Junit 3.8 setup

This allows for greater flexibility and enables Dependency Injection for constructors and methods. ParameterResolver defines the API for test extensions that wish to dynamically resolve parameters at runtime.

If a test class constructor, a test method , or a lifecycle method see Test Classes and Methods accepts a parameter, the parameter must be resolved at runtime by a registered ParameterResolver. TestInfoParameterResolver : if a constructor or method parameter is of type TestInfo , the TestInfoParameterResolver will supply an instance of TestInfo corresponding to the current container or test as the value for the parameter.

The TestInfo can then be used to retrieve information about the current container or test such as the display name, the test class, the test method, and associated tags.

The display name is either a technical name, such as the name of the test class or test method, or a custom name configured via DisplayName. The following demonstrates how to have TestInfo injected into a test constructor, BeforeEach method, and Test method. RepetitionInfo can then be used to retrieve information about the current repetition and the total number of repetitions for the corresponding RepeatedTest.

See Repeated Test Examples. The TestReporter can be used to publish additional data about the current test run. In addition, some IDEs print report entries to stdout or display them in the user interface for test results. While not intended to be production-ready, it demonstrates the simplicity and expressiveness of both the extension model and the parameter resolution process.

MyRandomParametersTest demonstrates how to inject random values into Test methods. For real-world use cases, check out the source code for the MockitoExtension and the SpringExtension. When the type of the parameter to inject is the only condition for your ParameterResolver , you can use the generic TypeBasedParameterResolver base class. The supportsParameters method is implemented behind the scenes and supports parameterized types. BeforeAll and AfterAll can either be declared on static methods in a test interface or on interface default methods if the test interface or test class is annotated with TestInstance Lifecycle.

Here are some examples. ExtendWith and Tag can be declared on a test interface so that classes that implement the interface automatically inherit its tags and extensions. Another possible application of this feature is to write tests for interface contracts.

For example, you can write tests for how implementations of Object. In your test class you can then implement both contract interfaces thereby inheriting the corresponding tests. JUnit Jupiter provides the ability to repeat a test a specified number of times by annotating a method with RepeatedTest and specifying the total number of repetitions desired.

Each invocation of a repeated test behaves like the execution of a regular Test method with full support for the same lifecycle callbacks and extensions.

The following example demonstrates how to declare a test named repeatedTest that will be automatically repeated 10 times. In addition to specifying the number of repetitions, a custom display name can be configured for each repetition via the name attribute of the RepeatedTest annotation.

Furthermore, the display name can be a pattern composed of a combination of static text and dynamic placeholders. The following placeholders are currently supported. Thus, the display names for individual repetitions of the previous repeatedTest example would be: repetition 1 of 10 , repetition 2 of 10 , etc. If you would like the display name of the RepeatedTest method included in the name of each repetition, you can define your own custom pattern or use the predefined RepeatedTest.

In order to retrieve information about the current repetition and the total number of repetitions programmatically, a developer can choose to have an instance of RepetitionInfo injected into a RepeatedTest , BeforeEach , or AfterEach method. The RepeatedTestsDemo class at the end of this section demonstrates several examples of repeated tests. The repeatedTest method is identical to example from the previous section; whereas, repeatedTestWithRepetitionInfo demonstrates how to have an instance of RepetitionInfo injected into a test to access the total number of repetitions for the current repeated test.

The next two methods demonstrate how to include a custom DisplayName for the RepeatedTest method in the display name of each repetition. Since the beforeEach method is annotated with BeforeEach it will get executed before each repetition of each repeated test. When using the ConsoleLauncher with the unicode theme enabled, execution of RepeatedTestsDemo results in the following output to the console.

Parameterized tests make it possible to run a test multiple times with different arguments. They are declared just like regular Test methods but use the ParameterizedTest annotation instead. In addition, you must declare at least one source that will provide the arguments for each invocation and then consume the arguments in the test method. The following example demonstrates a parameterized test that uses the ValueSource annotation to specify a String array as the source of arguments.

When executing the above parameterized test method, each invocation will be reported separately. For instance, the ConsoleLauncher will print output similar to the following.

