Assert that an Option[String] is None.
Assert that an Option[String] is None.
If the condition is None, this method returns normally.
Else, it throws TestFailedException with the String
value of the Some included in the TestFailedException's
detail message.
This form of assert is usually called in conjunction with an
implicit conversion to Equalizer, using a === comparison, as in:
assert(a === b)
For more information on how this mechanism works, see the documentation for
Equalizer.
the Option[String] to assert
Assert that an Option[String] is None.
Assert that an Option[String] is None.
If the condition is None, this method returns normally.
Else, it throws TestFailedException with the String
value of the Some, as well as the
String obtained by invoking toString on the
specified message,
included in the TestFailedException's detail message.
This form of assert is usually called in conjunction with an
implicit conversion to Equalizer, using a === comparison, as in:
assert(a === b, "extra info reported if assertion fails")
For more information on how this mechanism works, see the documentation for
Equalizer.
the Option[String] to assert
An objects whose toString method returns a message to include in a failure report.
Assert that a boolean condition, described in String
message, is true.
Assert that a boolean condition, described in String
message, is true.
If the condition is true, this method returns normally.
Else, it throws TestFailedException with the
String obtained by invoking toString on the
specified message as the exception's detail message.
the boolean condition to assert
An objects whose toString method returns a message to include in a failure report.
Assert that a boolean condition is true.
Assert that a boolean condition is true.
If the condition is true, this method returns normally.
Else, it throws TestFailedException.
the boolean condition to assert
Implicit conversion from Any to Equalizer, used to enable
assertions with === comparisons.
Implicit conversion from Any to Equalizer, used to enable
assertions with === comparisons.
For more information on this mechanism, see the documentation for Equalizer.
Because trait Suite mixes in Assertions, this implicit conversion will always be
available by default in ScalaTest Suites. This is the only implicit conversion that is in scope by default in every
ScalaTest Suite. Other implicit conversions offered by ScalaTest, such as those that support the matchers DSL
or invokePrivate, must be explicitly invited into your test code, either by mixing in a trait or importing the
members of its companion object. The reason ScalaTest requires you to invite in implicit conversions (with the exception of the
implicit conversion for === operator) is because if one of ScalaTest's implicit conversions clashes with an
implicit conversion used in the code you are trying to test, your program won't compile. Thus there is a chance that if you
are ever trying to use a library or test some code that also offers an implicit conversion involving a === operator,
you could run into the problem of a compiler error due to an ambiguous implicit conversion. If that happens, you can turn off
the implicit conversion offered by this convertToEqualizer method simply by overriding the method in your
Suite subclass, but not marking it as implicit:
// In your Suite subclass override def convertToEqualizer(left: Any) = new Equalizer(left)
the object whose type to convert to Equalizer.
Executes the test specified as testName in this Suite with the specified configMap, printing
results to the standard output.
Executes the test specified as testName in this Suite with the specified configMap, printing
results to the standard output.
This method implementation calls run on this Suite, passing in:
testName - Some(testName)reporter - a reporter that prints to the standard outputstopper - a Stopper whose apply method always returns falsefilter - a Filter constructed with None for tagsToInclude and Set()
for tagsToExcludeconfigMap - the specified configMap Map[String, Any]distributor - Nonetracker - a new TrackerThis method serves as a convenient way to execute a single test, passing in some objects via the configMap, especially from
within the Scala interpreter.
Note: In ScalaTest, the terms "execute" and "run" basically mean the same thing and
can be used interchangably. The reason this convenience method and its three overloaded forms
aren't named run is described the documentation of the overloaded form that
takes no parameters: execute().
the name of one test to run.
a Map of key-value pairs that can be used by the executing Suite of tests.
Executes the test specified as testName in this Suite, printing results to the standard output.
Executes the test specified as testName in this Suite, printing results to the standard output.
This method implementation calls run on this Suite, passing in:
testName - Some(testName)reporter - a reporter that prints to the standard outputstopper - a Stopper whose apply method always returns falsefilter - a Filter constructed with None for tagsToInclude and Set()
for tagsToExcludeconfigMap - an empty Map[String, Any]distributor - Nonetracker - a new TrackerThis method serves as a convenient way to run a single test, especially from within the Scala interpreter.
Note: In ScalaTest, the terms "execute" and "run" basically mean the same thing and
can be used interchangably. The reason this convenience method and its three overloaded forms
aren't named run is described the documentation of the overloaded form that
takes no parameters: execute().
the name of one test to run.
Executes this Suite with the specified configMap, printing results to the standard output.
Executes this Suite with the specified configMap, printing results to the standard output.
This method implementation calls run on this Suite, passing in:
testName - Nonereporter - a reporter that prints to the standard outputstopper - a Stopper whose apply method always returns falsefilter - a Filter constructed with None for tagsToInclude and Set()
for tagsToExcludeconfigMap - the specified configMap Map[String, Any]distributor - Nonetracker - a new TrackerThis method serves as a convenient way to execute a Suite, passing in some objects via the configMap, especially from within the Scala interpreter.
Note: In ScalaTest, the terms "execute" and "run" basically mean the same thing and
can be used interchangably. The reason this convenience method and its three overloaded forms
aren't named run is described the documentation of the overloaded form that
takes no parameters: execute().
a Map of key-value pairs that can be used by the executing Suite of tests.
Executes this Suite, printing results to the standard output.
Executes this Suite, printing results to the standard output.
This method implementation calls run on this Suite, passing in:
testName - Nonereporter - a reporter that prints to the standard outputstopper - a Stopper whose apply method always returns falsefilter - a Filter constructed with None for tagsToInclude and Set()
for tagsToExcludeconfigMap - an empty Map[String, Any]distributor - Nonetracker - a new TrackerThis method serves as a convenient way to execute a Suite, especially from
within the Scala interpreter.
Note: In ScalaTest, the terms "execute" and "run" basically mean the same thing and
can be used interchangably. The reason this convenience method and its three overloaded forms
aren't named run
is because junit.framework.TestCase declares a run method
that takes no arguments but returns a junit.framework.TestResult. That
run method would not overload with this method if it were named run,
because it would have the same parameters but a different return type than the one
defined in TestCase. To facilitate integration with JUnit 3, therefore,
these convenience "run" methods are named execute. In particular, this allows trait
org.scalatest.junit.JUnit3Suite to extend both org.scalatest.Suite and
junit.framework.TestCase, which enables the creating of classes that
can be run with either ScalaTest or JUnit 3.
Expect that the value passed as expected equals the value passed as actual.
