org.scalatest

Suite

trait Suite extends Assertions with AbstractSuite

A suite of tests. A Suite instance 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 other Suite subtraits 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, and JUnit3Suite.

For JUnit 4 users

If you are using JUnit 4 and you want to write JUnit 4 tests in Scala, look at JUnitSuite, and JUnitRunner. With JUnitRunner, 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, and WordSpec. Otherwise, if you just want to write tests and don't want to combine testing with specifying, look at FunSuite or 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 Suite and define test methods. Test methods have names of the form testX, where X is some unique, hopefully meaningful, string. A test method must be public and can have any result type, but the most common result type is Unit. 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 Suite by invoking on it one of four overloaded execute methods. 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 run MySuite from within the Scala interpreter, you could write:

scala> (new MySuite).execute()

And you would see:

Test Starting - MySuite: testAddition
Test Succeeded - MySuite: testAddition
Test Starting - MySuite: testSubtraction
Test Succeeded - MySuite: testSubtraction

Or, to run just the testAddition method, you could write:

scala> (new MySuite).execute("testAddition")

And you would see:

Test Starting - MySuite: testAddition
Test Succeeded - MySuite: testAddition

Two other execute methods that are intended to be run from the interpreter accept a "config" map of key-value pairs (see Config map, below). Each of these execute methods invokes a run method takes seven parameters. This run method, which actually executes the suite, will usually be invoked by a test runner, such as org.scalatest.tools.Runner or an IDE. See the documentation for Runner for more detail.

Assertions and

Inside test methods in a Suite, you can write assertions by invoking assert and passing in a Boolean expression, such as:

val left = 2
val right = 1
assert(left == right)

If the passed expression is true, assert will return normally. If false, assert will complete abruptly with a TestFailedException. This exception is usually not caught by the test method, which means the test method itself will complete abruptly by throwing the TestFailedException. Any test method that completes abruptly with a TestFailedException or any Exception is considered a failed test. A test method that returns normally is considered a successful test.

If you pass a Boolean expression to assert, a failed assertion will be reported, but without reporting the left and right values. You can alternatively encode these values in a String passed as a second argument to assert, as in:

val left = 2
val right = 1
assert(left == right, left + " did not equal " + right)

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 trait Assertions which trait Suite extends.) You use it like this:

val left = 2
val right = 1
assert(left === right)

Because you use === here instead of ==, the failure report will include the left and right values. For example, the detail message in the thrown TestFailedException from the assert shown 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 ScalaTest Suite where you'd use assertEquals in a JUnit TestCase. The === operator is made possible by an implicit conversion from Any to Equalizer. If you're curious to understand the mechanics, see the documentation for Equalizer and the convertToEqualizer method.

Expected results

Although === provides a natural, readable extension to Scala's assert mechanism, 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 called left and right, because if one were named expected and the other actual, it would be difficult for people to remember which was which. To help with these limitations of assertions, Suite includes a method called expect that can be used as an alternative to assert with ===. To use expect, you place the expected value in parentheses after expect, 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 is a - b. This expectation will fail, and the detail message in the TestFailedException will 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 charAt throws IndexOutOfBoundsException as expected, control will transfer to the catch case, which does nothing. If, however, charAt fails to throw an exception, the next statement, fail(), will be executed. The fail method always completes abruptly with a TestFailedException, thereby signaling a failed test.

To make this common use case easier to express and read, ScalaTest provides an intercept method. You use it like this:

val s = "hi"
intercept[IndexOutOfBoundsException] {
  s.charAt(-1)
}

This code behaves much like the previous example. If charAt throws an instance of IndexOutOfBoundsException, intercept will return that exception. But if charAt completes normally, or throws a different exception, intercept will complete abruptly with a TestFailedException. The intercept method 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 trait MustMatchers.

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 assertEquals methods 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 Suite can refer to a collection of other Suites, which are called nested Suites. Those nested Suites can in turn have their own nested Suites, and so on. Large test suites can be organized, therefore, as a tree of nested Suites. This trait's run method, in addition to invoking its test methods, invokes run on each of its nested Suites.

