org.scalatest

BeforeAndAfter

trait BeforeAndAfter extends SuiteMixin

Trait that can be mixed into suites that need code executed before and after running each test.

Recommended Usage: Use trait BeforeAndAfter when you need to perform the same side-effects before and/or after tests, rather than at the beginning or end of tests. Note: For more insight into where BeforeAndAfter fits into the big picture, see the Shared fixtures section in the documentation for your chosen style trait.

A test fixture is composed of the objects and other artifacts (files, sockets, database connections, etc.) tests use to do their work. When multiple tests need to work with the same fixtures, it is important to try and avoid duplicating the fixture code across those tests. The more code duplication you have in your tests, the greater drag the tests will have on refactoring the actual production code. Trait BeforeAndAfter offers one way to eliminate such code duplication: a before clause that will register code to be run before each test, and an after clause that will register code to be run after.

Here's an example:

package org.scalatest.examples.flatspec.beforeandafter

import org.scalatest._ import collection.mutable.ListBuffer
class ExampleSpec extends FlatSpec with BeforeAndAfter {
val builder = new StringBuilder val buffer = new ListBuffer[String]
before { builder.append("ScalaTest is ") }
after { builder.clear() buffer.clear() }
"Testing" should "be easy" in { builder.append("easy!") assert(builder.toString === "ScalaTest is easy!") assert(buffer.isEmpty) buffer += "sweet" }
it should "be fun" in { builder.append("fun!") assert(builder.toString === "ScalaTest is fun!") assert(buffer.isEmpty) } }

The before and after methods can each only be called once per Suite, and cannot be invoked after run has been invoked. If either of the registered before or after functions complete abruptly with an exception, it will be reported as an aborted suite and no more tests will be attempted in that suite.

Note that the only way before and after code can communicate with test code is via some side-effecting mechanism, commonly by reassigning instance vars or by changing the state of mutable objects held from instance vals (as in this example). If using instance vars or mutable objects held from instance vals you wouldn't be able to run tests in parallel in the same instance of the test class unless you synchronized access to the shared, mutable state. This is why ScalaTest's ParallelTestExecution trait extends OneInstancePerTest. By running each test in its own instance of the class, each test has its own copy of the instance variables, so you don't need to synchronize. Were you to mix ParallelTestExecution into the ExampleSuite above, the tests would run in parallel just fine without any synchronization needed on the mutable StringBuilder and ListBuffer[String] objects.

Although BeforeAndAfter provides a minimal-boilerplate way to execute code before and after tests, it isn't designed to enable stackable traits, because the order of execution would be non-obvious. If you want to factor out before and after code that is common to multiple test suites, you should use trait BeforeAndAfterEach instead.

The advantage this trait has over BeforeAndAfterEach is that its syntax is more concise. The main disadvantage is that it is not stackable, whereas BeforeAndAfterEach is. I.e., you can write several traits that extend BeforeAndAfterEach and provide beforeEach methods that include a call to super.beforeEach, and mix them together in various combinations. By contrast, only one call to the before registration function is allowed in a suite or spec that mixes in BeforeAndAfter. In addition, BeforeAndAfterEach allows you to access the config map and test name via the TestData passed to its beforeEach and afterEach methods, whereas BeforeAndAfter gives you no access to the config map.

Self Type
BeforeAndAfter with Suite
Linear Supertypes
SuiteMixin, AnyRef, Any
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Abstract Value Members

  1. def expectedTestCount (filter: Filter): Int

    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.

    filter

    a Filter with which to filter tests to count based on their tags

    Attributes
    abstract
    Definition Classes
    SuiteMixin
  2. def nestedSuites : IndexedSeq[Suite]

    An immutable IndexedSeq of this SuiteMixin object's nested Suites.

    An immutable IndexedSeq of this SuiteMixin object's nested Suites. If this SuiteMixin contains no nested Suites, this method returns an empty IndexedSeq.

    Attributes
    abstract
    Definition Classes
    SuiteMixin
  3. def rerunner : Option[String]

    The fully qualified name of the class that can be used to rerun this suite.

    The fully qualified name of the class that can be used to rerun this suite.

    Attributes
    abstract
    Definition Classes
    SuiteMixin
  4. def runNestedSuites (args: Args): Status

    Runs zero to many of this suite's nested suites.

    Runs zero to many of this suite's nested suites.

    args

    the Args for this run

    returns

    a Status object that indicates when all nested suites started by this method have completed, and whether or not a failure occurred.

    Attributes
    protected abstract
    Definition Classes
    SuiteMixin
  5. def runTests (testName: Option[String], args: Args): Status

    Runs zero to many of this suite's tests.

    Runs zero to many of this suite's tests.

    testName

    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.

    args

    the Args for this run

    returns

    a Status object that indicates when all tests started by this method have completed, and whether or not a failure occurred.