Expect that the value passed as expected equals the value passed as actual.
If the actual value equals the expected value
(as determined by ==), expect returns
normally. Else, expect throws an
TestFailedException whose detail message includes the expected and actual values.
the expected value
the actual value, which should equal the passed expected value
Expect that the value passed as expected equals the value passed as actual.
Expect that the value passed as expected equals the value passed as actual.
If the actual equals the expected
(as determined by ==), expect returns
normally. Else, if actual is not equal to expected, expect throws an
TestFailedException whose detail message includes the expected and actual values, as well as the String
obtained by invoking toString on the passed message.
the expected value
An object whose toString method returns a message to include in a failure report.
the actual value, which should equal the passed expected value
The total number of tests that are expected to run when this Suite's run method is invoked.
The total number of tests that are expected to run when this Suite's run method is invoked.
This trait's implementation of this method returns the sum of:
testNames List, minus the number of tests marked as ignoredexpectedTestCount on every nested Suite contained in
nestedSuitesa Filter with which to filter tests to count based on their tags
Throws TestFailedException, with the passed
Throwable cause, to indicate a test failed.
Throws TestFailedException, with the passed
Throwable cause, to indicate a test failed.
The getMessage method of the thrown TestFailedException
will return cause.toString().
a Throwable that indicates the cause of the failure.
Throws TestFailedException, with the passed
String message as the exception's detail
message and Throwable cause, to indicate a test failed.
Throws TestFailedException, with the passed
String message as the exception's detail
message and Throwable cause, to indicate a test failed.
A message describing the failure.
A Throwable that indicates the cause of the failure.
Throws TestFailedException, with the passed
String message as the exception's detail
message, to indicate a test failed.
Throws TestFailedException, with the passed
String message as the exception's detail
message, to indicate a test failed.
A message describing the failure.
Throws TestFailedException to indicate a test failed.
Throws TestFailedException to indicate a test failed.
Intercept and return an exception that's expected to be thrown by the passed function value.
Intercept and return an exception that's expected to
be thrown by the passed function value. The thrown exception must be an instance of the
type specified by the type parameter of this method. This method invokes the passed
function. If the function throws an exception that's an instance of the specified type,
this method returns that exception. Else, whether the passed function returns normally
or completes abruptly with a different exception, this method throws TestFailedException.
Note that the type specified as this method's type parameter may represent any subtype of
AnyRef, not just Throwable or one of its subclasses. In
Scala, exceptions can be caught based on traits they implement, so it may at times make sense
to specify a trait that the intercepted exception's class must mix in. If a class instance is
passed for a type that could not possibly be used to catch an exception (such as String,
for example), this method will complete abruptly with a TestFailedException.
the function value that should throw the expected exception
an implicit Manifest representing the type of the specified
type parameter.
the intercepted exception, if it is of the expected type
A List of this Suite object's nested Suites.
A List of this Suite object's nested Suites. If this Suite contains no nested Suites,
this method returns an empty List. This trait's implementation of this method returns an empty List.
Throws TestPendingException to indicate a test is pending.
Throws TestPendingException to indicate a test is pending.
A pending test is one that has been given a name but is not yet implemented. The purpose of pending tests is to facilitate a style of testing in which documentation of behavior is sketched out before tests are written to verify that behavior (and often, the before the behavior of the system being tested is itself implemented). Such sketches form a kind of specification of what tests and functionality to implement later.
To support this style of testing, a test can be given a name that specifies one
bit of behavior required by the system being tested. The test can also include some code that
sends more information about the behavior to the reporter when the tests run. At the end of the test,
it can call method pending, which will cause it to complete abruptly with TestPendingException.
Because tests in ScalaTest can be designated as pending with TestPendingException, both the test name and any information
sent to the reporter when running the test can appear in the report of a test run. (In other words,
the code of a pending test is executed just like any other test.) However, because the test completes abruptly
with TestPendingException, the test will be reported as pending, to indicate
the actual test, and possibly the functionality it is intended to test, has not yet been implemented.
Note: This method always completes abruptly with a TestPendingException. Thus it always has a side
effect. Methods with side effects are usually invoked with parentheses, as in pending(). This
method is defined as a parameterless method, in flagrant contradiction to recommended Scala style, because it
forms a kind of DSL for pending tests. It enables tests in suites such as FunSuite or Spec
to be denoted by placing "(pending)" after the test name, as in:
test("that style rules are not laws") (pending)
Readers of the code see "pending" in parentheses, which looks like a little note attached to the test name to indicate
it is pending. Whereas "(pending()) looks more like a method call, "(pending)" lets readers
stay at a higher level, forgetting how it is implemented and just focusing on the intent of the programmer who wrote the code.
Execute the passed block of code, and if it completes abruptly, throw TestPendingException, else
throw TestFailedException.
Execute the passed block of code, and if it completes abruptly, throw TestPendingException, else
throw TestFailedException.
This method can be used to temporarily change a failing test into a pending test in such a way that it will
automatically turn back into a failing test once the problem originally causing the test to fail has been fixed.
At that point, you need only remove the pendingUntilFixed call. In other words, a
pendingUntilFixed surrounding a block of code that isn't broken is treated as a test failure.
The motivation for this behavior is to encourage people to remove pendingUntilFixed calls when
there are no longer needed.
This method facilitates a style of testing in which tests are written before the code they test. Sometimes you may
encounter a test failure that requires more functionality than you want to tackle without writing more tests. In this
case you can mark the bit of test code causing the failure with pendingUntilFixed. You can then write more
tests and functionality that eventually will get your production code to a point where the original test won't fail anymore.
At this point the code block marked with pendingUntilFixed will no longer throw an exception (because the
problem has been fixed). This will in turn cause pendingUntilFixed to throw TestFailedException
with a detail message explaining you need to go back and remove the pendingUntilFixed call as the problem orginally
causing your test code to fail has been fixed.
a block of code, which if it completes abruptly, should trigger a TestPendingException
Runs this suite of tests.
Runs this suite of tests.
If testName is None, this trait's implementation of this method
calls these two methods on this object in this order:
runNestedSuites(report, stopper, tagsToInclude, tagsToExclude, configMap, distributor)runTests(testName, report, stopper, tagsToInclude, tagsToExclude, configMap)If testName is defined, then this trait's implementation of this method
calls runTests, but does not call runNestedSuites. This behavior
is part of the contract of this method. Subclasses that override run must take
care not to call runNestedSuites if testName is defined. (The
OneInstancePerTest trait depends on this behavior, for example.)
