org.scalatest

# FunSuite

#### trait FunSuite extends Suite

A suite of tests in which each test is represented as a function value. The “`Fun`” in `FunSuite` stands for “function.” Here's an example `FunSuite`:

    import org.scalatest.FunSuite

    class ExampleSuite extends FunSuite {

      test("addition") {
        val sum = 1 + 1
        assert(sum === 2)
      }

      test("subtraction") {
        val diff = 4 - 1
        assert(diff === 3)
      }
    }

“`test`” is a method, defined in `FunSuite`, which will be invoked by the primary constructor of `ExampleSuite`. You specify the name of the test as a string between the parentheses, and the test code itself between curly braces. The test code is a function passed as a by-name parameter to `test`, which registers it for later execution. One benefit of `FunSuite` compared to `Suite` is you need not name all your tests starting with “`test`.” In addition, you can more easily give long names to your tests, because you need not encode them in camel case.

A `FunSuite`'s lifecycle has two phases: the registration phase and the ready phase. It starts in registration phase and enters ready phase the first time `run` is called on it. It then remains in ready phase for the remainder of its lifetime.

Tests can only be registered with the `test` method while the `FunSuite` is in its registration phase. Any attempt to register a test after the `FunSuite` has entered its ready phase, i.e., after `run` has been invoked on the `FunSuite`, will be met with a thrown `TestRegistrationClosedException`. The recommended style of using `FunSuite` is to register tests during object construction as is done in all the examples shown here. If you keep to the recommended style, you should never see a `TestRegistrationClosedException`.

See also: Getting started with `FunSuite`.

#### Ignored tests

To support the common use case of “temporarily” disabling a test, with the good intention of resurrecting the test at a later time, `FunSuite` provides registration methods that start with `ignore` instead of `test`. For example, to temporarily disable the test named `addition`, just change “`test`” into “`ignore`,” like this:

    import org.scalatest.FunSuite

    class ExampleSuite extends FunSuite {

      ignore("addition") {
        val sum = 1 + 1
        assert(sum === 2)
      }

      test("subtraction") {
        val diff = 4 - 1
        assert(diff === 3)
      }
    }

If you run this version of `ExampleSuite` with:

    scala> (new ExampleSuite).execute()

It will run only `subtraction` and report that `addition` was ignored:

    ExampleSuite:
    - addition !!! IGNORED !!!
    - subtraction

#### Informers

One of the parameters to the `run` method is a `Reporter`, 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 the `Reporter` as the suite runs. Most often the reporting done by default by `FunSuite`'s methods will be sufficient, but occasionally you may wish to provide custom information to the `Reporter` from a test. For this purpose, an `Informer` that will forward information to the current `Reporter` is provided via the `info` parameterless method. You can pass the extra information to the `Informer` via one of its `apply` methods. The `Informer` will then pass the information to the `Reporter` via an `InfoProvided` event. Here's an example:

    import org.scalatest.FunSuite

    class ExampleSuite extends FunSuite {

      test("addition") {
        val sum = 1 + 1
        assert(sum === 2)
        assert(sum + 2 === 4)
        info("Addition seems to work")
      }
    }

If you run this `FunSuite` from the interpreter, you will see the following message included in the printed report:

    ExampleSuite:
    - addition
      + Addition seems to work

#### 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, 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, 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 in `FunSuite`, like this:

    import org.scalatest.FunSuite

    class ExampleSuite extends FunSuite {

      test("addition") {
        val sum = 1 + 1
        assert(sum === 2)
        assert(sum + 2 === 4)
      }

      test("subtraction") (pending)
    }

(Note: "`(pending)`" is the body of the test. Thus the test contains just one statement, an invocation of the `pending` method, which throws `TestPendingException`.) If you run this version of `ExampleSuite` with:

    scala> (new ExampleSuite).execute()

It will run both tests, but report that `subtraction` is pending. You'll see:

    ExampleSuite:
    - addition
    - subtraction (pending)

#### Tagging tests

A `FunSuite`'s tests may be classified into groups by tagging them with string names. As with any suite, when executing a `FunSuite`, groups of tests can optionally be included and/or excluded. To tag a `FunSuite`'s tests, you pass objects that extend abstract class `org.scalatest.Tag` to methods that register tests, `test` and `ignore`. Class `Tag` takes one parameter, a string name. If you have created Java annotation interfaces for use as group names in direct subclasses of `org.scalatest.Suite`, then you will probably want to use group names on your `FunSuite`s that match. To do so, simply pass the fully qualified names of the Java interfaces to the `Tag` constructor. For example, if you've defined Java annotation interfaces with fully qualified names, `com.mycompany.tags.SlowTest` and `com.mycompany.tags.DbTest`, then you could create matching groups for `FunSuite`s like this:

    import org.scalatest.Tag

    object SlowTest extends Tag("com.mycompany.tags.SlowTest")
    object DbTest extends Tag("com.mycompany.tags.DbTest")

Given these definitions, you could place `FunSuite` tests into groups like this:

    import org.scalatest.FunSuite

    class ExampleSuite extends FunSuite {

      test("addition", SlowTest) {
        val sum = 1 + 1
        assert(sum === 2)
      }

      test("subtraction", SlowTest, DbTest) {
        val diff = 4 - 1
        assert(diff === 3)
      }
    }

This code marks both tests, "addition" and "subtraction," with the `com.mycompany.tags.SlowTest` tag, and test "subtraction" with the `com.mycompany.tags.DbTest` tag.

The `run` method takes a `Filter`, whose constructor takes an optional `Set[String]` called `tagsToInclude` and a `Set[String]` called `tagsToExclude`. 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 `tagsToExclude`, will be run.

#### 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 `sum` and `diff` in the previous `ExampleSuite` examples. If multiple methods need to share an immutable fixture, one approach is to assign them to instance variables.

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 offered methods `setUp` and `tearDown` for this purpose. In ScalaTest, you can use the `BeforeAndAfterEach` trait, which will be described later, to implement an approach similar to JUnit's `setUp` and `tearDown`, however, this approach usually involves reassigning `var`s or mutating objects between tests. Before going that route, you may wish to consider some more functional approaches that avoid side effects.