A List of a Suite's nested Suites can be obtained by invoking its nestedSuites method. If you wish to create a Suite that serves as a container for nested Suites, whether or not it has test methods of its own, simply override nestedSuites to return a List of the nested Suites. Because this is a common use case, ScalaTest provides a convenience SuperSuite class, which takes a List of nested Suites 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:

scala> (new AlphabetSuite).run()

You will see reports printed to the standard output that indicate nested suites—ASuite, BSuite, and CSuite—were run.

Note that Runner can discover Suites automatically, so you need not necessarily specify SuperSuites explicitly. See the documentation for Runner for 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 sum and diff in the previous MySuite examples. 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 to shared is 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 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 vars between tests. Before going that route, you may wish to consider some approaches that avoid vars. 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 Suite require 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 simply vals 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.

Although the create-fixture 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, one option is to mix in the BeforeAndAfterEach trait. BeforeAndAfterEach's beforeEach method will be run before, and its afterEach method after, each test (like JUnit's setUp and tearDown methods, 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 reader is a var, so it can be reinitialized between tests by the beforeEach method.

Although the BeforeAndAfterEach approach 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: overriding withFixture(NoArgTest). To execute each test, Suite's implementation of the runTest method wraps an invocation of the appropriate test method in a no-arg function. runTest passes that test function to the withFixture(NoArgTest) method, which is responsible for actually running the test by invoking the function. Suite's implementation of withFixture(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 in BeforeAndAfterEach, 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 FixtureSuite trait from the org.scalatest.fixture package. Tests in an org.scalatest.fixture.FixtureSuite can have a fixture object passed in as a parameter. You must indicate the type of the fixture object by defining the Fixture type member and define a withFixture method that takes a one-arg test function. (A FixtureSuite has two overloaded withFixture methods, therefore, one that takes a OneArgTest and the other, inherited from Suite, that takes a NoArgTest.) Inside the withFixture(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, a FixtureSuite will pass a function that invokes the code of a test to withFixture(OneArgTest). Your withFixture(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 the withFixture(OneArgTest) method of a FixtureSuite, 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 BeforeAndAfterEach approach shown previously and the immutable FixtureSuite approach shown here is that two of the FixtureSuite's test methods take a FileReader as a parameter. Otherwise the test code is identical. One benefit of the explicit parameter is that, as demonstrated by the testWithoutAFixture method, a FixtureSuite test method need not take the fixture. (Tests that don't take a fixture as a parameter are passed to the withFixture that takes a NoArgTest, shown previously.) So you can have some tests that take a fixture, and others that don't. In this case, the FixtureSuite provides documentation indicating which test methods use the fixture and which don't, whereas the BeforeAndAfterEach approach 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 @BeforeClass and @AfterClass annotations in JUnit 4, you can use the beforeAll and afterAll methods of BeforeAndAfterAll. See the documentation for BeforeAndAfterAll for 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 run as a Map[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 to run, runNestedSuites, runTests, and runTest, 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 the org.scalatest.fixture package. (See the documentation for FixtureSuite for 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 a Suite, 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 in Suites, simply define a new Java annotation that itself is annotated with the org.scalatest.TagAnnotation annotation. (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 named SlowAsMolasses, 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 Suite test method into the SlowAsMolasses group (i.e., tag it as being SlowAsMolasses) like this:

@SlowAsMolasses
def testSleeping() = sleep(1000000)

The primary run method takes a Filter, whose constructor takes an optional Set[String]s 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.

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 Ignore annotation 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 MySuite with:

scala> (new MySuite).run()

It will run only testAddition and report that testSubtraction was ignored. You'll see:

Test Starting - MySuite: testAddition
Test Succeeded - MySuite: testAddition
Test Ignored - MySuite: testSubtraction

Ignore is implemented as a tag. The Filter class effectively adds org.scalatest.Ignore to the tagsToExclude Set if it not already in the tagsToExclude set passed to its primary constructor. The only difference between org.scalatest.Ignore and the tags you may define and exclude is that ScalaTest reports ignored tests to the Reporter. 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 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.