In order to use parameterized tests you need to add a dependency on the junit-jupiter-params artifact. Please refer to Dependency Metadata for details. Parameterized test methods typically consume arguments directly from the configured source see Sources of Arguments following a one-to-one correlation between argument source index and method parameter index see examples in CsvSource.

However, a parameterized test method may also choose to aggregate arguments from the source into a single object passed to the method see Argument Aggregation.

Additional arguments may also be provided by a ParameterResolver e. Specifically, a parameterized test method must declare formal parameters according to the following rules. An aggregator is any parameter of type ArgumentsAccessor or any parameter annotated with AggregateWith. Arguments that implement java. AutoCloseable or java. Closeable which extends java. AutoCloseable will be automatically closed after AfterEach methods and AfterEachCallback extensions have been called for the current parameterized test invocation.

To prevent this from happening, set the autoCloseArguments attribute in ParameterizedTest to false. Out of the box, JUnit Jupiter provides quite a few source annotations. Each of the following subsections provides a brief overview and an example for each of them. Please refer to the Javadoc in the org. ValueSource is one of the simplest possible sources. It lets you specify a single array of literal values and can only be used for providing a single argument per parameterized test invocation.

For example, the following ParameterizedTest method will be invoked three times, with the values 1 , 2 , and 3 respectively.

In order to check corner cases and verify proper behavior of our software when it is supplied bad input , it can be useful to have null and empty values supplied to our parameterized tests. The following annotations serve as sources of null and empty values for parameterized tests that accept a single argument. NullSource : provides a single null argument to the annotated ParameterizedTest method.

EmptySource : provides a single empty argument to the annotated ParameterizedTest method for parameters of the following types: java. String , java. List , java. Set , java. Map , primitive arrays e. You can also combine NullSource , EmptySource , and ValueSource to test a wider range of null , empty , and blank input. The following example demonstrates how to achieve this for strings. Making use of the composed NullAndEmptySource annotation simplifies the above as follows.

When omitted, the declared type of the first method parameter is used. The test will fail if it does not reference an enum type. Thus, the value attribute is required in the above example because the method parameter is declared as TemporalUnit , i. Changing the method parameter type to ChronoUnit allows you to omit the explicit enum type from the annotation as follows.

The annotation provides an optional names attribute that lets you specify which constants shall be used, like in the following example. If omitted, all constants will be used. The EnumSource annotation also provides an optional mode attribute that enables fine-grained control over which constants are passed to the test method. For example, you can exclude names from the enum constant pool or specify regular expressions as in the following examples. MethodSource allows you to refer to one or more factory methods of the test class or external classes.

Factory methods within the test class must be static unless the test class is annotated with TestInstance Lifecycle. In addition, such factory methods must not accept any arguments.

Each factory method must generate a stream of arguments , and each set of arguments within the stream will be provided as the physical arguments for individual invocations of the annotated ParameterizedTest method. Generally speaking this translates to a Stream of Arguments i. The "arguments" within the stream can be supplied as an instance of Arguments , an array of objects e. If you only need a single parameter, you can return a Stream of instances of the parameter type as demonstrated in the following example.

If you do not explicitly provide a factory method name via MethodSource , JUnit Jupiter will search for a factory method that has the same name as the current ParameterizedTest method by convention. This is demonstrated in the following example. Streams for primitive types DoubleStream , IntStream , and LongStream are also supported as demonstrated by the following example. If a parameterized test method declares multiple parameters, you need to return a collection, stream, or array of Arguments instances or object arrays as shown below see the Javadoc for MethodSource for further details on supported return types.

In addition, Arguments. An external, static factory method can be referenced by providing its fully qualified method name as demonstrated in the following example. CsvSource allows you to express argument lists as comma-separated values i. Each string provided via the value attribute in CsvSource represents a CSV record and results in one invocation of the parameterized test. The default delimiter is a comma , , but you can use another character by setting the delimiter attribute.

Alternatively, the delimiterString attribute allows you to use a String delimiter instead of a single character. However, both delimiter attributes cannot be set simultaneously. By default, CsvSource uses a single quote ' as its quote character, but this can be changed via the quoteCharacter attribute. See the 'lemon, lime' value in the example above and in the table below. An empty, quoted value '' results in an empty String unless the emptyValue attribute is set; whereas, an entirely empty value is interpreted as a null reference.