###### Calling create-fixture methods

One approach is to write one or more create-fixture methods that return a new instance of a needed fixture object (or an holder object containing multiple needed fixture 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 returned object or objects in local variables. Here's an example:

    import org.scalatest.FunSuite
    import collection.mutable.ListBuffer

    class ExampleSuite extends FunSuite {

      def fixture =
        new {
          val builder = new StringBuilder("ScalaTest is ")
          val buffer = new ListBuffer[String]
        }

      test("easy") {
        val f = fixture
        f.builder.append("easy!")
        assert(f.builder.toString === "ScalaTest is easy!")
        assert(f.buffer.isEmpty)
        f.buffer += "sweet"
      }

      test("fun") {
        val f = fixture
        f.builder.append("fun!")
        assert(f.builder.toString === "ScalaTest is fun!")
        assert(f.buffer.isEmpty)
      }
    }

The “`f.`” in front of each use of a fixture object provides a visual indication of which objects are part of the fixture, but if you prefer, you can import the the members with “`import f._`” and use the names directly.

###### Instantiating fixture traits

A related technique is to place the fixture objects in a fixture trait and run your test code in the context of a new anonymous class instance that mixes in the fixture trait, like this:

    import org.scalatest.FunSuite
    import collection.mutable.ListBuffer

    class ExampleSuite extends FunSuite {

      trait Fixture {
        val builder = new StringBuilder("ScalaTest is ")
        val buffer = new ListBuffer[String]
      }

      test("easy") {
        new Fixture {
          builder.append("easy!")
          assert(builder.toString === "ScalaTest is easy!")
          assert(buffer.isEmpty)
          buffer += "sweet"
        }
      }

      test("fun") {
        new Fixture {
          builder.append("fun!")
          assert(builder.toString === "ScalaTest is fun!")
          assert(buffer.isEmpty)
        }
      }
    }

###### Mixing in `OneInstancePerTest`

If every test method requires the same set of mutable fixture objects, one other approach you can take is make them simply `val`s and mix in trait `OneInstancePerTest`. If you mix in `OneInstancePerTest`, each test will be run in its own instance of the `Suite`, similar to the way JUnit tests are executed. Here's an example:

    import org.scalatest.FunSuite
    import org.scalatest.OneInstancePerTest
    import collection.mutable.ListBuffer

    class ExampleSuite extends FunSuite with OneInstancePerTest {

      val builder = new StringBuilder("ScalaTest is ")
      val buffer = new ListBuffer[String]

      test("easy") {
        builder.append("easy!")
        assert(builder.toString === "ScalaTest is easy!")
        assert(buffer.isEmpty)
        buffer += "sweet"
      }

      test("fun") {
        builder.append("fun!")
        assert(builder.toString === "ScalaTest is fun!")
        assert(buffer.isEmpty)
      }
    }

Although the create-fixture, fixture-trait, and `OneInstancePerTest` approaches 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, you'll need to either use side effects or the loan pattern.

###### Mixing in `BeforeAndAfter`

One way to use side effects is to mix in the `BeforeAndAfter` trait. With this trait you can denote a bit of code to run before each test with `before` and/or after each test each test with `after`, like this:

    import org.scalatest.FunSuite
    import org.scalatest.BeforeAndAfter
    import collection.mutable.ListBuffer

    class ExampleSuite extends FunSuite with BeforeAndAfter {

      val builder = new StringBuilder
      val buffer = new ListBuffer[String]

      before {
        builder.append("ScalaTest is ")
      }

      after {
        builder.clear()
        buffer.clear()
      }

      test("easy") {
        builder.append("easy!")
        assert(builder.toString === "ScalaTest is easy!")
        assert(buffer.isEmpty)
        buffer += "sweet"
      }

      test("fun") {
        builder.append("fun!")
        assert(builder.toString === "ScalaTest is fun!")
        assert(buffer.isEmpty)
      }
    }

###### Overriding `withFixture(NoArgTest)`

An alternate way to take care of setup and cleanup via side effects is to override `withFixture`. Trait `Suite`'s implementation of `runTest`, which is inherited by this trait, passes a no-arg test function to `withFixture`. It is `withFixture`'s responsibility to invoke that test function. `Suite`'s implementation of `withFixture` simply invokes the function, like this:

    // Default implementation
    protected def withFixture(test: NoArgTest) {
      test()
    }

You can, therefore, override `withFixture` to perform setup before, and cleanup after, invoking the test function. If you have cleanup to perform, you should invoke the test function inside a `try` block and perform the cleanup in a `finally` clause. Here's an example:

    import org.scalatest.FunSuite
    import collection.mutable.ListBuffer

    class ExampleSuite extends FunSuite {

      val builder = new StringBuilder
      val buffer = new ListBuffer[String]

      override def withFixture(test: NoArgTest) {
        builder.append("ScalaTest is ") // perform setup
        try {
          test() // invoke the test function
        }
        finally {
          builder.clear() // perform cleanup
          buffer.clear()
        }
      }

      test("easy") {
        builder.append("easy!")
        assert(builder.toString === "ScalaTest is easy!")
        assert(buffer.isEmpty)
        buffer += "sweet"
      }

      test("fun") {
        builder.append("fun!")
        assert(builder.toString === "ScalaTest is fun!")
        assert(buffer.isEmpty)
        buffer += "clear"
      }
    }

Note that the `NoArgTest` passed to `withFixture`, in addition to an `apply` method that executes the test, also includes the test name as well as the config map passed to `runTest`. Thus you can also use the test name and configuration objects in `withFixture`.

The reason you should perform cleanup in a `finally` clause is that `withFixture` is called by `runTest`, which expects an exception to be thrown to indicate a failed test. Thus when you invoke the `test` function inside `withFixture`, it may complete abruptly with an exception. The `finally` clause will ensure the fixture cleanup happens as that exception propagates back up the call stack to `runTest`.