Although pending tests may be used more often in specification-style suites, such as org.scalatest.Spec, you can also use it in Suite, 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 MySuite with:

scala> (new MySuite).run()

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

Test Starting - MySuite: testAddition
Test Succeeded - MySuite: testAddition
Test Starting - MySuite: testSubtraction
Test Pending - MySuite: testSubtraction

Informers

One of the parameters to the primary run method is an 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 Suite's methods will be sufficient, but occasionally you may wish to provide custom information to the Reporter from a test method. For this purpose, you can optionally include an Informer parameter in a test method, and then pass the extra information to the Informer via its apply method. The Informer will then pass the information to the Reporter by sending an InfoProvided event. 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 Suite from the interpreter, you will see the message included in the printed report:

scala> (new MySuite).run()
Test Starting - MySuite: testAddition(Reporter)
Info Provided - MySuite: testAddition(Reporter)
  Addition seems to work
Test Succeeded - MySuite: testAddition(Reporter)

Executing suites in parallel

The primary run method takes as its last parameter an optional Distributor. If a Distributor is passed in, this trait's implementation of run puts its nested Suites into the distributor rather than executing them directly. The caller of run is responsible for ensuring that some entity runs the Suites placed into the distributor. The -c command line parameter to Runner, for example, will cause Suites put into the Distributor to be run in parallel via a pool of threads.

Treatment of java.lang.Errors

The Javadoc documentation for java.lang.Error states:

An Error is a subclass of Throwable that indicates serious problems that a reasonable application should not try to catch. Most such errors are abnormal conditions.

Because Errors are used to denote serious errors, trait Suite and its subtypes in the ScalaTest API do not always treat a test that completes abruptly with an Error as 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 an OutOfMemoryError, it will not be reported as a test failure, but will instead cause the run to abort. Because not everyone uses Errors only to represent serious problems, however, ScalaTest only behaves this way for the following exception types (and their subclasses):

The previous list includes all Errors that exist as part of Java 1.5 API, excluding java.lang.AssertionError. ScalaTest does treat a thrown AssertionError as an indication of a test failure. In addition, any other Error that is not an instance of a type mentioned in the previous list will be caught by the Suite traits in the ScalaTest API and reported as the cause of a test failure.

Although trait Suite and all its subtypes in the ScalaTest API consistently behave this way with regard to Errors, this behavior is not required by the contract of Suite. Subclasses and subtraits that you define, for example, may treat all Errors as test failures, or indicate errors in some other way that has nothing to do with exceptions.

Extensibility

Trait Suite provides 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:

For example, this trait's implementation of testNames performs reflection to discover methods starting with test, and places these in a Set whose iterator returns the names in alphabetical order. If you wish to run tests in a different order in a particular Suite, perhaps because a test named testAlpha can only succeed after a test named testBeta has run, you can override testNames so that it returns a Set whose iterator returns testBeta before testAlpha. (This trait's implementation of run will invoke tests in the order they come out of the testNames Set iterator.)

Alternatively, you may not like starting your test methods with test, and prefer using @Test annotations in the style of Java's JUnit 4 or TestNG. If so, you can override testNames to discover tests using either of these two APIs @Test annotations, or one of your own invention. (This is in fact how org.scalatest.junit.JUnitSuite and org.scalatest.testng.TestNGSuite work.)

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, FunSuite overrides testNames, runTest, and run such 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.junit and org.scalatest.testng exist to make this easy. No matter what legacy tests you may have, it is likely you can create or use an existing Suite subclass 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.

A suite of tests. A Suite instance 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 other Suite subtraits 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, and JUnit3Suite.

For JUnit 4 users

If you are using JUnit 4 and you want to write JUnit 4 tests in Scala, look at JUnitSuite, and JUnitRunner. With JUnitRunner, 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, and WordSpec. Otherwise, if you just want to write tests and don't want to combine testing with specifying, look at FunSuite or 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 Suite and define test methods. Test methods have names of the form testX, where X is some unique, hopefully meaningful, string. A test method must be public and can have any result type, but the most common result type is Unit. 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 Suite by invoking on it one of four overloaded execute methods. 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 run MySuite from within the Scala interpreter, you could write:

scala> (new MySuite).execute()

And you would see:

Test Starting - MySuite: testAddition
Test Succeeded - MySuite: testAddition
Test Starting - MySuite: testSubtraction
Test Succeeded - MySuite: testSubtraction

Or, to run just the testAddition method, you could write:

scala> (new MySuite).execute("testAddition")

And you would see:

Test Starting - MySuite: testAddition
Test Succeeded - MySuite: testAddition

Two other execute methods that are intended to be run from the interpreter accept a "config" map of key-value pairs (see Config map, below). Each of these execute methods invokes a run method takes seven parameters. This run method, which actually executes the suite, will usually be invoked by a test runner, such as org.scalatest.tools.Runner or an IDE. See the documentation for Runner for more detail.