By specifying one or more nullValues , a custom value can be interpreted as a null reference see the NIL example in the table below. An ArgumentConversionException is thrown if the target type of a null reference is a primitive type. Except within a quoted string, leading and trailing whitespace in a CSV column is trimmed by default. This behavior can be changed by setting the ignoreLeadingAndTrailingWhitespace attribute to true.

Each record within a text block represents a CSV record and results in one invocation of the parameterized test. The first record may optionally be used to supply CSV headers by setting the useHeadersInDisplayName attribute to true as in the example below. In contrast to CSV records supplied via the value attribute, a text block can contain comments. Any line beginning with a symbol will be treated as a comment and ignored. Note, however, that the symbol must be the first character on the line without any leading whitespace.

It is therefore recommended that the closing text block delimiter """ be placed either at the end of the last line of input or on the following line, left aligned with the rest of the input as can be seen in the example below which demonstrates formatting similar to a table. Thus, if you are using a programming language other than Java and your text block contains comments or new lines within quoted strings, you will need to ensure that there is no leading whitespace within your text block.

CsvFileSource lets you use comma-separated value CSV files from the classpath or the local file system. Each record from a CSV file results in one invocation of the parameterized test. The first record may optionally be used to supply CSV headers. If you would like for the headers to be used in the display names, you can set the useHeadersInDisplayName attribute to true. The following listing shows the generated display names for the first two parameterized test methods above.

The following listing shows the generated display names for the last parameterized test method above that uses CSV header names. In contrast to the default syntax used in CsvSource , CsvFileSource uses a double quote " as the quote character by default, but this can be changed via the quoteCharacter attribute.

See the "United States of America" value in the example above. An empty, quoted value "" results in an empty String unless the emptyValue attribute is set; whereas, an entirely empty value is interpreted as a null reference. By specifying one or more nullValues , a custom value can be interpreted as a null reference.

ArgumentsSource can be used to specify a custom, reusable ArgumentsProvider. Note that an implementation of ArgumentsProvider must be declared as either a top-level class or as a static nested class. To support use cases like CsvSource , JUnit Jupiter provides a number of built-in implicit type converters. The conversion process depends on the declared type of each method parameter. For example, if a ParameterizedTest declares a parameter of type TimeUnit and the actual type supplied by the declared source is a String , the string will be automatically converted into the corresponding TimeUnit enum constant.

In addition to implicit conversion from strings to the target types listed in the above table, JUnit Jupiter also provides a fallback mechanism for automatic conversion from a String to a given target type if the target type declares exactly one suitable factory method or a factory constructor as defined below. The name of the method can be arbitrary and need not follow any particular convention.

Note that the target type must be declared as either a top-level class or as a static nested class. For example, in the following ParameterizedTest method, the Book argument will be created by invoking the Book. Instead of relying on implicit argument conversion you may explicitly specify an ArgumentConverter to use for a certain parameter using the ConvertWith annotation like in the following example. Note that an implementation of ArgumentConverter must be declared as either a top-level class or as a static nested class.

If the converter is only meant to convert one type to another, you can extend TypedArgumentConverter to avoid boilerplate type checks. Explicit argument converters are meant to be implemented by test and extension authors. Thus, junit-jupiter-params only provides a single explicit argument converter that may also serve as a reference implementation: JavaTimeArgumentConverter.

It is used via the composed annotation JavaTimeConversionPattern. By default, each argument provided to a ParameterizedTest method corresponds to a single method parameter.

Consequently, argument sources which are expected to supply a large number of arguments can lead to large method signatures. In such cases, an ArgumentsAccessor can be used instead of multiple parameters. Using this API, you can access the provided arguments through a single argument passed to your test method. In addition, type conversion is supported as discussed in Implicit Conversion.

An instance of ArgumentsAccessor is automatically injected into any parameter of type ArgumentsAccessor. To use a custom aggregator, implement the ArgumentsAggregator interface and register it via the AggregateWith annotation on a compatible parameter in the ParameterizedTest method. The result of the aggregation will then be provided as an argument for the corresponding parameter when the parameterized test is invoked.

Note that an implementation of ArgumentsAggregator must be declared as either a top-level class or as a static nested class. The following example demonstrates this in action with a custom CsvToPerson annotation.

