////
// Fields
private final int testVal;
// //////////////////////////////
// Constructor
public PolySuiteExample(int testVal) {
this.testVal = testVal;
}
// //////////////////////////////
// Test
#Ignore
#Test
public void odd() {
assertFalse(testVal % 2 == 0);
}
#Test
public void even() {
assertTrue(testVal % 2 == 0);
}
}
You may also want to try JUnitParams: https://github.com/Pragmatists/JUnitParams
from junit4.8.2, you can create your own MyParameterized class by simply copy Parameterized class. change the getName() and testName() methods in TestClassRunnerForParameters.
None of it was working for me, so I got the source for Parameterized and modified it create a a new test runner. I didn't have to change much but IT WORKS!!!
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import org.junit.Assert;
import org.junit.internal.runners.ClassRoadie;
import org.junit.internal.runners.CompositeRunner;
import org.junit.internal.runners.InitializationError;
import org.junit.internal.runners.JUnit4ClassRunner;
import org.junit.internal.runners.MethodValidator;
import org.junit.internal.runners.TestClass;
import org.junit.runner.notification.RunNotifier;
public class LabelledParameterized extends CompositeRunner {
static class TestClassRunnerForParameters extends JUnit4ClassRunner {
private final Object[] fParameters;
private final String fParameterFirstValue;
private final Constructor<?> fConstructor;
TestClassRunnerForParameters(TestClass testClass, Object[] parameters, int i) throws InitializationError {
super(testClass.getJavaClass()); // todo
fParameters = parameters;
if (parameters != null) {
fParameterFirstValue = Arrays.asList(parameters).toString();
} else {
fParameterFirstValue = String.valueOf(i);
}
fConstructor = getOnlyConstructor();
}
#Override
protected Object createTest() throws Exception {
return fConstructor.newInstance(fParameters);
}
#Override
protected String getName() {
return String.format("%s", fParameterFirstValue);
}
#Override
protected String testName(final Method method) {
return String.format("%s%s", method.getName(), fParameterFirstValue);
}
private Constructor<?> getOnlyConstructor() {
Constructor<?>[] constructors = getTestClass().getJavaClass().getConstructors();
Assert.assertEquals(1, constructors.length);
return constructors[0];
}
#Override
protected void validate() throws InitializationError {
// do nothing: validated before.
}
#Override
public void run(RunNotifier notifier) {
runMethods(notifier);
}
}
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.METHOD)
public static #interface Parameters {
}
private final TestClass fTestClass;
public LabelledParameterized(Class<?> klass) throws Exception {
super(klass.getName());
fTestClass = new TestClass(klass);
MethodValidator methodValidator = new MethodValidator(fTestClass);
methodValidator.validateStaticMethods();
methodValidator.validateInstanceMethods();
methodValidator.assertValid();
int i = 0;
for (final Object each : getParametersList()) {
if (each instanceof Object[])
add(new TestClassRunnerForParameters(fTestClass, (Object[]) each, i++));
else
throw new Exception(String.format("%s.%s() must return a Collection of arrays.", fTestClass.getName(), getParametersMethod().getName()));
}
}
#Override
public void run(final RunNotifier notifier) {
new ClassRoadie(notifier, fTestClass, getDescription(), new Runnable() {
public void run() {
runChildren(notifier);
}
}).runProtected();
}
private Collection<?> getParametersList() throws IllegalAccessException, InvocationTargetException, Exception {
return (Collection<?>) getParametersMethod().invoke(null);
}
private Method getParametersMethod() throws Exception {
List<Method> methods = fTestClass.getAnnotatedMethods(Parameters.class);
for (Method each : methods) {
int modifiers = each.getModifiers();
if (Modifier.isStatic(modifiers) && Modifier.isPublic(modifiers))
return each;
}
throw new Exception("No public static parameters method on class " + getName());
}
public static Collection<Object[]> eachOne(Object... params) {
List<Object[]> results = new ArrayList<Object[]>();
for (Object param : params)
results.add(new Object[] { param });
return results;
}
}
You can create a method like
#Test
public void name() {
Assert.assertEquals("", inboundFileName);
}
While I wouldn't use it all the time it would be useful to figure out exactly which test number 143 is.