###### Overriding `withFixture(OneArgTest)`

To use the loan pattern, you can extend `FixtureFunSuite` (from the `org.scalatest.fixture` package) instead of `FunSuite`. Each test in a `FixtureFunSuite` takes a fixture as a parameter, allowing you to pass the fixture into the test. You must indicate the type of the fixture parameter by specifying `FixtureParam`, and implement a `withFixture` method that takes a `OneArgTest`. This `withFixture` method is responsible for invoking the one-arg test function, so you can perform fixture set up before, and clean up after, invoking and passing the fixture into the test function. Here's an example:

    import org.scalatest.fixture.FixtureFunSuite
    import java.io.FileWriter
    import java.io.File

    class ExampleSuite extends FixtureFunSuite {

      final val tmpFile = "temp.txt"

      type FixtureParam = FileWriter

      def withFixture(test: OneArgTest) {

        val writer = new FileWriter(tmpFile) // set up the fixture
        try {
          test(writer) // "loan" the fixture to the test
        }
        finally {
          writer.close() // clean up the fixture
        }
      }

      test("easy") { writer =>
        writer.write("Hello, test!")
        writer.flush()
        assert(new File(tmpFile).length === 12)
      }

      test("fun") { writer =>
        writer.write("Hi, test!")
        writer.flush()
        assert(new File(tmpFile).length === 9)
      }
    }

For more information, see the documentation for `FixtureFunSuite`.

#### Providing different fixtures to different tests

If different tests in the same `FunSuite` require different fixtures, you can combine the previous techniques and provide each test with just the fixture or fixtures it needs. Here's an example in which a `StringBuilder` and a `ListBuffer` are provided via fixture traits, and file writer (that requires cleanup) is provided via the loan pattern:

    import java.io.FileWriter
    import java.io.File
    import collection.mutable.ListBuffer
    import org.scalatest.FunSuite

    class ExampleSuite extends FunSuite {

      final val tmpFile = "temp.txt"

      trait Builder {
        val builder = new StringBuilder("ScalaTest is ")
      }

      trait Buffer {
        val buffer = ListBuffer("ScalaTest", "is")
      }

      def withWriter(testCode: FileWriter => Any) {
        val writer = new FileWriter(tmpFile) // set up the fixture
        try {
          testCode(writer) // "loan" the fixture to the test
        }
        finally {
          writer.close() // clean up the fixture
        }
      }

      test("productive") { // This test needs the StringBuilder fixture
        new Builder {
          builder.append("productive!")
          assert(builder.toString === "ScalaTest is productive!")
        }
      }

      test("readable") { // This test needs the ListBuffer[String] fixture
        new Buffer {
          buffer += ("readable!")
          assert(buffer === List("ScalaTest", "is", "readable!"))
        }
      }

      test("friendly") { // This test needs the FileWriter fixture
        withWriter { writer =>
          writer.write("Hello, user!")
          writer.flush()
          assert(new File(tmpFile).length === 12)
        }
      }

      test("clear and concise") { // This test needs the StringBuilder and ListBuffer
        new Builder with Buffer {
          builder.append("clear!")
          buffer += ("concise!")
          assert(builder.toString === "ScalaTest is clear!")
          assert(buffer === List("ScalaTest", "is", "concise!"))
        }
      }

      test("composable") { // This test needs all three fixtures
        new Builder with Buffer {
          builder.append("clear!")
          buffer += ("concise!")
          assert(builder.toString === "ScalaTest is clear!")
          assert(buffer === List("ScalaTest", "is", "concise!"))
          withWriter { writer =>
            writer.write(builder.toString)
            writer.flush()
            assert(new File(tmpFile).length === 19)
          }
        }
      }
    }

In the previous example, `productive` uses only the `StringBuilder` fixture, so it just instantiates a `new Builder`, whereas `readable` uses only the `ListBuffer` fixture, so it just intantiates a `new Buffer`. `friendly` needs just the `FileWriter` fixture, so it invokes `withWriter`, which prepares and passes a `FileWriter` to the test (and takes care of closing it afterwords).

Two tests need multiple fixtures: `clear and concise` needs both the `StringBuilder` and the `ListBuffer`, so it instantiates a class that mixes in both fixture traits with `new Builder with Buffer`. `composable` needs all three fixtures, so in addition to `new Builder with Buffer` it also invokes `withWriter`, wrapping just the of the test code that needs the fixture.

Note that in this case, the loan pattern is being implemented via the `withWriter` method that takes a function, not by overriding `FixtureFunSuite`'s `withFixture(OneArgTest)` method. `FixtureFunSuite` makes the most sense if all (or at least most) tests need the same fixture, whereas in this `Suite` only two tests need the `FileWriter`.

In the previous example, the `withWriter` method passed an object into the tests. Passing fixture objects into tests is generally a good idea when possible, but sometimes a side affect is unavoidable. For example, if you need to initialize a database running on a server across a network, your with-fixture method will likely have nothing to pass. In such cases, simply create a with-fixture method that takes a by-name parameter and performs setup and cleanup via side effects, like this:

    def withDataInDatabase(test: => Any) {
      // initialize the database across the network
      try {
        test // "loan" the initialized database to the test
      }
      finally {
        // clean up the database
      }
    }

You can then use it like:

    def testUserLogsIn {
      withDataInDatabase {
        // test user logging in scenario
      }
    }

#### Composing stackable fixture traits

In larger projects, teams often end up with several different fixtures that test classes need in different combinations, and possibly initialized (and cleaned up) in different orders. A good way to accomplish this in ScalaTest is to factor the individual fixtures into traits that can be composed using the stackable trait pattern. This can be done, for example, by placing `withFixture` methods in several traits, each of which call `super.withFixture`. Here's an example in which the `StringBuilder` and `ListBuffer[String]` fixtures used in the previous examples have been factored out into two stackable fixture traits named `Builder` and `Buffer`:

    import org.scalatest.FunSuite
    import org.scalatest.AbstractSuite
    import collection.mutable.ListBuffer

    trait Builder extends AbstractSuite { this: Suite =>

      val builder = new StringBuilder

      abstract override def withFixture(test: NoArgTest) {
        builder.append("ScalaTest is ")
        try {
          super.withFixture(test) // To be stackable, must call super.withFixture
        }
        finally {
          builder.clear()
        }
      }
    }

    trait Buffer extends AbstractSuite { this: Suite =>

      val buffer = new ListBuffer[String]

      abstract override def withFixture(test: NoArgTest) {
        try {
          super.withFixture(test) // To be stackable, must call super.withFixture
        }
        finally {
          buffer.clear()
        }
      }
    }

    class ExampleSuite extends FunSuite with Builder with Buffer {

      test("easy") {
        builder.append("easy!")
        assert(builder.toString === "ScalaTest is easy!")
        assert(buffer.isEmpty)
        buffer += "sweet"
      }

      test("fun") {
        builder.append("fun!")
        assert(builder.toString === "ScalaTest is fun!")
        assert(buffer.isEmpty)
        buffer += "clear"
      }
    }