Subclasses and subtraits that override this run method can implement them without
invoking either the runTests or runNestedSuites methods, which
are invoked by this trait's implementation of this method. It is recommended, but not required,
that subclasses and subtraits that override run in a way that does not
invoke runNestedSuites also override runNestedSuites and make it
final. Similarly it is recommended, but not required,
that subclasses and subtraits that override run in a way that does not
invoke runTests also override runTests (and runTest,
which this trait's implementation of runTests calls) and make it
final. The implementation of these final methods can either invoke the superclass implementation
of the method, or throw an UnsupportedOperationException if appropriate. The
reason for this recommendation is that ScalaTest includes several traits that override
these methods to allow behavior to be mixed into a Suite. For example, trait
BeforeAndAfterEach overrides runTestss. In a Suite
subclass that no longer invokes runTests from run, the
BeforeAndAfterEach trait is not applicable. Mixing it in would have no effect.
By making runTests final in such a Suite subtrait, you make
the attempt to mix BeforeAndAfterEach into a subclass of your subtrait
a compiler error. (It would fail to compile with a complaint that BeforeAndAfterEach
is trying to override runTests, which is a final method in your trait.)
an optional name of one test to run. If None, all relevant tests should be run.
I.e., None acts like a wildcard that means run all relevant tests in this Suite.
the Reporter to which results will be reported
the Stopper that will be consulted to determine whether to stop execution early.
a Filter with which to filter tests based on their tags
a Map of key-value pairs that can be used by the executing Suite of tests.
an optional Distributor, into which to put nested Suites to be run
by another entity, such as concurrently by a pool of threads. If None, nested Suites will be run sequentially.
a Tracker tracking Ordinals being fired by the current thread.
Run zero to many of this Suite's nested Suites.
Run zero to many of this Suite's nested Suites.
If the passed distributor is None, this trait's
implementation of this method invokes run on each
nested Suite in the List obtained by invoking nestedSuites.
If a nested Suite's run
method completes abruptly with an exception, this trait's implementation of this
method reports that the Suite aborted and attempts to run the
next nested Suite.
If the passed distributor is defined, this trait's implementation
puts each nested Suite
into the Distributor contained in the Some, in the order in which the
Suites appear in the List returned by nestedSuites, passing
in a new Tracker obtained by invoking nextTracker on the Tracker
passed to this method.
Implementations of this method are responsible for ensuring SuiteStarting events
are fired to the Reporter before executing any nested Suite, and either SuiteCompleted
or SuiteAborted after executing any nested Suite.
the Reporter to which results will be reported
the Stopper that will be consulted to determine whether to stop execution early.
a Filter with which to filter tests based on their tags
a Map of key-value pairs that can be used by the executing Suite of tests.
an optional Distributor, into which to put nested Suites to be run
by another entity, such as concurrently by a pool of threads. If None, nested Suites will be run sequentially.
a Tracker tracking Ordinals being fired by the current thread.
Run a test.
Run a test.
This trait's implementation uses Java reflection to invoke on this object the test method identified by the passed testName.
Implementations of this method are responsible for ensuring a TestStarting event
is fired to the Reporter before executing any test, and either TestSucceeded,
TestFailed, or TestPending after executing any nested
Suite. (If a test is marked with the org.scalatest.Ignore tag, the
runTests method is responsible for ensuring a TestIgnored event is fired and that
this runTest method is not invoked for that ignored test.)
the name of one test to run.
the Reporter to which results will be reported
the Stopper that will be consulted to determine whether to stop execution early.
a Map of key-value pairs that can be used by the executing Suite of tests.
a Tracker tracking Ordinals being fired by the current thread.
Run zero to many of this Suite's tests.
Run zero to many of this Suite's tests.
This method takes a testName parameter that optionally specifies a test to invoke.
If testName is defined, this trait's implementation of this method
invokes runTest on this object, passing in:
testName - the String value of the testName Option passed
to this methodreporter - the Reporter passed to this method, or one that wraps and delegates to itstopper - the Stopper passed to this method, or one that wraps and delegates to itconfigMap - the configMap Map passed to this method, or one that wraps and delegates to itThis method takes a Filter, which encapsulates an optional Set of tag names that should be included
(tagsToInclude) and a Set that should be excluded (tagsToExclude), when deciding which
of this Suite's tests to run.
If tagsToInclude is None, all tests will be run
except those those belonging to tags listed in the tagsToExclude Set. If tagsToInclude is defined, only tests
belonging to tags mentioned in the tagsToInclude Set, and not mentioned in the tagsToExcludeSet
will be run. However, if testName is defined, tagsToInclude and tagsToExclude are essentially ignored.
Only if testName is None will tagsToInclude and tagsToExclude be consulted to
determine which of the tests named in the testNames Set should be run. This trait's implementation
behaves this way, and it is part of the general contract of this method, so all overridden forms of this method should behave
this way as well. For more information on test tags, see the main documentation for this trait and for class Filter.
Note that this means that even if a test is marked as ignored, for example a test method in a Suite annotated with
org.scalatest.Ignore, if that test name is passed as testName to runTest, it will be invoked
despite the Ignore annotation.
If testName is None, this trait's implementation of this method
invokes testNames on this Suite to get a Set of names of tests to potentially run.
(A testNames value of None essentially acts as a wildcard that means all tests in
this Suite that are selected by tagsToInclude and tagsToExclude should be run.)
For each test in the testName Set, in the order
they appear in the iterator obtained by invoking the elements method on the Set, this trait's implementation
of this method checks whether the test should be run based on the Filter.
If so, this implementation invokes runTest, passing in:
testName - the String name of the test to run (which will be one of the names in the testNames Set)reporter - the Reporter passed to this method, or one that wraps and delegates to itstopper - the Stopper passed to this method, or one that wraps and delegates to itconfigMap - the configMap passed to this method, or one that wraps and delegates to itIf a test is marked with the org.scalatest.Ignore tag, implementations
of this method are responsible for ensuring a TestIgnored event is fired for that test
and that runTest is not called for that test.
an optional name of one test to run. If None, all relevant tests should be run.
I.e., None acts like a wildcard that means run all relevant tests in this Suite.
the Reporter to which results will be reported
the Stopper that will be consulted to determine whether to stop execution early.
a Filter with which to filter tests based on their tags
a Map of key-value pairs that can be used by the executing Suite of tests.
an optional Distributor, into which to put nested Suites to be run
by another entity, such as concurrently by a pool of threads. If None, nested Suites will be run sequentially.
a Tracker tracking Ordinals being fired by the current thread.