Assertions and

Inside test methods in a Suite, you can write assertions by invoking assert and passing in a Boolean expression, such as:

val left = 2
val right = 1
assert(left == right)

If the passed expression is true, assert will return normally. If false, assert will complete abruptly with a TestFailedException. This exception is usually not caught by the test method, which means the test method itself will complete abruptly by throwing the TestFailedException. Any test method that completes abruptly with a TestFailedException or any Exception is considered a failed test. A test method that returns normally is considered a successful test.

If you pass a Boolean expression to assert, a failed assertion will be reported, but without reporting the left and right values. You can alternatively encode these values in a String passed as a second argument to assert, as in:

val left = 2
val right = 1
assert(left == right, left + " did not equal " + right)

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 trait Assertions which trait Suite extends.) You use it like this:

val left = 2
val right = 1
assert(left === right)

Because you use === here instead of ==, the failure report will include the left and right values. For example, the detail message in the thrown TestFailedException from the assert shown 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 ScalaTest Suite where you'd use assertEquals in a JUnit TestCase. The === operator is made possible by an implicit conversion from Any to Equalizer. If you're curious to understand the mechanics, see the documentation for Equalizer and the convertToEqualizer method.

Expected results

Although === provides a natural, readable extension to Scala's assert mechanism, 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 called left and right, because if one were named expected and the other actual, it would be difficult for people to remember which was which. To help with these limitations of assertions, Suite includes a method called expect that can be used as an alternative to assert with ===. To use expect, you place the expected value in parentheses after expect, 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 is a - b. This expectation will fail, and the detail message in the TestFailedException will 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 charAt throws IndexOutOfBoundsException as expected, control will transfer to the catch case, which does nothing. If, however, charAt fails to throw an exception, the next statement, fail(), will be executed. The fail method always completes abruptly with a TestFailedException, thereby signaling a failed test.

To make this common use case easier to express and read, ScalaTest provides an intercept method. You use it like this:

val s = "hi"
intercept[IndexOutOfBoundsException] {
  s.charAt(-1)
}

This code behaves much like the previous example. If charAt throws an instance of IndexOutOfBoundsException, intercept will return that exception. But if charAt completes normally, or throws a different exception, intercept will complete abruptly with a TestFailedException. The intercept method 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 trait MustMatchers.

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 assertEquals methods 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 Suite can refer to a collection of other Suites, which are called nested Suites. Those nested Suites can in turn have their own nested Suites, and so on. Large test suites can be organized, therefore, as a tree of nested Suites. This trait's run method, in addition to invoking its test methods, invokes run on each of its nested Suites.

A List of a Suite's nested Suites can be obtained by invoking its nestedSuites method. If you wish to create a Suite that serves as a container for nested Suites, whether or not it has test methods of its own, simply override nestedSuites to return a List of the nested Suites. Because this is a common use case, ScalaTest provides a convenience SuperSuite class, which takes a List of nested Suites 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:

scala> (new AlphabetSuite).run()

You will see reports printed to the standard output that indicate nested suites—ASuite, BSuite, and CSuite—were run.

Note that Runner can discover Suites automatically, so you need not necessarily specify SuperSuites explicitly. See the documentation for Runner for 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 sum and diff in the previous MySuite examples. 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 to shared is 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 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 vars between tests. Before going that route, you may wish to consider some approaches that avoid vars. 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 Suite require 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 simply vals 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.

Although the create-fixture 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, one option is to mix in the BeforeAndAfterEach trait. BeforeAndAfterEach's beforeEach method will be run before, and its afterEach method after, each test (like JUnit's setUp and tearDown methods, 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 reader is a var, so it can be reinitialized between tests by the beforeEach method.