By mixing in both the `Builder` and `Buffer` traits, `ExampleSuite` gets both fixtures, which will be initialized before each test and cleaned up after. The order the traits are mixed together determines the order of execution. In this case, `Builder` is "super" to Buffer. If you wanted `Buffer` to be "super" to `Builder`, you need only switch the order you mix them together, like this:

    class Example2Suite extends FunSuite with Buffer with Builder

And if you only need one fixture you mix in only that trait:

    class Example3Suite extends FunSuite with Builder

Another way to create stackable fixture traits is by extending the `BeforeAndAfterEach` and/or `BeforeAndAfterAll` traits. `BeforeAndAfterEach` has a `beforeEach` method that will be run before each test (like JUnit's `setUp`), and an `afterEach` method that will be run after (like JUnit's `tearDown`). Similarly, `BeforeAndAfterAll` has a `beforeAll` method that will be run before all tests, and an `afterAll` method that will be run after all tests. Here's what the previously shown example would look like if it were rewritten to use the `BeforeAndAfterEach` methods instead of `withFixture`:

    import org.scalatest.FunSuite
    import org.scalatest.BeforeAndAfterEach
    import collection.mutable.ListBuffer

    trait Builder extends BeforeAndAfterEach { this: Suite =>

      val builder = new StringBuilder

      override def beforeEach() {
        builder.append("ScalaTest is ")
        super.beforeEach() // To be stackable, must call super.beforeEach
      }

      override def afterEach() {
        try {
          super.afterEach() // To be stackable, must call super.afterEach
        }
        finally {
          builder.clear()
        }
      }
    }

    trait Buffer extends BeforeAndAfterEach { this: Suite =>

      val buffer = new ListBuffer[String]

      override def afterEach() {
        try {
          super.afterEach() // To be stackable, must call super.afterEach
        }
        finally {
          buffer.clear()
        }
      }
    }

    class ExampleSuite extends FunSuite with Builder with Buffer {

      test("easy") {
        builder.append("easy!")
        assert(builder.toString === "ScalaTest is easy!")
        assert(buffer.isEmpty)
        buffer += "sweet"
      }

      test("fun") {
        builder.append("fun!")
        assert(builder.toString === "ScalaTest is fun!")
        assert(buffer.isEmpty)
        buffer += "clear"
      }
    }

To get the same ordering as `withFixture`, place your `super.beforeEach` call at the end of each `beforeEach` method, and the `super.afterEach` call at the beginning of each `afterEach` method, as shown in the previous example. It is a good idea to invoke `super.afterEach` in a `try` block and perform cleanup in a `finally` clause, as shown in the previous example, because this ensures the cleanup code is performed even if `super.afterAll` throws an exception.

One difference to bear in mind between the before-and-after traits and the `withFixture` methods, is that if a `withFixture` method completes abruptly with an exception, it is considered a failed test. By contrast, if any of the methods on the before-and-after traits (i.e., `before` and `after` of `BeforeAndAfter`, `beforeEach` and `afterEach` of `BeforeAndAfterEach`, and `beforeAll` and `afterAll` of `BeforeAndAfterAll`) complete abruptly, it is considered a failed suite, which will result in a `SuiteAborted` event.

#### Shared tests

Sometimes you may want to run the same test code on different fixture objects. In other words, you may want to write tests that are "shared" by different fixture objects. To accomplish this in a `FunSuite`, you first place shared tests in behavior functions. These behavior functions will be invoked during the construction phase of any `FunSuite` that uses them, so that the tests they contain will be registered as tests in that `FunSuite`. For example, given this stack class:

    import scala.collection.mutable.ListBuffer

    class Stack[T] {

      val MAX = 10
      private var buf = new ListBuffer[T]

      def push(o: T) {
        if (!full)
          o +: buf
        else
          throw new IllegalStateException("can't push onto a full stack")
      }

      def pop(): T = {
        if (!empty)
          buf.remove(0)
        else
          throw new IllegalStateException("can't pop an empty stack")
      }

      def peek: T = {
        if (!empty)
          buf(0)
        else
          throw new IllegalStateException("can't pop an empty stack")
      }

      def full: Boolean = buf.size == MAX
      def empty: Boolean = buf.size == 0
      def size = buf.size

      override def toString = buf.mkString("Stack(", ", ", ")")
    }

You may want to test the `Stack` class in different states: empty, full, with one item, with one item less than capacity, etc. You may find you have several tests that make sense any time the stack is non-empty. Thus you'd ideally want to run those same tests for three stack fixture objects: a full stack, a stack with a one item, and a stack with one item less than capacity. With shared tests, you can factor these tests out into a behavior function, into which you pass the stack fixture to use when running the tests. So in your `FunSuite` for stack, you'd invoke the behavior function three times, passing in each of the three stack fixtures so that the shared tests are run for all three fixtures.