I make extensive use of static import for Assert and friends, so it is easy for me to redefine assertion:
private <T> void assertThat(final T actual, final Matcher<T> expected) {
Assert.assertThat(editThisToDisplaySomethingForYourDatum, actual, expected);
}
For example, you could add a "name" field to your test class, initialized in the constructor, and display that on test failure. Just pass it in as the first elements of your parameters array for each test. This also helps label the data:
public ExampleTest(final String testLabel, final int one, final int two) {
this.testLabel = testLabel;
// ...
}
#Parameters
public static Collection<Object[]> data() {
return asList(new Object[][]{
{"first test", 3, 4},
{"second test", 5, 6}
});
}
A workaround would be to catch and nest all Throwables into a new Throwable with a custom message that contains all information about the parameters. The message would appear in the stack trace.
This works whenever a test fails for all assertions, errors and exceptions as they are all subclasses of Throwable.
My code looks like this:
#RunWith(Parameterized.class)
public class ParameterizedTest {
int parameter;
public ParameterizedTest(int parameter) {
super();
this.parameter = parameter;
}
#Parameters
public static Collection<Object[]> data() {
return Arrays.asList(new Object[][] { {1}, {2} });
}
#Test
public void test() throws Throwable {
try {
assertTrue(parameter%2==0);
}
catch(Throwable thrown) {
throw new Throwable("parameter="+parameter, thrown);
}
}
}
The stack trace of the failed test is:
java.lang.Throwable: parameter=1
at sample.ParameterizedTest.test(ParameterizedTest.java:34)
Caused by: java.lang.AssertionError
at org.junit.Assert.fail(Assert.java:92)
at org.junit.Assert.assertTrue(Assert.java:43)
at org.junit.Assert.assertTrue(Assert.java:54)
at sample.ParameterizedTest.test(ParameterizedTest.java:31)
... 31 more
When you want the parameter values in test name then you can do something like -
#ParameterizedTest(name="{index} {arguments} then return false" )
#ValueSource(strings = {"false","FALSE"," ","123","abc"})
#DisplayName("When Feature JVM argument is ")
void test_Feature_JVM_Argument_Is_Empty_Or_Blank_Strings_Or_False(String params) {
System.setProperty("FeatureName", params);
assertFalse(Boolean.parseBoolean(System.getProperty("FeatureName")));
}
Test name will look like -
JUnit Test image
Check out JUnitParams as dsaff mentioned, works using ant to build parameterized test method descriptions in the html report.
This was after trying LabelledParameterized and finding that it although it works with eclipse it does not work with ant as far as the html report is concerned.
Cheers,
Since the parameter accessed (e.g. with "{0}" always returns the toString() representation, one workaround would be to make an anonymous implementation and override toString() in each case. For example:
public static Iterable<? extends Object> data() {
return Arrays.asList(
new MyObject(myParams...) {public String toString(){return "my custom test name";}},
new MyObject(myParams...) {public String toString(){return "my other custom test name";}},
//etc...
);
}
Parameterized test is calling toString() internally.
If you create an object wrapper overiding toString(), it will change the names of the test.
Here is an example, I answered in other post.
https://stackoverflow.com/a/67023556/1839360
For a more complex object you may do the following (example with JUnit 4):
#RunWith(Parameterized.class)
public class MainTest {
private static Object[] makeSample(String[] array, int expectedLength) {
return new Object[]{array, expectedLength, Arrays.toString(array)};
}
#Parameterized.Parameters(name = "for input {2} length should equal {1}")
public static Collection<Object[]> data() {
return Arrays.asList(
makeSample(new String[]{"a"}, 1),
makeSample(new String[]{"a", "b"}, 2)
);
}
private final int expectedLength;
private final String[] array;
public MainTest(String[] array, int expectedLength, String strArray) {
this.array = array;
this.expectedLength = expectedLength;
}
#Test
public void should_have_expected_length() {
assertEquals(expectedLength, array.length);
}
}
The trick here is to use one input parameter as a string describing either some part of input or the whole test case.
Before adding third parameter it looked like this
And after like this

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