    Attributes
    protected abstract
    Definition Classes
    SuiteMixin
  6. val styleName : String

    This suite's style name.

    This suite's style name.

    This lifecycle method provides a string that is used to determine whether this suite object's style is one of the chosen styles for the project.

    Attributes
    abstract
    Definition Classes
    SuiteMixin
  7. def tags : Map[String, Set[String]]

    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.

    Subclasses may implement 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.

    Attributes
    abstract
    Definition Classes
    SuiteMixin
  8. def testNames : Set[String]

    A Set of test names.

    A Set of test names. If this Suite contains no tests, this method returns an empty Set.

    Although subclass and subtrait implementations of this method may return 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 implement this method and return test names in either a defined or undefined order.

    Attributes
    abstract
    Definition Classes
    SuiteMixin
  9. def withFixture (test: NoArgTest): Unit

    Runs the passed test function with a fixture established by this method.

    Runs the passed test function with 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 initializing an external database.

    test

    the no-arg test function to run with a fixture

    Attributes
    protected abstract
    Definition Classes
    SuiteMixin

Concrete Value Members

  1. def != (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  2. def != (arg0: Any): Boolean

    Attributes
    final
    Definition Classes
    Any
  3. def ## (): Int

    Attributes
    final
    Definition Classes
    AnyRef → Any
  4. def == (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  5. def == (arg0: Any): Boolean

    Attributes
    final
    Definition Classes
    Any
  6. def after (fun: ⇒ Any): Unit

    Registers code to be executed after each of this suite's tests.

    Registers code to be executed after each of this suite's tests.

    This trait's implementation of runTest executes the code passed to this method after running each test. Thus the code passed to this method can be used to tear down a test fixture needed by each test.

    Attributes
    protected
  7. def asInstanceOf [T0] : T0

    Attributes
    final
    Definition Classes
    Any
  8. def before (fun: ⇒ Any): Unit

    Registers code to be executed before each of this suite's tests.

    Registers code to be executed before each of this suite's tests.

    This trait's implementation of runTest executes the code passed to this method before running each test. Thus the code passed to this method can be used to set up a test fixture needed by each test.

    Attributes
    protected
  9. def clone (): AnyRef

    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  10. def eq (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  11. def equals (arg0: Any): Boolean

    Definition Classes
    AnyRef → Any
  12. def finalize (): Unit

    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  13. def getClass (): java.lang.Class[_]

    Attributes
    final
    Definition Classes
    AnyRef
  14. def hashCode (): Int

    Definition Classes
    AnyRef → Any
  15. def isInstanceOf [T0] : Boolean

    Attributes
    final
    Definition Classes
    Any
  16. def ne (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  17. def notify (): Unit

    Attributes
    final
    Definition Classes
    AnyRef
  18. def notifyAll (): Unit

    Attributes
    final
    Definition Classes
    AnyRef
  19. def run (testName: Option[String], args: Args): Status

    This trait's implementation of run sets a flag indicating run has been invoked, after which any invocation to before or after will complete abruptly with a NotAllowedException.

    This trait's implementation of run sets a flag indicating run has been invoked, after which any invocation to before or after will complete abruptly with a NotAllowedException.

    testName

    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.

    args

    the Args for this run

    returns

    a Status object that indicates when all tests and nested suites started by this method have completed, and whether or not a failure occurred.

    Definition Classes
    BeforeAndAfterSuiteMixin
  20. def runTest (testName: String, args: Args): Status

    Run a test surrounded by calls to the code passed to before and after, if any.

    Run a test surrounded by calls to the code passed to before and after, if any.

    This trait's implementation of this method ("this method") invokes the function registered with before, if any, before running each test and the function registered with after, if any, after running each test. It runs each test by invoking super.runTest, passing along the five parameters passed to it.

    If any invocation of the function registered with before completes abruptly with an exception, this method will complete abruptly with the same exception. If any call to super.runTest completes abruptly with an exception, this method will complete abruptly with the same exception, however, before doing so, it will invoke the function registered with after, if any. If the function registered with after also completes abruptly with an exception, this method will nevertheless complete abruptly with the exception previously thrown by super.runTest. If super.runTest returns normally, but the function registered with after completes abruptly with an exception, this method will complete abruptly with the exception thrown by the function registered with after.

    testName

    the name of one test to run.

    args

    the Args for this run

    returns

    a Status object that indicates when the test started by this method has completed, and whether or not it failed .

    Attributes
    protected
    Definition Classes
    BeforeAndAfterSuiteMixin
  21. def synchronized [T0] (arg0: ⇒ T0): T0

    Attributes
    final
    Definition Classes
    AnyRef
  22. def toString (): String

    Definition Classes
    AnyRef → Any
  23. def wait (): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  24. def wait (arg0: Long, arg1: Int): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  25. def wait (arg0: Long): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()

Inherited from SuiteMixin

Inherited from AnyRef

Inherited from Any