You can define a behavior function that encapsulates these shared tests inside the `FunSuite` that uses them. If they are shared between different `FunSuite`s, however, you could also define them in a separate trait that is mixed into each `FunSuite` that uses them. For example, here the `nonEmptyStack` behavior function (in this case, a behavior method) is defined in a trait along with another method containing shared tests for non-full stacks:

    import org.scalatest.FunSuite

    trait FunSuiteStackBehaviors { this: FunSuite =>

      def nonEmptyStack(createNonEmptyStack: => Stack[Int], lastItemAdded: Int) {

        test("empty is invoked on this non-empty stack: " + createNonEmptyStack.toString) {
          val stack = createNonEmptyStack
          assert(!stack.empty)
        }

        test("peek is invoked on this non-empty stack: " + createNonEmptyStack.toString) {
          val stack = createNonEmptyStack
          val size = stack.size
          assert(stack.peek === lastItemAdded)
          assert(stack.size === size)
        }

        test("pop is invoked on this non-empty stack: " + createNonEmptyStack.toString) {
          val stack = createNonEmptyStack
          val size = stack.size
          assert(stack.pop === lastItemAdded)
          assert(stack.size === size - 1)
        }
      }

      def nonFullStack(createNonFullStack: => Stack[Int]) {

        test("full is invoked on this non-full stack: " + createNonFullStack.toString) {
          val stack = createNonFullStack
          assert(!stack.full)
        }

        test("push is invoked on this non-full stack: " + createNonFullStack.toString) {
          val stack = createNonFullStack
          val size = stack.size
          stack.push(7)
          assert(stack.size === size + 1)
          assert(stack.peek === 7)
        }
      }
    }

Given these behavior functions, you could invoke them directly, but `FunSuite` offers a DSL for the purpose, which looks like this:

    testsFor(nonEmptyStack(stackWithOneItem, lastValuePushed))
    testsFor(nonFullStack(stackWithOneItem))

If you prefer to use an imperative style to change fixtures, for example by mixing in `BeforeAndAfterEach` and reassigning a `stack` `var` in `beforeEach`, you could write your behavior functions in the context of that `var`, which means you wouldn't need to pass in the stack fixture because it would be in scope already inside the behavior function. In that case, your code would look like this:

    testsFor(nonEmptyStack) // assuming lastValuePushed is also in scope inside nonEmptyStack
    testsFor(nonFullStack)

The recommended style, however, is the functional, pass-all-the-needed-values-in style. Here's an example:

    import org.scalatest.FunSuite

    class StackFunSuite extends FunSuite with FunSuiteStackBehaviors {

      // Stack fixture creation methods
      def emptyStack = new Stack[Int]

      def fullStack = {
        val stack = new Stack[Int]
        for (i <- 0 until stack.MAX)
          stack.push(i)
        stack
      }

      def stackWithOneItem = {
        val stack = new Stack[Int]
        stack.push(9)
        stack
      }

      def stackWithOneItemLessThanCapacity = {
        val stack = new Stack[Int]
        for (i <- 1 to 9)
          stack.push(i)
        stack
      }

      val lastValuePushed = 9

      test("empty is invoked on an empty stack") {
        val stack = emptyStack
        assert(stack.empty)
      }

      test("peek is invoked on an empty stack") {
        val stack = emptyStack
        intercept[IllegalStateException] {
          stack.peek
        }
      }

      test("pop is invoked on an empty stack") {
        val stack = emptyStack
        intercept[IllegalStateException] {
          emptyStack.pop
        }
      }

      testsFor(nonEmptyStack(stackWithOneItem, lastValuePushed))
      testsFor(nonFullStack(stackWithOneItem))

      testsFor(nonEmptyStack(stackWithOneItemLessThanCapacity, lastValuePushed))
      testsFor(nonFullStack(stackWithOneItemLessThanCapacity))

      test("full is invoked on a full stack") {
        val stack = fullStack
        assert(stack.full)
      }

      testsFor(nonEmptyStack(fullStack, lastValuePushed))

      test("push is invoked on a full stack") {
        val stack = fullStack
        intercept[IllegalStateException] {
          stack.push(10)
        }
      }
    }

If you load these classes into the Scala interpreter (with scalatest's JAR file on the class path), and execute it, you'll see:

    scala> (new StackFunSuite).execute()
    StackFunSuite:
    - empty is invoked on an empty stack
    - peek is invoked on an empty stack
    - pop is invoked on an empty stack
    - empty is invoked on this non-empty stack: Stack(9)
    - peek is invoked on this non-empty stack: Stack(9)
    - pop is invoked on this non-empty stack: Stack(9)
    - full is invoked on this non-full stack: Stack(9)
    - push is invoked on this non-full stack: Stack(9)
    - empty is invoked on this non-empty stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1)
    - peek is invoked on this non-empty stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1)
    - pop is invoked on this non-empty stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1)
    - full is invoked on this non-full stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1)
    - push is invoked on this non-full stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1)
    - full is invoked on a full stack
    - empty is invoked on this non-empty stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
    - peek is invoked on this non-empty stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
    - pop is invoked on this non-empty stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
    - push is invoked on a full stack

One thing to keep in mind when using shared tests is that in ScalaTest, each test in a suite must have a unique name. If you register the same tests repeatedly in the same suite, one problem you may encounter is an exception at runtime complaining that multiple tests are being registered with the same test name. In a `FunSuite` there is no nesting construct analogous to `Spec`'s `describe` clause. Therefore, you need to do a bit of extra work to ensure that the test names are unique. If a duplicate test name problem shows up in a `FunSuite`, you'll need to pass in a prefix or suffix string to add to each test name. You can pass this string the same way you pass any other data needed by the shared tests, or just call `toString` on the shared fixture object. This is the approach taken by the previous `FunSuiteStackBehaviors` example.

Given this `FunSuiteStackBehaviors` trait, calling it with the `stackWithOneItem` fixture, like this:

    testsFor(nonEmptyStack(stackWithOneItem, lastValuePushed))

yields test names:

- `empty is invoked on this non-empty stack: Stack(9)`
- `peek is invoked on this non-empty stack: Stack(9)`
- `pop is invoked on this non-empty stack: Stack(9)`

Whereas calling it with the `stackWithOneItemLessThanCapacity` fixture, like this:

    testsFor(nonEmptyStack(stackWithOneItemLessThanCapacity, lastValuePushed))

yields different test names:

- `empty is invoked on this non-empty stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1)`
- `peek is invoked on this non-empty stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1)`
- `pop is invoked on this non-empty stack: Stack(9, 8, 7, 6, 5, 4, 3, 2, 1)`

Self Type
  FunSuite

Linear Supertypes
Suite, AbstractSuite, Assertions, AnyRef, Any
Ordering

1. Alphabetic
2. By inheritance

Inherited

1. Hide All
2. Show all

1. FunSuite
2. Suite
3. AbstractSuite
4. Assertions
5. AnyRef
6. Any

Visibility

1. Public
2. All

### Type Members

1. #### class Equalizer extends AnyRef

   Class used via an implicit conversion to enable any two objects to be compared with `===` in assertions in tests.