Although the BeforeAndAfterEach approach 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: overriding withFixture(NoArgTest). To execute each test, Suite's implementation of the runTest method wraps an invocation of the appropriate test method in a no-arg function. runTest passes that test function to the withFixture(NoArgTest) method, which is responsible for actually running the test by invoking the function. Suite's implementation of withFixture(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 in BeforeAndAfterEach, 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 FixtureSuite trait from the org.scalatest.fixture package. Tests in an org.scalatest.fixture.FixtureSuite can have a fixture object passed in as a parameter. You must indicate the type of the fixture object by defining the Fixture type member and define a withFixture method that takes a one-arg test function. (A FixtureSuite has two overloaded withFixture methods, therefore, one that takes a OneArgTest and the other, inherited from Suite, that takes a NoArgTest.) Inside the withFixture(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, a FixtureSuite will pass a function that invokes the code of a test to withFixture(OneArgTest). Your withFixture(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 the withFixture(OneArgTest) method of a FixtureSuite, 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 BeforeAndAfterEach approach shown previously and the immutable FixtureSuite approach shown here is that two of the FixtureSuite's test methods take a FileReader as a parameter. Otherwise the test code is identical. One benefit of the explicit parameter is that, as demonstrated by the testWithoutAFixture method, a FixtureSuite test method need not take the fixture. (Tests that don't take a fixture as a parameter are passed to the withFixture that takes a NoArgTest, shown previously.) So you can have some tests that take a fixture, and others that don't. In this case, the FixtureSuite provides documentation indicating which test methods use the fixture and which don't, whereas the BeforeAndAfterEach approach 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 @BeforeClass and @AfterClass annotations in JUnit 4, you can use the beforeAll and afterAll methods of BeforeAndAfterAll. See the documentation for BeforeAndAfterAll for 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 run as a Map[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 to run, runNestedSuites, runTests, and runTest, 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 the org.scalatest.fixture package. (See the documentation for FixtureSuite for 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 a Suite, 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 in Suites, simply define a new Java annotation that itself is annotated with the org.scalatest.TagAnnotation annotation. (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 named SlowAsMolasses, 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 Suite test method into the SlowAsMolasses group (i.e., tag it as being SlowAsMolasses) like this:

@SlowAsMolasses
def testSleeping() = sleep(1000000)

The primary run method takes a Filter, whose constructor takes an optional Set[String]s 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.

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 Ignore annotation 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 MySuite with:

scala> (new MySuite).run()

It will run only testAddition and report that testSubtraction was ignored. You'll see:

Test Starting - MySuite: testAddition
Test Succeeded - MySuite: testAddition
Test Ignored - MySuite: testSubtraction

Ignore is implemented as a tag. The Filter class effectively adds org.scalatest.Ignore to the tagsToExclude Set if it not already in the tagsToExclude set passed to its primary constructor. The only difference between org.scalatest.Ignore and the tags you may define and exclude is that ScalaTest reports ignored tests to the Reporter. 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 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.

Although pending tests may be used more often in specification-style suites, such as org.scalatest.Spec, you can also use it in Suite, 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 MySuite with:

scala> (new MySuite).run()

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

Test Starting - MySuite: testAddition
Test Succeeded - MySuite: testAddition
Test Starting - MySuite: testSubtraction
Test Pending - MySuite: testSubtraction

Informers

One of the parameters to the primary run method is an 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 Suite's methods will be sufficient, but occasionally you may wish to provide custom information to the Reporter from a test method. For this purpose, you can optionally include an Informer parameter in a test method, and then pass the extra information to the Informer via its apply method. The Informer will then pass the information to the Reporter by sending an InfoProvided event. 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 Suite from the interpreter, you will see the message included in the printed report:

scala> (new MySuite).run()
Test Starting - MySuite: testAddition(Reporter)
Info Provided - MySuite: testAddition(Reporter)
  Addition seems to work
Test Succeeded - MySuite: testAddition(Reporter)

Executing suites in parallel

The primary run method takes as its last parameter an optional Distributor. If a Distributor is passed in, this trait's implementation of run puts its nested Suites into the distributor rather than executing them directly. The caller of run is responsible for ensuring that some entity runs the Suites placed into the distributor. The -c command line parameter to Runner, for example, will cause Suites put into the Distributor to be run in parallel via a pool of threads.