By default, the display name of a parameterized test invocation contains the invocation index and the String representation of all arguments for that specific invocation. Each of them is preceded by the parameter name unless the argument is only available via an ArgumentsAccessor or ArgumentAggregator , if present in the bytecode for Java, test code must be compiled with the -parameters compiler flag.

However, you can customize invocation display names via the name attribute of the ParameterizedTest annotation like in the following example. When executing the above method using the ConsoleLauncher you will see output similar to the following.

Please note that name is a MessageFormat pattern. Thus, a single quote ' needs to be represented as a doubled single quote '' in order to be displayed. When using MethodSource or ArgumentSource , you can give names to arguments. This name will be used if the argument is included in the invocation display name, like in the example below.

Each invocation of a parameterized test has the same lifecycle as a regular Test method. For example, BeforeEach methods will be executed before each invocation. You may at will mix regular Test methods and ParameterizedTest methods within the same test class. You may use ParameterResolver extensions with ParameterizedTest methods. However, method parameters that are resolved by argument sources need to come first in the argument list.

Since a test class may contain regular tests as well as parameterized tests with different parameter lists, values from argument sources are not resolved for lifecycle methods e. BeforeEach and test class constructors.

A TestTemplate method is not a regular test case but rather a template for test cases. As such, it is designed to be invoked multiple times depending on the number of invocation contexts returned by the registered providers.

Thus, it must be used in conjunction with a registered TestTemplateInvocationContextProvider extension. Each invocation of a test template method behaves like the execution of a regular Test method with full support for the same lifecycle callbacks and extensions.

Both describe methods that implement test cases. These test cases are static in the sense that they are fully specified at compile time, and their behavior cannot be changed by anything happening at runtime. Assumptions provide a basic form of dynamic behavior but are intentionally rather limited in their expressiveness. In addition to these standard tests a completely new kind of test programming model has been introduced in JUnit Jupiter. This new kind of test is a dynamic test which is generated at runtime by a factory method that is annotated with TestFactory.

In contrast to Test methods, a TestFactory method is not itself a test case but rather a factory for test cases. Thus, a dynamic test is the product of a factory. DynamicContainer instances are composed of a display name and a list of dynamic child nodes, enabling the creation of arbitrarily nested hierarchies of dynamic nodes.

DynamicTest instances will be executed lazily, enabling dynamic and even non-deterministic generation of test cases. Any Stream returned by a TestFactory will be properly closed by calling stream.

As with Test methods, TestFactory methods must not be private or static and may optionally declare parameters to be resolved by ParameterResolvers. A DynamicTest is a test case generated at runtime. It is composed of a display name and an Executable. Executable is a FunctionalInterface which means that the implementations of dynamic tests can be provided as lambda expressions or method references.

The following DynamicTestsDemo class demonstrates several examples of test factories and dynamic tests. The first method returns an invalid return type. Since an invalid return type cannot be detected at compile time, a JUnitException is thrown when it is detected at runtime. The next six methods are very simple examples that demonstrate the generation of a Collection , Iterable , Iterator , array, or Stream of DynamicTest instances.

Most of these examples do not really exhibit dynamic behavior but merely demonstrate the supported return types in principle. However, dynamicTestsFromStream and dynamicTestsFromIntStream demonstrate how easy it is to generate dynamic tests for a given set of strings or a range of input numbers.

The next method is truly dynamic in nature. Although the non-deterministic behavior of generateRandomNumberOfTests is of course in conflict with test repeatability and should thus be used with care, it serves to demonstrate the expressiveness and power of dynamic tests.

For demonstration purposes, the dynamicNodeSingleTest method generates a single DynamicTest instead of a stream, and the dynamicNodeSingleContainer method generates a nested hierarchy of dynamic tests utilizing DynamicContainer.

The JUnit Platform provides TestSource , a representation of the source of a test or container used to navigate to its location by IDEs and build tools. The TestSource for a dynamic test or dynamic container can be constructed from a java. URI which can be supplied via the DynamicTest.

Foo bar java. String, java. Please refer to the Javadoc for DiscoverySelectors. The Timeout annotation allows one to declare that a test, test factory, test template, or lifecycle method should fail if its execution time exceeds a given duration. The time unit for the duration defaults to seconds but is configurable.