2. #### trait NoArgTest extends () ⇒ Unit

   A test function taking no arguments, which also provides a test name and config map.

### 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 asInstanceOf [T0] : T0

   Attributes
     final
   Definition Classes
     Any

7. #### def assert (o: Option[String]): Unit

   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`.

   o

     the `Option[String]` to assert

   Definition Classes
     Assertions

8. #### def assert (o: Option[String], clue: Any): Unit

   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`.

   o

     the `Option[String]` to assert

   clue

     An objects whose `toString` method returns a message to include in a failure report.

   Definition Classes
     Assertions

9. #### def assert (condition: Boolean, clue: Any): Unit

   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.

   condition

     the boolean condition to assert

   clue

     An objects whose `toString` method returns a message to include in a failure report.

   Definition Classes
     Assertions

10. #### def assert (condition: Boolean): Unit

    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`.

    condition

      the boolean condition to assert

    Definition Classes
      Assertions

11. #### def clone (): AnyRef

    Attributes
      protected[lang]
    Definition Classes
      AnyRef
    Annotations
      @throws()

12. #### implicit def convertToEqualizer (left: Any): Equalizer

    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 `Suite`s. 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)

    left

      the object whose type to convert to `Equalizer`.

    Attributes
      implicit
    Definition Classes
      Assertions

13. #### def eq (arg0: AnyRef): Boolean

    Attributes
      final
    Definition Classes
      AnyRef

14. #### def equals (arg0: Any): Boolean

    Definition Classes
      AnyRef → Any

15. #### def execute (testName: String = null, configMap: Map[String, Any] = Map(), color: Boolean = true, durations: Boolean = false, shortstacks: Boolean = false, fullstacks: Boolean = false, stats: Boolean = false): Unit

    Executes one or more tests in this `Suite`, printing results to the standard output.

    Executes one or more tests in this `Suite`, printing results to the standard output.

    This method invokes `run` on itself, passing in values that can be configured via the parameters to this method, all of which have default values. This behavior is convenient when working with ScalaTest in the Scala interpreter. Here's a summary of this method's parameters and how you can use them:

    The `testName` parameter

    If you leave `testName` at its default value (of `null`), this method will pass `None` to the `testName` parameter of `run`, and as a result all the tests in this suite will be executed. If you specify a `testName`, this method will pass `Some(testName)` to `run`, and only that test will be run. Thus to run all tests in a suite from the Scala interpreter, you can write:

        scala> (new ExampleSuite).execute()

    To run just the test named `"my favorite test"` in a suite from the Scala interpreter, you would write:

        scala> (new ExampleSuite).execute("my favorite test")

    Or:

        scala> (new ExampleSuite).execute(testName = "my favorite test")

    The `configMap` parameter

    If you provide a value for the `configMap` parameter, this method will pass it to `run`. If not, the default value of an empty `Map` will be passed. For more information on how to use a config map to configure your test suites, see the config map section in the main documentation for this trait. Here's an example in which you configure a run with the name of an input file:

        scala> (new ExampleSuite).execute(configMap = Map("inputFileName" -> "in.txt")

    The `color` parameter

    If you leave the `color` parameter unspecified, this method will configure the reporter it passes to `run` to print to the standard output in color (via ansi escape characters). If you don't want color output, specify false for `color`, like this:

        scala> (new ExampleSuite).execute(color = false)

    The `durations` parameter

    If you leave the `durations` parameter unspecified, this method will configure the reporter it passes to `run` to not print durations for tests and suites to the standard output. If you want durations printed, specify true for `durations`, like this:

        scala> (new ExampleSuite).execute(durations = true)

    The `shortstacks` and `fullstacks` parameters

    If you leave both the `shortstacks` and `fullstacks` parameters unspecified, this method will configure the reporter it passes to `run` to not print stack traces for failed tests if it has a stack depth that identifies the offending line of test code. If you prefer a short stack trace (10 to 15 stack frames) to be printed with any test failure, specify true for `shortstacks`:

        scala> (new ExampleSuite).execute(shortstacks = true)

    For full stack traces, set `fullstacks` to true:

        scala> (new ExampleSuite).execute(fullstacks = true)

    If you specify true for both `shortstacks` and `fullstacks`, you'll get full stack traces.

    The `stats` parameter

    If you leave the `stats` parameter unspecified, this method will not fire `RunStarting` and either `RunCompleted` or `RunAborted` events to the reporter it passes to `run`. If you specify true for `stats`, this method will fire the run events to the reporter, and the reporter will print the expected test count before the run, and various statistics after, including the number of suites completed and number of tests that succeeded, failed, were ignored or marked pending. Here's how you get the stats:

        scala> (new ExampleSuite).execute(stats = true)

    To summarize, this method will pass to `run`:

    - `testName` - `None` if this method's `testName` parameter is left at its default value of `null`, else `Some(testName)`.
    - `reporter` - a reporter that prints to the standard output
    - `stopper` - a `Stopper` whose `apply` method always returns `false`
    - `filter` - a `Filter` constructed with `None` for `tagsToInclude` and `Set()` for `tagsToExclude`
    - `configMap` - the `configMap` passed to this method
    - `distributor` - `None`
    - `tracker` - a new `Tracker`

    Note: In ScalaTest, the terms "execute" and "run" basically mean the same thing and can be used interchangably. The reason this method isn't named `run` is that it takes advantage of default arguments, and you can't mix overloaded methods and default arguments in Scala. (If named `run`, this method would have the same name but different arguments than the main `run` method that takes seven arguments. Thus it would overload and couldn't be used with default argument values.)

    Design note: This method has two "features" that may seem unidiomatic. First, the default value of `testName` is `null`. Normally in Scala the type of `testName` would be `Option[String]` and the default value would be `None`, as it is in this trait's `run` method. The `null` value is used here for two reasons. First, in ScalaTest 1.5, `execute` was changed from four overloaded methods to one method with default values, taking advantage of the default and named parameters feature introduced in Scala 2.8. To not break existing source code, `testName` needed to have type `String`, as it did in two of the overloaded `execute` methods prior to 1.5. The other reason is that `execute` has always been designed to be called primarily from an interpeter environment, such as the Scala REPL (Read-Evaluate-Print-Loop). In an interpreter environment, minimizing keystrokes is king. A `String` type with a `null` default value lets users type `suite.execute("my test name")` rather than `suite.execute(Some("my test name"))`, saving several keystrokes.