A user-friendly suite name for this Suite.
A user-friendly suite name for this Suite.
This trait's
implementation of this method returns the simple name of this object's class. This
trait's implementation of runNestedSuites calls this method to obtain a
name for Reports to pass to the suiteStarting, suiteCompleted,
and suiteAborted methods of the Reporter.
this Suite object's suite name.
A Map whose keys are String tag names with which tests in this Suite are marked, and
whose values are the Set of test names marked with each tag.
A Map whose keys are String tag names with which tests in this Suite are marked, and
whose values are the Set of test names marked with each tag. If this Suite contains no tags, this
method returns an empty Map.
This trait's implementation of this method uses Java reflection to discover any Java annotations attached to its test methods. The
fully qualified name of each unique annotation that extends TagAnnotation is considered a tag. This trait's
implementation of this method, therefore, places one key/value pair into to the
Map for each unique tag annotation name discovered through reflection. The mapped value for each tag name key will contain
the test method name, as provided via the testNames method.
Subclasses may override this method to define and/or discover tags in a custom manner, but overriding method implementations
should never return an empty Set as a value. If a tag has no tests, its name should not appear as a key in the
returned Map.
Note, the TagAnnotation annotation was introduced in ScalaTest 1.0, when "groups" were renamed
to "tags." In 1.0 and 1.1, the TagAnnotation will continue to not be required by an annotation on a Suite
method. Any annotation on a Suite method will be considered a tag until 1.2, to give users time to add
TagAnnotations on any tag annotations they made prior to the 1.0 release. From 1.2 onward, only annotations
themselves annotated by TagAnnotation will be considered tag annotations.
An Set of test names.
An Set of test names. If this Suite contains no tests, this method returns an empty Set.
This trait's implementation of this method uses Java reflection to discover all public methods whose name starts with "test",
which take either nothing or a single Informer as parameters. For each discovered test method, it assigns a test name
comprised of just the method name if the method takes no parameters, or the method name plus (Informer) if the
method takes a Informer. Here are a few method signatures and the names that this trait's implementation assigns them:
def testCat() {} // test name: "testCat"
def testCat(Informer) {} // test name: "testCat(Informer)"
def testDog() {} // test name: "testDog"
def testDog(Informer) {} // test name: "testDog(Informer)"
def test() {} // test name: "test"
def test(Informer) {} // test name: "test(Informer)"
This trait's implementation of this method returns an immutable Set of all such names, excluding the name
testNames. The iterator obtained by invoking elements on this
returned Set will produce the test names in their natural order, as determined by String's
compareTo method.
This trait's implementation of runTests invokes this method
and calls runTest for each test name in the order they appear in the returned Set's iterator.
Although this trait's implementation of this method returns a Set whose iterator produces String
test names in a well-defined order, the contract of this method does not required a defined order. Subclasses are free to
override this method and return test names in an undefined order, or in a defined order that's different from String's
natural order.
Subclasses may override this method to produce test names in a custom manner. One potential reason to override testNames is
to run tests in a different order, for example, to ensure that tests that depend on other tests are run after those other tests.
Another potential reason to override is allow tests to be defined in a different manner, such as methods annotated @Test annotations
(as is done in JUnitSuite and TestNGSuite) or test functions registered during construction (as is
done in FunSuite and Spec).
Executes the block of code passed as the second parameter, and, if it
completes abruptly with a ModifiableMessage exception,
prepends the "clue" string passed as the first parameter to the beginning of the detail message
of that thrown exception, then rethrows it.
Executes the block of code passed as the second parameter, and, if it
completes abruptly with a ModifiableMessage exception,
prepends the "clue" string passed as the first parameter to the beginning of the detail message
of that thrown exception, then rethrows it. If clue does not end in a white space
character, one space will be added
between it and the existing detail message (unless the detail message is
not defined).
This method allows you to add more information about what went wrong that will be reported when a test fails. Here's an example:
withClue("(Employee's name was: " + employee.name + ")") {
intercept[IllegalArgumentException] {
employee.getTask(-1)
}
}
If an invocation of intercept completed abruptly with an exception, the resulting message would be something like:
(Employee's name was Bob Jones) Expected IllegalArgumentException to be thrown, but no exception was thrown
Run the passed test function in the context of a fixture established by this method.
Run the passed test function in the context of a fixture established by this method.
This method should set up the fixture needed by the tests of the
current suite, invoke the test function, and if needed, perform any clean
up needed after the test completes. Because the NoArgTest function
passed to this method takes no parameters, preparing the fixture will require
side effects, such as reassigning instance vars in this Suite or initializing
a globally accessible external database. If you want to avoid reassigning instance vars
you can use FixtureSuite.
This trait's implementation of runTest invokes this method for each test, passing
in a NoArgTest whose apply method will execute the code of the test.
This trait's implementation of this method simply invokes the passed NoArgTest function.
the no-arg test function to run with a fixture
The groups methods has been deprecated and will be removed in a future version of ScalaTest.
Please call (and override) tags instead.
The groups methods has been deprecated and will be removed in a future version of ScalaTest.
Please call (and override) tags instead.