Treatment of java.lang.Errors

The Javadoc documentation for java.lang.Error states:

An Error is a subclass of Throwable that indicates serious problems that a reasonable application should not try to catch. Most such errors are abnormal conditions.

Because Errors are used to denote serious errors, trait Suite and its subtypes in the ScalaTest API do not always treat a test that completes abruptly with an Error as 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 an OutOfMemoryError, it will not be reported as a test failure, but will instead cause the run to abort. Because not everyone uses Errors only to represent serious problems, however, ScalaTest only behaves this way for the following exception types (and their subclasses):

The previous list includes all Errors that exist as part of Java 1.5 API, excluding java.lang.AssertionError. ScalaTest does treat a thrown AssertionError as an indication of a test failure. In addition, any other Error that is not an instance of a type mentioned in the previous list will be caught by the Suite traits in the ScalaTest API and reported as the cause of a test failure.

Although trait Suite and all its subtypes in the ScalaTest API consistently behave this way with regard to Errors, this behavior is not required by the contract of Suite. Subclasses and subtraits that you define, for example, may treat all Errors as test failures, or indicate errors in some other way that has nothing to do with exceptions.

Extensibility

Trait Suite provides 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:

For example, this trait's implementation of testNames performs reflection to discover methods starting with test, and places these in a Set whose iterator returns the names in alphabetical order. If you wish to run tests in a different order in a particular Suite, perhaps because a test named testAlpha can only succeed after a test named testBeta has run, you can override testNames so that it returns a Set whose iterator returns testBeta before testAlpha. (This trait's implementation of run will invoke tests in the order they come out of the testNames Set iterator.)

Alternatively, you may not like starting your test methods with test, and prefer using @Test annotations in the style of Java's JUnit 4 or TestNG. If so, you can override testNames to discover tests using either of these two APIs @Test annotations, or one of your own invention. (This is in fact how org.scalatest.junit.JUnitSuite and org.scalatest.testng.TestNGSuite work.)

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, FunSuite overrides testNames, runTest, and run such 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.junit and org.scalatest.testng exist to make this easy. No matter what legacy tests you may have, it is likely you can create or use an existing Suite subclass 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.

go to: companion
linear super types: AbstractSuite, Assertions, AnyRef, Any
known subclasses: TestNGSuite, TestNGWrapperSuite, JUnitWrapperSuite, JUnitSuite, JUnit3Suite, FixtureSuite, FixtureWordSpec, MultipleFixtureWordSpec, FixtureSpec, MultipleFixtureSpec, FixtureFunSuite, MultipleFixtureFunSuite, FixtureFlatSpec, MultipleFixtureFlatSpec, FixtureFeatureSpec, MultipleFixtureFeatureSpec, WordSpec, NestedSuites, SuperSuite, Spec, FunSuite, FlatSpec, FeatureSpec
self type: Suite
annotations: @serializable()
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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

    o != arg0 is the same as !(o == (arg0)).

    o != arg0 is the same as !(o == (arg0)).

    arg0

    the object to compare against this object for dis-equality.

    returns

    false if the receiver object is equivalent to the argument; true otherwise.

    attributes: final
    definition classes: Any

  3. def ## () : Int

    attributes: final
    definition classes: AnyRef → Any

  4. def $asInstanceOf [T0] () : T0

    attributes: final
    definition classes: AnyRef

  5. def $isInstanceOf [T0] () : Boolean

    attributes: final
    definition classes: AnyRef

  6. def == ( arg0 : AnyRef ) : Boolean

    o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).

    o == arg0 is the same as if (o eq null) arg0 eq null else o.equals(arg0).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    attributes: final
    definition classes: AnyRef

  7. def == ( arg0 : Any ) : Boolean

    o == arg0 is the same as o.equals(arg0).

    o == arg0 is the same as o.equals(arg0).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    attributes: final
    definition classes: Any

  8. def asInstanceOf [T0] : T0

    This method is used to cast the receiver object to be of type T0.

    This method is used to cast the receiver object to be of type T0.

    Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested typed.

    returns

    the receiver object.

    attributes: final
    definition classes: Any

  9. 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

  10. 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

  11. 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

  12. 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

  13. def clone () : AnyRef

    This method creates and returns a copy of the receiver object.

    This method creates and returns a copy of the receiver object.

    The default implementation of the clone method is platform dependent.

    returns

    a copy of the receiver object.

    attributes: protected[lang]
    definition classes: AnyRef
    annotations: @throws()

  14. 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 </code>Equalizer</code>.

    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)

    left

    the object whose type to convert to Equalizer.

    attributes: implicit
    definition classes: Assertions

  15. def eq ( arg0 : AnyRef ) : Boolean

    This method is used to test whether the argument (arg0) is a reference to the receiver object (this).

    This method is used to test whether the argument (arg0) is a reference to the receiver object (this).

    The eq method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on non-null instances of AnyRef: * It is reflexive: for any non-null instance x of type AnyRef, x.eq(x) returns true. * It is symmetric: for any non-null instances x and y of type AnyRef, x.eq(y) returns true if and only if y.eq(x) returns true. * It is transitive: for any non-null instances x, y, and z of type AnyRef if x.eq(y) returns true and y.eq(z) returns true, then x.eq(z) returns true.

    Additionally, the eq method has three other properties. * It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false. * For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false. * null.eq(null) returns true.

    When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

    arg0

    the object to compare against this object for reference equality.

    returns

    true if the argument is a reference to the receiver object; false otherwise.

    attributes: final
    definition classes: AnyRef

  16. def equals ( arg0 : Any ) : Boolean

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.

    This method is used to compare the receiver object (this) with the argument object (arg0) for equivalence.

    The default implementations of this method is an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation]: * It is reflexive: for any instance x of type Any, x.equals(x) should return true. * It is symmetric: for any instances x and y of type Any, x.equals(y) should return true if and only if y.equals(x) returns true. * It is transitive: for any instances x, y, and z of type AnyRef if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.

    If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is often necessary to override hashCode to ensure that objects that are "equal" (o1.equals(o2) returns true) hash to the same scala.Int (o1.hashCode.equals(o2.hashCode)).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    definition classes: AnyRef → Any

  17. def execute ( testName : String , configMap : Map[String, Any] ) : Unit

    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 output
    • stopper - a Stopper whose apply method always returns false
    • filter - a Filter constructed with None for tagsToInclude and Set() for tagsToExclude
    • configMap - the specified configMap Map[String, Any]
    • distributor - None
    • tracker - a new Tracker

    This 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().

    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.

    attributes: final

  18. def execute ( testName : String ) : Unit

    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 output
    • stopper - a Stopper whose apply method always returns false
    • filter - a Filter constructed with None for tagsToInclude and Set() for tagsToExclude
    • configMap - an empty Map[String, Any]
    • distributor - None
    • tracker - a new Tracker

    This 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().

    testName

    the name of one test to run.

    attributes: final

  19. def execute ( configMap : Map[String, Any] ) : Unit

    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 - None
    • 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 specified configMap Map[String, Any]
    • distributor - None
    • tracker - a new Tracker

    This 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().

    configMap

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

    attributes: final

  20. def execute () : Unit

    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 - None
    • 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 - an empty Map[String, Any]
    • distributor - None
    • tracker - a new Tracker

    This 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.

    attributes: final

  21. 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

  22. 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

  23. 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

  24. 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

  25. 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

  26. 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

  27. def fail () : Nothing

    Throws TestFailedException to indicate a test failed.

    Throws TestFailedException to indicate a test failed.

    definition classes: Assertions

  28. def finalize () : Unit

    This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.

    This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.

    The details of when and if the finalize method are invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

    attributes: protected[lang]
    definition classes: AnyRef
    annotations: @throws()

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

    Returns a representation that corresponds to the dynamic class of the receiver object.

    Returns a representation that corresponds to the dynamic class of the receiver object.

    The nature of the representation is platform dependent.

    returns

    a representation that corresponds to the dynamic class of the receiver object.

    attributes: final
    definition classes: AnyRef

  30. def groups : Map[String, Set[String]]

    The groups methods has been deprecated and will be removed in a future version of ScalaTest.