    The second non-idiomatic feature is that `shortstacks` and `fullstacks` are all lower case rather than camel case. This is done to be consistent with the `Shell`, which also uses those forms. The reason lower case is used in the `Shell` is to save keystrokes in an interpreter environment. Most Unix commands, for example, are all lower case, making them easier and quicker to type. In the ScalaTest `Shell`, methods like `shortstacks`, `fullstacks`, and `nostats`, etc., are designed to be all lower case so they feel more like shell commands than methods.

    testName

      the name of one test to run.

    configMap

      a `Map` of key-value pairs that can be used by the executing `Suite` of tests.

    color

      a boolean that configures whether output is printed in color

    durations

      a boolean that configures whether test and suite durations are printed to the standard output

    shortstacks

      a boolean that configures whether short stack traces should be printed for test failures

    fullstacks

      a boolean that configures whether full stack traces should be printed for test failures

    stats

      a boolean that configures whether test and suite statistics are printed to the standard output

    Attributes
      final
    Definition Classes
      Suite

16. #### def expect (expected: Any)(actual: Any): Unit

    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.

    expected

      the expected value

    actual

      the actual value, which should equal the passed `expected` value

    Definition Classes
      Assertions

17. #### def expect (expected: Any, clue: Any)(actual: Any): Unit

    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`.

    expected

      the expected value

    clue

      An object whose `toString` method returns a message to include in a failure report.

    actual

      the actual value, which should equal the passed `expected` value

    Definition Classes
      Assertions

18. #### 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.

    This trait's implementation of this method returns the sum of:

    - the size of the `testNames` `List`, minus the number of tests marked as ignored
    - the sum of the values obtained by invoking `expectedTestCount` on every nested `Suite` contained in `nestedSuites`
    filter

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

    Definition Classes
      Suite → AbstractSuite

19. #### def fail (cause: Throwable): Nothing

    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()`.

    cause

      a `Throwable` that indicates the cause of the failure.

    Definition Classes
      Assertions

20. #### def fail (message: String, cause: Throwable): Nothing

    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.

    message

      A message describing the failure.

    cause

      A `Throwable` that indicates the cause of the failure.

    Definition Classes
      Assertions

21. #### def fail (message: String): Nothing

    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.

    message

      A message describing the failure.

    Definition Classes
      Assertions

22. #### def fail (): Nothing

    Throws `TestFailedException` to indicate a test failed.

    Throws `TestFailedException` to indicate a test failed.

    Definition Classes
      Assertions

23. #### def finalize (): Unit

    Attributes
      protected[lang]
    Definition Classes
      AnyRef
    Annotations
      @throws()

24. #### def getClass (): java.lang.Class[_]

    Attributes
      final
    Definition Classes
      AnyRef

25. #### def hashCode (): Int

    Definition Classes
      AnyRef → Any

26. #### def ignore (testName: String, testTags: Tag*)(testFun: ⇒ Unit): Unit

    Register a test to ignore, which has the specified name, optional tags, and function value that takes no arguments.

    Register a test to ignore, which has the specified name, optional tags, and function value that takes no arguments. This method will register the test for later ignoring via an invocation of one of the `run` methods. This method exists to make it easy to ignore an existing test by changing the call to `test` to `ignore` without deleting or commenting out the actual test code. The test will not be run, but a report will be sent that indicates the test was ignored. The passed test name must not have been registered previously on this `FunSuite` instance.

    testName

      the name of the test

    testTags

      the optional list of tags for this test

    testFun

      the test function

    Attributes
      protected

27. #### implicit def info : Informer

    Returns an `Informer` that during test execution will forward strings (and other objects) passed to its `apply` method to the current reporter.

    Returns an `Informer` that during test execution will forward strings (and other objects) passed to its `apply` method to the current reporter. If invoked in a constructor, it will register the passed string for forwarding later during test execution. If invoked while this `FunSuite` is being executed, such as from inside a test function, it will forward the information to the current reporter immediately. If invoked at any other time, it will throw an exception. This method can be called safely by any thread.

    Attributes
      protected implicit

28. #### def intercept [T <: AnyRef] (f: ⇒ Any)(implicit manifest: Manifest[T]): T

    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`.

    f

      the function value that should throw the expected exception

    manifest

      an implicit `Manifest` representing the type of the specified type parameter.

    returns

      the intercepted exception, if it is of the expected type

    Definition Classes
      Assertions

29. #### def isInstanceOf [T0] : Boolean

    Attributes
      final
    Definition Classes
      Any

30. #### def ne (arg0: AnyRef): Boolean

    Attributes
      final
    Definition Classes
      AnyRef

31. #### def nestedSuites : List[Suite]

    A `List` of this `Suite` object's nested `Suite`s.

    A `List` of this `Suite` object's nested `Suite`s. If this `Suite` contains no nested `Suite`s, this method returns an empty `List`. This trait's implementation of this method returns an empty `List`.

    Definition Classes
      Suite → AbstractSuite

32. #### def notify (): Unit

    Attributes
      final
    Definition Classes
      AnyRef

33. #### def notifyAll (): Unit

    Attributes
      final
    Definition Classes
      AnyRef

34. #### def pending : PendingNothing

    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.

    Definition Classes
      Suite

35. #### def pendingUntilFixed (f: ⇒ Unit): Unit

    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.

    f

      a block of code, which if it completes abruptly, should trigger a `TestPendingException`

    Definition Classes
      Suite

36. #### def run (testName: Option[String], reporter: Reporter, stopper: Stopper, filter: Filter, configMap: Map[String, Any], distributor: Option[Distributor], tracker: Tracker): Unit

    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 `runTests`s. 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.)