Contrary to the assertTimeoutPreemptively assertion, the execution of the annotated method proceeds in the main thread of the test. If the timeout is exceeded, the main thread is interrupted from another thread.

This is done to ensure interoperability with frameworks such as Spring that make use of mechanisms that are sensitive to the currently running thread — for example, ThreadLocal transaction management. To apply the same timeout to all test methods within a test class and all of its Nested classes, you can declare the Timeout annotation at the class level.

It will then be applied to all test, test factory, and test template methods within that class and its Nested classes unless overridden by a Timeout annotation on a specific method or Nested class. Please note that Timeout annotations declared at the class level are not applied to lifecycle methods.

Declaring Timeout on a TestFactory method checks that the factory method returns within the specified duration but does not verify the execution time of each individual DynamicTest generated by the factory. Please use assertTimeout or assertTimeoutPreemptively for that purpose.

If Timeout is present on a TestTemplate method — for example, a RepeatedTest or ParameterizedTest — each invocation will have the given timeout applied to it. The following configuration parameters can be used to specify global timeouts for all methods of a certain category unless they or an enclosing test class is annotated with Timeout :.

More specific configuration parameters override less specific ones. For example, junit. The space between the number and the unit may be omitted.

Specifying no unit is equivalent to using seconds. When dealing with asynchronous code, it is common to write tests that poll while waiting for something to happen before performing any assertions.

In some cases you can rewrite the logic to use a CountDownLatch or another synchronization mechanism, but sometimes that is not possible — for example, if the subject under test sends a message to a channel in an external message broker and assertions cannot be performed until the message has been successfully sent through the channel.

By configuring a timeout for an asynchronous test that polls, you can ensure that the test does not execute indefinitely. This technique can be used to implement "poll until" logic very easily. When stepping through your code in a debug session, a fixed timeout limit may influence the result of the test, e.

JUnit Jupiter supports the junit. The default mode is enabled. A VM runtime is considered to run in debug mode when one of its input parameters starts with -agentlib:jdwp. By default, JUnit Jupiter tests are run sequentially in a single thread.

To enable parallel execution, set the junit. Please note that enabling this property is only the first step required to execute tests in parallel.

If enabled, test classes and methods will still be executed sequentially by default. Whether or not a node in the test tree is executed concurrently is controlled by its execution mode.

The following two modes are available. Force execution in the same thread used by the parent. For example, when used on a test method, the test method will be executed in the same thread as any BeforeAll or AfterAll methods of the containing test class.

You can change the default by setting the junit. Alternatively, you can use the Execution annotation to change the execution mode for the annotated element and its subelements if any which allows you to activate parallel execution for individual test classes, one by one. The default execution mode is applied to all nodes of the test tree with a few notable exceptions, namely test classes that use the Lifecycle. In the former case, test authors have to ensure that the test class is thread-safe; in the latter, concurrent execution might conflict with the configured execution order.

In addition, you can configure the default execution mode for top-level classes by setting the junit. By combining both configuration parameters, you can configure classes to run in parallel but their methods in the same thread:. The opposite combination will run all methods within one class in parallel, but top-level classes will run sequentially:.

The following diagram illustrates how the execution of two top-level test classes A and B with two test methods per class behaves for all four combinations of junit. If the junit. Properties such as the desired parallelism and the maximum pool size can be configured using a ParallelExecutionConfigurationStrategy. The JUnit Platform provides two implementations out of the box: dynamic and fixed. Alternatively, you may implement a custom strategy. To select a strategy, set the junit.

Uses the mandatory junit. Allows you to specify a custom ParallelExecutionConfigurationStrategy implementation via the mandatory junit. If no configuration strategy is set, JUnit Jupiter uses the dynamic configuration strategy with a factor of 1. In addition to controlling the execution mode using the Execution annotation, JUnit Jupiter provides another annotation-based declarative synchronization mechanism. The ResourceLock annotation allows you to declare that a test class or method uses a specific shared resource that requires synchronized access to ensure reliable test execution.

The shared resource is identified by a unique name which is a String. If the tests in the following example were run in parallel without the use of ResourceLock , they would be flaky.