scala.this.deprecated.init$default$1
A suite of tests. A
Suiteinstance encapsulates a conceptual suite (i.e., a collection) of tests.This trait provides an interface that allows suites of tests to be run. Its implementation enables a default way of writing and executing tests. Subtraits and subclasses can override
Suite's methods to enable other ways of writing and executing tests. This trait's default approach allows tests to be defined as methods whose name starts with "test." This approach is easy to understand, and a good way for Scala beginners to start writing tests. More advanced Scala programmers may prefer to mix together otherSuitesubtraits defined in ScalaTest, or create their own, to write tests in the way they feel makes them most productive. Here's a quick overview of some of the options to help you get started:For JUnit 3 users
If you are using JUnit 3 (version 3.8 or earlier releases) and you want to write JUnit 3 tests in Scala, look at
AssertionsForJUnit,ShouldMatchersForJUnit, andJUnit3Suite.For JUnit 4 users
If you are using JUnit 4 and you want to write JUnit 4 tests in Scala, look at
JUnitSuite, andJUnitRunner. WithJUnitRunner, you can use any of the traits described here and still run your tests with JUnit 4.For TestNG users
If you are using TestNG and you want to write TestNG tests in Scala, look at
TestNGSuite.For high-level testing
If you want to write tests at a higher level than unit tests, such as integration tests, acceptance tests, or functional tests, check out
FeatureSpec.For unit testing
If you prefer a behavior-driven development (BDD) style, in which tests are combined with text that specifies the behavior being tested, look at
Spec,FlatSpec, andWordSpec. Otherwise, if you just want to write tests and don't want to combine testing with specifying, look atFunSuiteor read on to learn how to write tests using this base trait,Suite.To use this trait's approach to writing tests, simply create classes that extend
Suiteand define test methods. Test methods have names of the formtestX, whereXis some unique, hopefully meaningful, string. A test method must be public and can have any result type, but the most common result type isUnit. Here's an example:import org.scalatest.Suite class MySuite extends Suite { def testAddition() { val sum = 1 + 1 assert(sum === 2) assert(sum + 2 === 4) } def testSubtraction() { val diff = 4 - 1 assert(diff === 3) assert(diff - 2 === 1) } }You can run a
Suiteby invoking on it one of four overloadedexecutemethods. These methods, which print test results to the standard output, are intended to serve as a convenient way to run tests from within the Scala interpreter. For example, to runMySuitefrom within the Scala interpreter, you could write:And you would see:
Or, to run just the
testAdditionmethod, you could write:scala> (new MySuite).execute("testAddition")And you would see:
Two other
executemethods that are intended to be run from the interpreter accept a "config" map of key-value pairs (see Config map, below). Each of theseexecutemethods invokes arunmethod takes seven parameters. Thisrunmethod, which actually executes the suite, will usually be invoked by a test runner, such asorg.scalatest.tools.Runneror an IDE. See the documentation forRunnerfor more detail.Assertions and
Inside test methods in a
Suite, you can write assertions by invokingassertand passing in aBooleanexpression, such as:If the passed expression is
true,assertwill return normally. Iffalse,assertwill complete abruptly with aTestFailedException. This exception is usually not caught by the test method, which means the test method itself will complete abruptly by throwing theTestFailedException. Any test method that completes abruptly with aTestFailedExceptionor anyExceptionis considered a failed test. A test method that returns normally is considered a successful test.If you pass a
Booleanexpression toassert, a failed assertion will be reported, but without reporting the left and right values. You can alternatively encode these values in aStringpassed as a second argument toassert, as in:Using this form of
assert, the failure report will include the left and right values, thereby helping you debug the problem. However, ScalaTest provides the===operator to make this easier. (The===operator is defined in traitAssertionswhich traitSuiteextends.) You use it like this:Because you use
===here instead of==, the failure report will include the left and right values. For example, the detail message in the thrownTestFailedExceptionfrom theassertshown previously will include, "2 did not equal 1". From this message you will know that the operand on the left had the value 2, and the operand on the right had the value 1.If you're familiar with JUnit, you would use
===in a ScalaTestSuitewhere you'd useassertEqualsin a JUnitTestCase. The===operator is made possible by an implicit conversion fromAnytoEqualizer. If you're curious to understand the mechanics, see the documentation forEqualizerand theconvertToEqualizermethod.Expected results
Although
===provides a natural, readable extension to Scala'sassertmechanism, as the operands become lengthy, the code becomes less readable. In addition, the===comparison doesn't distinguish between actual and expected values. The operands are just calledleftandright, because if one were namedexpectedand the otheractual, it would be difficult for people to remember which was which. To help with these limitations of assertions,Suiteincludes a method calledexpectthat can be used as an alternative toassertwith===. To useexpect, you place the expected value in parentheses afterexpect, followed by curly braces containing code that should result in the expected value. For example:val a = 5 val b = 2 expect(2) { a - b }In this case, the expected value is
2, and the code being tested isa - b. This expectation will fail, and the detail message in theTestFailedExceptionwill read, "Expected 2, but got 3."Intercepted exceptions
Sometimes you need to test whether a method throws an expected exception under certain circumstances, such as when invalid arguments are passed to the method. You can do this in the JUnit style, like this:
val s = "hi" try { s.charAt(-1) fail() } catch { case _: IndexOutOfBoundsException => // Expected, so continue }If
charAtthrowsIndexOutOfBoundsExceptionas expected, control will transfer to the catch case, which does nothing. If, however,charAtfails to throw an exception, the next statement,fail(), will be executed. Thefailmethod always completes abruptly with aTestFailedException, thereby signaling a failed test.To make this common use case easier to express and read, ScalaTest provides an
interceptmethod. You use it like this:val s = "hi" intercept[IndexOutOfBoundsException] { s.charAt(-1) }This code behaves much like the previous example. If
charAtthrows an instance ofIndexOutOfBoundsException,interceptwill return that exception. But ifcharAtcompletes normally, or throws a different exception,interceptwill complete abruptly with aTestFailedException. Theinterceptmethod returns the caught exception so that you can inspect it further if you wish, for example, to ensure that data contained inside the exception has the expected values. Here's an example:val s = "hi" val caught = intercept[IndexOutOfBoundsException] { s.charAt(-1) } assert(caught.getMessage === "String index out of range: -1")Using other assertions
ScalaTest also supports another style of assertions via its matchers DSL. By mixing in trait
ShouldMatchers, you can write suites that look like:import org.scalatest.Suite import org.scalatest.matchers.ShouldMatchers class MySuite extends Suite with ShouldMatchers { def testAddition() { val sum = 1 + 1 sum should equal (2) sum + 2 should equal (4) } def testSubtraction() { val diff = 4 - 1 diff should equal (3) diff - 2 should equal (1) } }If you prefer the word "