    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`.

    reporter

      the `Reporter` to which results will be reported

    stopper

      the `Stopper` that will be consulted to determine whether to stop execution early.

    filter

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

    configMap

      a `Map` of key-value pairs that can be used by the executing `Suite` of tests.

    distributor

      an optional `Distributor`, into which to put nested `Suite`s to be run by another entity, such as concurrently by a pool of threads. If `None`, nested `Suite`s will be run sequentially.

    tracker

      a `Tracker` tracking `Ordinal`s being fired by the current thread.

    Definition Classes
      FunSuite → Suite → AbstractSuite

37. #### def runNestedSuites (reporter: Reporter, stopper: Stopper, filter: Filter, configMap: Map[String, Any], distributor: Option[Distributor], tracker: Tracker): Unit

    Run zero to many of this `Suite`'s nested `Suite`s.

    Run zero to many of this `Suite`'s nested `Suite`s.

    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 `Suite`s 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`.

    reporter

      the `Reporter` to which results will be reported

    stopper

      the `Stopper` that will be consulted to determine whether to stop execution early.

    filter

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

    configMap

      a `Map` of key-value pairs that can be used by the executing `Suite` of tests.

    distributor

      an optional `Distributor`, into which to put nested `Suite`s to be run by another entity, such as concurrently by a pool of threads. If `None`, nested `Suite`s will be run sequentially.

    tracker

      a `Tracker` tracking `Ordinal`s being fired by the current thread.

    Attributes
      protected
    Definition Classes
      Suite → AbstractSuite

38. #### def runTest (testName: String, reporter: Reporter, stopper: Stopper, configMap: Map[String, Any], tracker: Tracker): Unit

    Run a test.

    Run a test. This trait's implementation runs the test registered with the name specified by `testName`.

    testName

      the name of one test to run.

    reporter

      the `Reporter` to which results will be reported

    stopper

      the `Stopper` that will be consulted to determine whether to stop execution early.

    configMap

      a `Map` of properties that can be used by the executing `Suite` of tests.

    tracker

      a `Tracker` tracking `Ordinal`s being fired by the current thread.

    Attributes
      protected
    Definition Classes
      FunSuite → Suite → AbstractSuite

39. #### def runTests (testName: Option[String], reporter: Reporter, stopper: Stopper, filter: Filter, configMap: Map[String, Any], distributor: Option[Distributor], tracker: Tracker): Unit

    Run zero to many of this `Spec`'s tests.

    Run zero to many of this `Spec`'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`.

    reporter

      the `Reporter` to which results will be reported

    stopper

      the `Stopper` that will be consulted to determine whether to stop execution early.

    filter

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

    configMap

      a `Map` of key-value pairs that can be used by the executing `Suite` of tests.

    distributor

      an optional `Distributor`, into which to put nested `Suite`s to be run by another entity, such as concurrently by a pool of threads. If `None`, nested `Suite`s will be run sequentially.

    tracker

      a `Tracker` tracking `Ordinal`s being fired by the current thread.

    Attributes
      protected
    Definition Classes
      FunSuite → Suite → AbstractSuite

40. #### def suiteName : String

    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 `Report`s to pass to the `suiteStarting`, `suiteCompleted`, and `suiteAborted` methods of the `Reporter`.

    returns

      this `Suite` object's suite name.

    Definition Classes
      Suite

41. #### def synchronized [T0] (arg0: ⇒ T0): T0

    Attributes
      final
    Definition Classes
      AnyRef

42. #### def tags : Map[String, Set[String]]

    A `Map` whose keys are `String` tag names to which tests in this `FunSuite` belong, and values the `Set` of test names that belong to each tag.

    A `Map` whose keys are `String` tag names to which tests in this `FunSuite` belong, and values the `Set` of test names that belong to each tag. If this `FunSuite` contains no tags, this method returns an empty `Map`.

    This trait's implementation returns tags that were passed as strings contained in `Tag` objects passed to methods `test` and `ignore`.

    Definition Classes
      FunSuite → Suite → AbstractSuite

43. #### def test (testName: String, testTags: Tag*)(testFun: ⇒ Unit): Unit

    Register a test with the specified name, optional tags, and function value that takes no arguments.

    Register a test with the specified name, optional tags, and function value that takes no arguments. This method will register the test for later execution via an invocation of one of the `run` methods. The passed test name must not have been registered previously on this `FunSuite` instance.

    testName

      the name of the test

    testTags

      the optional list of tags for this test

    testFun

      the test function

    Attributes
      protected

44. #### def testNames : Set[String]

    An immutable `Set` of test names.

    An immutable `Set` of test names. If this `FunSuite` contains no tests, this method returns an empty `Set`.

    This trait's implementation of this method will return a set that contains the names of all registered tests. The set's iterator will return those names in the order in which the tests were registered.

    Definition Classes
      FunSuite → Suite → AbstractSuite

45. #### def testsFor (unit: Unit): Unit

    Registers shared tests.

    Registers shared tests.

    This method enables the following syntax for shared tests in a `FunSuite`:

        testsFor(nonEmptyStack(lastValuePushed))

    This method just provides syntax sugar intended to make the intent of the code clearer. Because the parameter passed to it is type `Unit`, the expression will be evaluated before being passed, which is sufficient to register the shared tests. For examples of shared tests, see the Shared tests section in the main documentation for this trait.

    Attributes
      protected

46. #### def toString (): String

    Definition Classes
      AnyRef → Any

47. #### def wait (): Unit

    Attributes
      final
    Definition Classes
      AnyRef
    Annotations
      @throws()

48. #### def wait (arg0: Long, arg1: Int): Unit

    Attributes
      final
    Definition Classes
      AnyRef
    Annotations
      @throws()

49. #### def wait (arg0: Long): Unit

    Attributes
      final
    Definition Classes
      AnyRef
    Annotations
      @throws()

50. #### def withClue (clue: Any)(fun: ⇒ Unit): Unit

    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

    Definition Classes
      Assertions

51. #### def withFixture (test: NoArgTest): Unit

    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 `var`s in this `Suite` or initializing a globally accessible external database. If you want to avoid reassigning instance `var`s 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.

    test

      the no-arg test function to run with a fixture

    Attributes
      protected
    Definition Classes
      Suite → AbstractSuite

### Inherited from Suite

### Inherited from AbstractSuite

### Inherited from Assertions

### Inherited from AnyRef

### Inherited from Any