Sometimes they would pass, and at other times they would fail due to the inherent race condition of writing and then reading the same JVM System Property. When access to shared resources is declared using the ResourceLock annotation, the JUnit Jupiter engine uses this information to ensure that no conflicting tests are run in parallel. If most of your test classes can be run in parallel without any synchronization but you have some test classes that need to run in isolation, you can mark the latter with the Isolated annotation.

Tests in such classes are executed sequentially without any other tests running at the same time. In addition to the String that uniquely identifies the shared resource, you may specify an access mode. The built-in TempDirectory extension is used to create and clean up a temporary directory for an individual test or all tests in a test class. It is registered by default. To use it, annotate a field of type java.

Path or java. File with TempDir or add a parameter of type java. File annotated with TempDir to a lifecycle method or test method. For example, the following test declares a parameter annotated with TempDir for a single test method, creates and writes to a file in the temporary directory, and checks its content.

TempDir is not supported on constructor parameters. If you wish to retain a single reference to a temp directory across lifecycle methods and the current test method, please use field injection by annotating an instance field with TempDir. The following example stores a shared temporary directory in a static field.

This allows the same sharedTempDir to be used in all lifecycle methods and test methods of the test class. For better isolation, you should use an instance field so that each test method uses a separate directory. Although the JUnit Jupiter programming model and extension model will not support JUnit 4 features such as Rules and Runners natively, it is not expected that source code maintainers will need to update all of their existing tests, test extensions, and custom build test infrastructure to migrate to JUnit Jupiter.

Since all classes and annotations specific to JUnit Jupiter reside under a new org. Furthermore, since the JUnit team will continue to provide maintenance and bug fix releases for the JUnit 4. Just make sure that the junit-vintage-engine artifact is in your test runtime path. See the example projects in the junit5-samples repository to find out how this is done with Gradle and Maven.

For example, if a test method is annotated with Category Example. Similar to the Categories runner in JUnit 4, this information can be used to filter the discovered tests before executing them see Running Tests for details. The following are topics that you should be aware of when migrating existing JUnit 4 tests to JUnit Jupiter. Note that you may continue to use assertion methods from org. Assert or any other assertion library such as AssertJ , Hamcrest , Truth , etc.

Note that JUnit Jupiter 5. Assume class for assumptions. Ignore no longer exists: use Disabled or one of the other built-in execution conditions instead. The JUnit team realizes, however, that many organizations, especially large ones, are likely to have large JUnit 4 code bases that make use of custom rules.

To serve these organizations and enable a gradual migration path the JUnit team has decided to support a selection of JUnit 4 rules verbatim within JUnit Jupiter. This support is based on adapters and is limited to those rules that are semantically compatible to the JUnit Jupiter extension model, i. The junit-jupiter-migrationsupport module from JUnit Jupiter currently supports the following three Rule types including subclasses of these types:.

ExternalResource including org. As in JUnit 4, Rule-annotated fields as well as methods are supported. By using these class-level extensions on a test class such Rule implementations in legacy code bases can be left unchanged including the JUnit 4 rule import statements.

This limited form of Rule support can be switched on by the class-level annotation EnableRuleMigrationSupport. This annotation is a composed annotation which enables all rule migration support extensions: VerifierSupport , ExternalResourceSupport , and ExpectedExceptionSupport. However, if you intend to develop a new extension for JUnit 5 please use the new extension model of JUnit Jupiter instead of the rule-based model of JUnit 4.

To use Ignore with JUnit Jupiter based tests, configure a test dependency on the junit-jupiter-migrationsupport module in your build and then annotate your test class with ExtendWith IgnoreCondition.

The IgnoreCondition is an ExecutionCondition that disables test classes or test methods that are annotated with Ignore. Note, however, that it is recommended to use IDEA In order to use a different JUnit 5 version e. If you are using an editor or IDE other than one of those listed in the previous sections, the JUnit team provides two alternative solutions to assist you in using JUnit 5.

Starting with version 4. To enable it, you just need to specify useJUnitPlatform within a test task declaration in build. Filtering by tags , tag expressions , or engines is also supported:. Please refer to the official Gradle documentation for a comprehensive list of options.