must" to the word "should," you can alternatively mix in traitMustMatchers.If you are comfortable with assertion mechanisms from other test frameworks, chances are you can use them with ScalaTest. Any assertion mechanism that indicates a failure with an exception can be used as is with ScalaTest. For example, to use the
assertEqualsmethods provided by JUnit or TestNG, simply import them and use them. (You will of course need to include the relevant JAR file for the framework whose assertions you want to use on either the classpath or runpath when you run your tests.) Here's an example in which JUnit's assertions are imported, then used within a ScalaTest suite:import org.scalatest.Suite import org.junit.Assert._ class MySuite extends Suite { def testAddition() { val sum = 1 + 1 assertEquals(2, sum) assertEquals(4, sum + 2) } def testSubtraction() { val diff = 4 - 1 assertEquals(3, diff) assertEquals(1, diff - 2) } }Nested suites
A
Suitecan refer to a collection of otherSuites, which are called nestedSuites. Those nestedSuites can in turn have their own nestedSuites, and so on. Large test suites can be organized, therefore, as a tree of nestedSuites. This trait'srunmethod, in addition to invoking its test methods, invokesrunon each of its nestedSuites.A
Listof aSuite's nestedSuites can be obtained by invoking itsnestedSuitesmethod. If you wish to create aSuitethat serves as a container for nestedSuites, whether or not it has test methods of its own, simply overridenestedSuitesto return aListof the nestedSuites. Because this is a common use case, ScalaTest provides a convenienceSuperSuiteclass, which takes aListof nestedSuites as a constructor parameter. Here's an example:import org.scalatest.Suite class ASuite extends Suite class BSuite extends Suite class CSuite extends Suite class AlphabetSuite extends SuperSuite( List( new ASuite, new BSuite, new CSuite ) )If you now run
AlphabetSuite, for example from the interpreter:You will see reports printed to the standard output that indicate nested suites—
ASuite,BSuite, andCSuite—were run.Note that
Runnercan discoverSuites automatically, so you need not necessarily specifySuperSuites explicitly. See the documentation forRunnerfor more information.Shared fixtures
A test fixture is objects or other artifacts (such as files, sockets, database connections, etc.) used by tests to do their work. If a fixture is used by only one test method, then the definitions of the fixture objects can be local to the method, such as the objects assigned to
sumanddiffin the previousMySuiteexamples. If multiple methods need to share an immutable fixture, one approach is to assign them to instance variables. Here's a (very contrived) example, in which the object assigned tosharedis used by multiple test methods:import org.scalatest.Suite class MySuite extends Suite { // Sharing immutable fixture objects via instance variables val shared = 5 def testAddition() { val sum = 2 + 3 assert(sum === shared) } def testSubtraction() { val diff = 7 - 2 assert(diff === shared) } }In some cases, however, shared mutable fixture objects may be changed by test methods such that they need to be recreated or reinitialized before each test. Shared resources such as files or database connections may also need to be created and initialized before, and cleaned up after, each test. JUnit 3 offers methods
setUpandtearDownfor this purpose. In ScalaTest, you can use theBeforeAndAfterEachtrait, which will be described later, to implement an approach similar to JUnit'ssetUpandtearDown, however, this approach usually involves reassigningvars between tests. Before going that route, you may wish to consider some approaches that avoidvars. One approach is to write one or more create-fixture methods that return a new instance of a needed object (or a tuple or case class holding new instances of multiple objects) each time it is called. You can then call a create-fixture method at the beginning of each test method that needs the fixture, storing the fixture object or objects in local variables. Here's an example:import org.scalatest.Suite import scala.collection.mutable.ListBuffer class MySuite extends Suite { // create objects needed by tests and return as a tuple def createFixture = ( new StringBuilder("ScalaTest is "), new ListBuffer[String] ) def testEasy() { val (builder, lbuf) = createFixture builder.append("easy!") assert(builder.toString === "ScalaTest is easy!") assert(lbuf.isEmpty) lbuf += "sweet" } def testFun() { val (builder, lbuf) = createFixture builder.append("fun!") assert(builder.toString === "ScalaTest is fun!") assert(lbuf.isEmpty) } }If different tests in the same
Suiterequire different fixtures, you can create multiple create-fixture methods and call the method (or methods) needed by each test at the begining of the test. If every test method requires the same set of mutable fixture objects, one other approach you can take is make them simplyvals and mix in traitOneInstancePerTest. If you mix inOneInstancePerTest, each test will be run in its own instance of theSuite, similar to the way JUnit tests are executed.Although the create-fixture and
OneInstancePerTestapproaches take care of setting up a fixture before each test, they don't address the problem of cleaning up a fixture after the test completes. In this situation, one option is to mix in theBeforeAndAfterEachtrait.BeforeAndAfterEach'sbeforeEachmethod will be run before, and itsafterEachmethod after, each test (like JUnit'ssetUpandtearDownmethods, respectively). For example, you could create a temporary file before each test, and delete it afterwords, like this:import org.scalatest.Suite import org.scalatest.BeforeAndAfterEach import java.io.FileReader import java.io.FileWriter import java.io.File class MySuite extends Suite with BeforeAndAfterEach { private val FileName = "TempFile.txt" private var reader: FileReader = _ // Set up the temp file needed by the test override def beforeEach() { val writer = new FileWriter(FileName) try { writer.write("Hello, test!") } finally { writer.close() } // Create the reader needed by the test reader = new FileReader(FileName) } // Close and delete the temp file override def afterEach() { reader.close() val file = new File(FileName) file.delete() } def testReadingFromTheTempFile() { var builder = new StringBuilder var c = reader.read() while (c != -1) { builder.append(c.toChar) c = reader.read() } assert(builder.toString === "Hello, test!") } def testFirstCharOfTheTempFile() { assert(reader.read() === 'H') } def testWithoutAFixture() { assert(1 + 1 === 2) } }In this example, the instance variable
readeris avar, so it can be reinitialized between tests by thebeforeEachmethod.Although the
BeforeAndAfterEachapproach should be familiar to the users of most test other frameworks, ScalaTest provides another alternative that also allows you to perform cleanup after each test: overridingwithFixture(NoArgTest). To execute each test,Suite's implementation of therunTestmethod wraps an invocation of the appropriate test method in a no-arg function.runTestpasses that test function to thewithFixture(NoArgTest)method, which is responsible for actually running the test by invoking the function.Suite's implementation ofwithFixture(NoArgTest)simply invokes the function, like this:// Default implementation protected def withFixture(test: NoArgTest) { test() }The
withFixture(NoArgTest)method exists so that you can override it and set a fixture up before, and clean it up after, each test. Thus, the previous temp file example could also be implemented without mixing inBeforeAndAfterEach, like this:import org.scalatest.Suite import java.io.FileReader import java.io.FileWriter import java.io.File class MySuite extends Suite { private var reader: FileReader = _ override def withFixture(test: NoArgTest) { val FileName = "TempFile.txt" // Set up the temp file needed by the test val writer = new FileWriter(FileName) try { writer.write("Hello, test!") } finally { writer.close() } // Create the reader needed by the test reader = new FileReader(FileName) try { test() // Invoke the test function } finally { // Close and delete the temp file reader.close() val file = new File(FileName) file.delete() } } def testReadingFromTheTempFile() { var builder = new StringBuilder var c = reader.read() while (c != -1) { builder.append(c.toChar) c = reader.read() } assert(builder.toString === "Hello, test!") } def testFirstCharOfTheTempFile() { assert(reader.read() === 'H') } def testWithoutAFixture() { assert(1 + 1 === 2) } }If you prefer to keep your test classes immutable, one final variation is to use the