    The groups methods has been deprecated and will be removed in a future version of ScalaTest. Please call (and override) tags instead.

    attributes: final
    annotations: @deprecated()
      deprecated:

  31. def hashCode () : Int

    Returns a hash code value for the object.

    Returns a hash code value for the object.

    The default hashing algorithm is platform dependent.

    Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)) yet not be equal (o1.equals(o2) returns false). A degenerate implementation could always return 0. However, it is required that if two objects are equal (o1.equals(o2) returns true) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals method.

    returns

    the hash code value for the object.

    definition classes: AnyRef → Any

  32. 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

  33. def isInstanceOf [T0] : Boolean

    This method is used to test whether the dynamic type of the receiver object is T0.

    This method is used to test whether the dynamic type of the receiver object is T0.

    Note that the test result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested typed.

    returns

    true if the receiver object is an instance of erasure of type T0; false otherwise.

    attributes: final
    definition classes: Any

  34. def ne ( arg0 : AnyRef ) : Boolean

    o.ne(arg0) is the same as !(o.eq(arg0)).

    o.ne(arg0) is the same as !(o.eq(arg0)).

    arg0

    the object to compare against this object for reference dis-equality.

    returns

    false if the argument is not a reference to the receiver object; true otherwise.

    attributes: final
    definition classes: AnyRef

  35. def nestedSuites : List[Suite]

    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.

    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.

    definition classes: Suite → AbstractSuite

  36. def notify () : Unit

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    attributes: final
    definition classes: AnyRef

  37. def notifyAll () : Unit

    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    attributes: final
    definition classes: AnyRef

  38. 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.

  39. 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

  40. 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 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.)

    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 Suites to be run by another entity, such as concurrently by a pool of threads. If None, nested Suites will be run sequentially.

    tracker

    a Tracker tracking Ordinals being fired by the current thread.

    definition classes: Suite → AbstractSuite

  41. 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 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.

    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 Suites to be run by another entity, such as concurrently by a pool of threads. If None, nested Suites will be run sequentially.

    tracker

    a Tracker tracking Ordinals being fired by the current thread.

    attributes: protected
    definition classes: Suite → AbstractSuite

  42. 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 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.)

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

    tracker

    a Tracker tracking Ordinals being fired by the current thread.

    attributes: protected
    definition classes: Suite → AbstractSuite

  43. 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 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 method
    • reporter - the Reporter passed to this method, or one that wraps and delegates to it
    • stopper - the Stopper passed to this method, or one that wraps and delegates to it
    • configMap - the configMap Map passed to this method, or one that wraps and delegates to it

    This 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 it
    • stopper - the Stopper passed to this method, or one that wraps and delegates to it
    • configMap - the configMap passed to this method, or one that wraps and delegates to it

    If 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.

    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 Suites to be run by another entity, such as concurrently by a pool of threads. If None, nested Suites will be run sequentially.

    tracker

    a Tracker tracking Ordinals being fired by the current thread.

    attributes: protected
    definition classes: Suite → AbstractSuite

  44. 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 Reports to pass to the suiteStarting, suiteCompleted, and suiteAborted methods of the Reporter.

    returns

    this Suite object's suite name.

  45. def synchronized [T0] ( arg0 : ⇒ T0 ) : T0

    attributes: final
    definition classes: AnyRef

  46. 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. If this Suite contains no tags, this method returns an empty Map.

    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.

    definition classes: Suite → AbstractSuite

  47. def testNames : Set[String]

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

    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).

    definition classes: Suite → AbstractSuite

  48. def toString () : String

    Returns a string representation of the object.

    Returns a string representation of the object.

    The default representation is platform dependent.

    returns

    a string representation of the object.

    definition classes: AnyRef → Any

  49. def wait () : Unit

    attributes: final
    definition classes: AnyRef
    annotations: @throws()

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

    attributes: final
    definition classes: AnyRef
    annotations: @throws()

  51. def wait ( arg0 : Long ) : Unit

    attributes: final
    definition classes: AnyRef
    annotations: @throws()

  52. 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

  53. 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 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.

    test

    the no-arg test function to run with a fixture

    attributes: protected
    definition classes: Suite → AbstractSuite

Inherited from AbstractSuite

Inherited from Assertions

Inherited from AnyRef

Inherited from Any