The standard Gradle test task currently does not provide a dedicated DSL to set JUnit Platform configuration parameters to influence test discovery and execution. However, you can provide configuration parameters within the build script via system properties as shown below or via the junit-platform.

In order to run any tests at all, a TestEngine implementation must be on the classpath. To configure support for JUnit Jupiter based tests, configure a testImplementation dependency on the dependency-aggregating JUnit Jupiter artifact similar to the following.

JUL to emit warnings and debug information. Please refer to the official documentation of LogManager for configuration options. If more checks needed about parameters and message of the thrown exceptions we must follow the well-known try-catch practice. If we don't want to run some test methods for some reason it's possible to ignore it by using Ignore. Test needn't have to be removed. Ignore can follow or precede it. It can have a String-type parameter with the reason why is the test ignored.

Test won't run and the runner will sign the fact that it was ignored. We can say Ignore for the whole class but it's slightly differs from ignoring each test methods one by one, because AfterClass and BeforeClass will run in the latter case.

There is a new assert which compares object arrays, however many 12 assert method removed because of the autoboxing feature. More precisely DevX writes this happened but oddly I can use these old asserts in the TestCase class.

When using native asserts, instead of the JUnit's assertException , the general java. AssertionError will raise in certain cases. In JUnit4 there is no suite method. We can create an empty class which has the runnable classes in annotation: RunWith Suite. For an example, the org. Parameterized , which drives the test by a set of parameters we defined previously. A public static method with Parameters annotation is needed which returns a Collection and a public constructor is needed which can accept elements of the previous Collection.

If the Collection contains integer pairs, constructor must have two integer parameters. The runner walks through on the Collection, calls the constructor and the test methods for every element of the Collection. DevX article has a good example about this on the third page. Listing 2. JUnit4 doesn't make difference between expected failures and wrongly written test cases. This is a stepback. Test can be runned by java —ea org. It can run 3. Practically 3. When having both old and new JUnit on the classpath they may impact.

It least I had securityException. I've heard about a so called assertThat method. Theoretically 4. JUnitCore is a facade for running tests. It supports running JUnit 4 tests, JUnit 3.

To run tests from the command line, run java org. For one-shot test runs, use the static method runClasses Class[]. Now create a java class file named TestRunner. It imports the JUnitCore class and uses the runClasses method that takes the test class name as its parameter.

Test suite is used to bundle a few unit test cases and run them together. Create a java class file named TestSuite. Sometimes it so happens that our code is not completely ready while running a test case. As a result, the test case fails. The Ignore annotation helps in this scenario. Add Ignore at class level. Now run the Test Runner, which will not run any test case defined in the provided Test Case class.

JUnit provides a handy option of Timeout. If a test case takes more time than the specified number of milliseconds, then JUnit will automatically mark it as failed. The timeout parameter is used along with Test annotation. Let us see the Test timeout in action. Create a java test class, say, TestJunit. Add a timeout of to testPrintMessage test case. JUnit provides an option of tracing the exception handling of code.

You can test whether the code throws a desired exception or not. The expected parameter is used along with Test annotation. Let us see Test expected in action. Create a java test class called TestJunit. Add an expected exception ArithmeticException to the testPrintMessage test case. JUnit 4 has introduced a new feature called parameterized tests. Parameterized tests allow a developer to run the same test over and over again using different values. There are five steps that you need to follow to create a parameterized test.

Annotate test class with RunWith Parameterized. Create a public static method annotated with Parameters that returns a Collection of Objects as Array as test data set.

The test case will be invoked once for each row of data. Let us see parameterized tests in action. Create a java test class, say, PrimeNumberCheckerTest. Create a java class file named PrimeNumberCheckerTest. Download Apache Ant based on the operating system you are working on. Let us assume the Ant libraries are stored in the folder apache-ant We assume that your Eclipse has inbuilt JUnit plugin. Unzip the downloaded zip file in the plugin folder of the Eclipse.

Finally restart Eclipse. Create a project TestJunit in Eclipse at any location. Then create a class MessageUtil to test in the project. The intent of Cactus is to lower the cost of writing tests for server-side code. It uses JUnit and extends it.

Cactus implements an in-container strategy that executes the tests inside a container. Cactus Framework is the heart of Cactus. It is the engine that provides the API to write Cactus tests.