FixtureSuitetrait from theorg.scalatest.fixturepackage. Tests in anorg.scalatest.fixture.FixtureSuitecan have a fixture object passed in as a parameter. You must indicate the type of the fixture object by defining theFixturetype member and define awithFixturemethod that takes a one-arg test function. (AFixtureSuitehas two overloadedwithFixturemethods, therefore, one that takes aOneArgTestand the other, inherited fromSuite, that takes aNoArgTest.) Inside thewithFixture(OneArgTest)method, you create the fixture, pass it into the test function, then perform any necessary cleanup after the test function returns. Instead of invoking each test directly, aFixtureSuitewill pass a function that invokes the code of a test towithFixture(OneArgTest). YourwithFixture(OneArgTest)method, therefore, is responsible for actually running the code of the test by invoking the test function. For example, you could pass the temp file reader fixture to each test that needs it by overriding thewithFixture(OneArgTest)method of aFixtureSuite, like this:import org.scalatest.fixture.FixtureSuite import java.io.FileReader import java.io.FileWriter import java.io.File class MySuite extends FixtureSuite { // No vars needed in this one type FixtureParam = FileReader def withFixture(test: OneArgTest) { val FileName = "TempFile.txt" // Set up the temp file needed by the test val writer = new FileWriter(FileName) try { writer.write("Hello, test!") } finally { writer.close() } // Create the reader needed by the test val reader = new FileReader(FileName) try { // Run the test, passing in the temp file reader test(reader) } finally { // Close and delete the temp file reader.close() val file = new File(FileName) file.delete() } } def testReadingFromTheTempFile(reader: FileReader) { var builder = new StringBuilder var c = reader.read() while (c != -1) { builder.append(c.toChar) c = reader.read() } assert(builder.toString === "Hello, test!") } def testFirstCharOfTheTempFile(reader: FileReader) { assert(reader.read() === 'H') } def testWithoutAFixture() { assert(1 + 1 === 2) } }It is worth noting that the only difference in the test code between the mutable
BeforeAndAfterEachapproach shown previously and the immutableFixtureSuiteapproach shown here is that two of theFixtureSuite's test methods take aFileReaderas a parameter. Otherwise the test code is identical. One benefit of the explicit parameter is that, as demonstrated by thetestWithoutAFixturemethod, aFixtureSuitetest method need not take the fixture. (Tests that don't take a fixture as a parameter are passed to thewithFixturethat takes aNoArgTest, shown previously.) So you can have some tests that take a fixture, and others that don't. In this case, theFixtureSuiteprovides documentation indicating which test methods use the fixture and which don't, whereas theBeforeAndAfterEachapproach does not.If you want to execute code before and after all tests (and nested suites) in a suite, such as you could do with
@BeforeClassand@AfterClassannotations in JUnit 4, you can use thebeforeAllandafterAllmethods ofBeforeAndAfterAll. See the documentation forBeforeAndAfterAllfor an example.The config map
In some cases you may need to pass information to a suite of tests. For example, perhaps a suite of tests needs to grab information from a file, and you want to be able to specify a different filename during different runs. You can accomplish this in ScalaTest by passing the filename in the config map of key-value pairs, which is passed to
runas aMap[String, Any]. The values in the config map are called "config objects," because they can be used to configure suites, reporters, and tests.You can specify a string config object is via the ScalaTest
Runner, either via the command line or ScalaTest's ant task. (See the documentation for Runner for information on how to specify config objects on the command line.) The config map is passed torun,runNestedSuites,runTests, andrunTest, so one way to access it in your suite is to override one of those methods. If you need to use the config map inside your tests, you can use one of the traits in theorg.scalatest.fixturepackage. (See the documentation forFixtureSuitefor instructions on how to access the config map in tests.)Tagging tests
A
Suite's tests may be classified into groups by tagging them with string names. When executing aSuite, groups of tests can optionally be included and/or excluded. In this trait's implementation, tags are indicated by annotations attached to the test method. To create a new tag type to use inSuites, simply define a new Java annotation that itself is annotated with theorg.scalatest.TagAnnotationannotation. (Currently, for annotations to be visible in Scala programs via Java reflection, the annotations themselves must be written in Java.) For example, to create a tag namedSlowAsMolasses, to use to mark slow tests, you would write in Java:BECAUSE OF A SCALADOC BUG IN SCALA 2.8, I HAD TO PUT A SPACE AFTER THE AT SIGN IN ONE THE TARGET ANNOTATION EXAMPLE BELOW. IF YOU WANT TO COPY AND PASTE FROM THIS EXAMPLE, YOU'LL NEED TO REMOVE THE SPACE BY HAND, OR COPY FROM THE SUITE SCALADOC FOR VERSION 1.1 INSTEAD, WHICH IS ALSO VALID FOR 1.3. - Bill Venners
import java.lang.annotation.*; import org.scalatest.TagAnnotation @TagAnnotation @Retention(RetentionPolicy.RUNTIME) @ Target({ElementType.METHOD, ElementType.TYPE}) public @interface SlowAsMolasses {}Given this new annotation, you could place a
Suitetest method into theSlowAsMolassesgroup (i.e., tag it as beingSlowAsMolasses) like this:The primary
runmethod takes aFilter, whose constructor takes an optionalSet[String]s calledtagsToIncludeand aSet[String]calledtagsToExclude. IftagsToIncludeisNone, all tests will be run except those those belonging to tags listed in thetagsToExcludeSet. IftagsToIncludeis defined, only tests belonging to tags mentioned in thetagsToIncludeset, and not mentioned intagsToExclude, will be run.Ignored tests
Another common use case is that tests must be “temporarily” disabled, with the good intention of resurrecting the test at a later time. ScalaTest provides an
Ignoreannotation for this purpose. You use it like this:import org.scalatest.Suite import org.scalatest.Ignore class MySuite extends Suite { def testAddition() { val sum = 1 + 1 assert(sum === 2) assert(sum + 2 === 4) } @Ignore def testSubtraction() { val diff = 4 - 1 assert(diff === 3) assert(diff - 2 === 1) } }If you run this version of
MySuitewith:It will run only
testAdditionand report thattestSubtractionwas ignored. You'll see:Ignoreis implemented as a tag. TheFilterclass effectively addsorg.scalatest.Ignoreto thetagsToExcludeSetif it not already in thetagsToExcludeset passed to its primary constructor. The only difference betweenorg.scalatest.Ignoreand the tags you may define and exclude is that ScalaTest reports ignored tests to theReporter. The reason ScalaTest reports ignored tests is as a feeble attempt to encourage ignored tests to be eventually fixed and added back into the active suite of tests.Pending tests
A pending test is one that has been given a name but is not yet implemented. The purpose of pending tests is to facilitate a style of testing in which documentation of behavior is sketched out before tests are written to verify that behavior (and often, the before the behavior of the system being tested is itself implemented). Such sketches form a kind of specification of what tests and functionality to implement later.
To support this style of testing, a test can be given a name that specifies one bit of behavior required by the system being tested. The test can also include some code that sends more information about the behavior to the reporter when the tests run. At the end of the test, it can call method
pending, which will cause it to complete abruptly withTestPendingException. Because tests in ScalaTest can be designated as pending withTestPendingException, both the test name and any information sent to the reporter when running the test can appear in the report of a test run. (In other words, the code of a pending test is executed just like any other test.) However, because the test completes abruptly withTestPendingException, the test will be reported as pending, to indicate the actual test, and possibly the functionality it is intended to test, has not yet been implemented.Although pending tests may be used more often in specification-style suites, such as
org.scalatest.Spec, you can also use it inSuite, like this:import org.scalatest.Suite class MySuite extends Suite { def testAddition() { val sum = 1 + 1 assert(sum === 2) assert(sum + 2 === 4) } def testSubtraction() { pending } }If you run this version of
MySuitewith:It will run both tests but report that
testSubtractionis pending. You'll see:Informers
One of the parameters to the primary
runmethod is anReporter, which will collect and report information about the running suite of tests. Information about suites and tests that were run, whether tests succeeded or failed, and tests that were ignored will be passed to theReporteras the suite runs. Most often the reporting done by default bySuite's methods will be sufficient, but occasionally you may wish to provide custom information to theReporterfrom a test method. For this purpose, you can optionally include anInformerparameter in a test method, and then pass the extra information to theInformervia itsapplymethod. TheInformerwill then pass the information to theReporterby sending anInfoProvidedevent. Here's an example:import org.scalatest._ class MySuite extends Suite { def testAddition(info: Informer) { assert(1 + 1 === 2) info("Addition seems to work") } }If you run this
Suitefrom the interpreter, you will see the message included in the printed report:Executing suites in parallel
The primary
runmethod takes as its last parameter an optionalDistributor. If aDistributoris passed in, this trait's implementation ofrunputs its nestedSuites into the distributor rather than executing them directly. The caller ofrunis responsible for ensuring that some entity runs theSuites placed into the distributor. The-ccommand line parameter toRunner, for example, will causeSuites put into theDistributorto be run in parallel via a pool of threads.Treatement of
java.lang.ErrorsThe Javadoc documentation for
java.lang.Errorstates:Because
Errors are used to denote serious errors, traitSuiteand its subtypes in the ScalaTest API do not always treat a test that completes abruptly with anErroras a test failure, but sometimes as an indication that serious problems have arisen that should cause the run to abort. For example, if a test completes abruptly with anOutOfMemoryError, it will not be reported as a test failure, but will instead cause the run to abort. Because not everyone usesErrors only to represent serious problems, however, ScalaTest only behaves this way for the following exception types (and their subclasses):java.lang.annotation.AnnotationFormatErrorjava.awt.AWTErrorjava.nio.charset.CoderMalfunctionErrorjavax.xml.parsers.FactoryConfigurationErrorjava.lang.LinkageErrorjava.lang.ThreadDeathjavax.xml.transform.TransformerFactoryConfigurationErrorjava.lang.VirtualMachineErrorThe previous list includes all
Errors that exist as part of Java 1.5 API, excludingjava.lang.AssertionError. ScalaTest does treat a thrownAssertionErroras an indication of a test failure. In addition, any otherErrorthat is not an instance of a type mentioned in the previous list will be caught by theSuitetraits in the ScalaTest API and reported as the cause of a test failure.Although trait
Suiteand all its subtypes in the ScalaTest API consistently behave this way with regard toErrors, this behavior is not required by the contract ofSuite. Subclasses and subtraits that you define, for example, may treat allErrors as test failures, or indicate errors in some other way that has nothing to do with exceptions.Extensibility
Trait
Suiteprovides default implementations of its methods that should be sufficient for most applications, but many methods can be overridden when desired. Here's a summary of the methods that are intended to be overridden:run- override this method to define custom ways to run suites of tests.runNestedSuites- override this method to define custom ways to run nested suites.runTests- override this method to define custom ways to run a suite's tests.runTest- override this method to define custom ways to run a single named test.testNames- override this method to specify theSuite's test names in a custom way.tags- override this method to specify theSuite's test tags in a custom way.nestedSuites- override this method to specify theSuite's nestedSuites in a custom way.suiteName- override this method to specify theSuite's name in a custom way.expectedTestCount- override this method to count thisSuite's expected tests in a custom way.For example, this trait's implementation of
testNamesperforms reflection to discover methods starting withtest, and places these in aSetwhose iterator returns the names in alphabetical order. If you wish to run tests in a different order in a particularSuite, perhaps because a test namedtestAlphacan only succeed after a test namedtestBetahas run, you can overridetestNamesso that it returns aSetwhose iterator returnstestBetabeforetestAlpha. (This trait's implementation ofrunwill invoke tests in the order they come out of thetestNamesSetiterator.)Alternatively, you may not like starting your test methods with
test, and prefer using@Testannotations in the style of Java's JUnit 4 or TestNG. If so, you can overridetestNamesto discover tests using either of these two APIs@Testannotations, or one of your own invention. (This is in fact howorg.scalatest.junit.JUnitSuiteandorg.scalatest.testng.TestNGSuitework.)Moreover, test in ScalaTest does not necessarily mean test method. A test can be anything that can be given a name, that starts and either succeeds or fails, and can be ignored. In
org.scalatest.FunSuite, for example, tests are represented as function values. This approach might look foreign to JUnit users, but may feel more natural to programmers with a functional programming background. To facilitate this style of writing tests,FunSuiteoverridestestNames,runTest, andrunsuch that you can define tests as function values.You can also model existing JUnit 3, JUnit 4, or TestNG tests as suites of tests, thereby incorporating tests written in Java into a ScalaTest suite. The "wrapper" classes in packages
org.scalatest.junitandorg.scalatest.testngexist to make this easy. No matter what legacy tests you may have, it is likely you can create or use an existingSuitesubclass that allows you to model those tests as ScalaTest suites and tests and incorporate them into a ScalaTest suite. You can then write new tests in Scala and continue supporting older tests in Java.