org.scalatest

FunSuite

trait FunSuite extends Suite

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

import org.scalatest.FunSuite

class MySuite extends FunSuite {

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

test("subtraction") { val diff = 4 - 1 assert(diff === 3) assert(diff - 2 === 1) } }

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

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

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

Shared fixtures

A test fixture is objects or other artifacts (such as files, sockets, database connections, etc.) used by tests to do their work. You can use fixtures in FunSuites with the same approaches suggested for Suite in its documentation. The same text that appears in the test fixture section of Suite's documentation is repeated here, with examples changed from Suite to FunSuite.

If a fixture is used by only one test, then the definitions of the fixture objects can be local to the test function, such as the objects assigned to sum and diff in the previous MySuite examples. If multiple tests need to share a fixture, the best 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 functions:

import org.scalatest.FunSuite

class MySuite extends FunSuite {

// Sharing immutable fixture objects via instance variables val shared = 5

test("addition") { val sum = 2 + 3 assert(sum === shared) }

test("subtraction") { val diff = 7 - 2 assert(diff === shared) } }

In some cases, however, shared mutable fixture objects may be changed by tests 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 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 often involves reassigning vars between tests. Before going that route, you should 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 that needs the fixture, storing the fixture object or objects in local variables. Here's an example:

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

class MySuite extends FunSuite {

// create objects needed by tests and return as a tuple def createFixture = ( new StringBuilder("ScalaTest is "), new ListBuffer[String] )

test("easy") { val (builder, lbuf) = createFixture builder.append("easy!") assert(builder.toString === "ScalaTest is easy!") assert(lbuf.isEmpty) lbuf += "sweet" }

test("fun") { val (builder, lbuf) = createFixture builder.append("fun!") assert(builder.toString === "ScalaTest is fun!") assert(lbuf.isEmpty) } }

If different tests in the same FunSuite 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 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 FunSuite, 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.FunSuite
import org.scalatest.BeforeAndAfterEach
import java.io.FileReader
import java.io.FileWriter
import java.io.File

class MySuite extends FunSuite 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() }

test("reading from the temp file") { var builder = new StringBuilder var c = reader.read() while (c != -1) { builder.append(c.toChar) c = reader.read() } assert(builder.toString === "Hello, test!") }

test("first char of the temp file") { assert(reader.read() === 'H') }

test("without a fixture") { 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.FunSuite
import org.scalatest.BeforeAndAfterEach
import java.io.FileReader
import java.io.FileWriter
import java.io.File

class MySuite extends FunSuite {

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() } }

test("reading from the temp file") { var builder = new StringBuilder var c = reader.read() while (c != -1) { builder.append(c.toChar) c = reader.read() } assert(builder.toString === "Hello, test!") }

test("first char of the temp file") { assert(reader.read() === 'H') }

test("without a fixture") { assert(1 + 1 === 2) } }

If you prefer to keep your test classes immutable, one final variation is to use the FixtureFunSuite trait from the org.scalatest.fixture package. Tests in an org.scalatest.fixture.FixtureFunSuite 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 FixtureFunSuite 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 FixtureFunSuite 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 FixtureFunSuite, like this:

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

class MySuite extends FixtureFunSuite {

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 using the temp file test(reader) } finally { // Close and delete the temp file reader.close() val file = new File(FileName) file.delete() } }

test("reading from the temp file") { reader => var builder = new StringBuilder var c = reader.read() while (c != -1) { builder.append(c.toChar) c = reader.read() } assert(builder.toString === "Hello, test!") }

test("first char of the temp file") { reader => assert(reader.read() === 'H') }

test("without a fixture") { () => assert(1 + 1 === 2) } }

It is worth noting that the only difference in the test code between the mutable BeforeAndAfterEach approach shown here and the immutable FixtureFunSuite approach shown previously is that two of the FixtureFunSuite's test functions take a FileReader as a parameter via the "reader =>" at the beginning of the function. Otherwise the test code is identical. One benefit of the explicit parameter is that, as demonstrated by the "without a fixture" test, a FixtureFunSuite test need not take the fixture. So you can have some tests that take a fixture, and others that don't. In this case, the FixtureFunSuite provides documentation indicating which tests use the fixture and which don't, whereas the BeforeAndAfterEach approach does not. (If you have want to combine tests that take different fixture types in the same FunSuite, you can use MultipleFixtureFunSuite.)

If you want to execute code before and after all tests (and nested suites) in a suite, such 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.

Shared tests

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

import scala.collection.mutable.ListBuffer

class Stack[T] {

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

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

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

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

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

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

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

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

import org.scalatest.FunSuite

trait FunSuiteStackBehaviors { this: FunSuite =>

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

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

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

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

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

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

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

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

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

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

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

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

import org.scalatest.FunSuite

class StackFunSuite extends FunSuite with FunSuiteStackBehaviors {

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

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

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

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

val lastValuePushed = 9

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

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

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

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

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

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

testsFor(nonEmptyStack(fullStack, lastValuePushed))

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

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

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

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

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

testsFor(nonEmptyStack(stackWithOneItem, lastValuePushed))

yields test names:

Whereas calling it with the stackWithOneItemLessThanCapacity fixture, like this:

testsFor(nonEmptyStack(stackWithOneItemLessThanCapacity, lastValuePushed))

yields different test names:

Tagging tests

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

import org.scalatest.Tag

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

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

import org.scalatest.FunSuite

class MySuite extends FunSuite {

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

test("subtraction", SlowTest, DbTest) { val diff = 4 - 1 assert(diff === 3) assert(diff - 2 === 1) } }

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

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

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

import org.scalatest.FunSuite

class MySuite extends FunSuite {

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

test("subtraction") { val diff = 4 - 1 assert(diff === 3) assert(diff - 2 === 1) } }

If you run this version of MySuite with:

scala> (new MySuite).execute()

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

Test Ignored - MySuite: addition
Test Starting - MySuite: subtraction
Test Succeeded - MySuite: subtraction

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, has not yet been implemented.

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

import org.scalatest.FunSuite

class MySuite extends FunSuite {

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

def test("subtraction") (pending) }

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

scala> (new MySuite).execute()

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

Test Starting - MySuite: addition
Test Succeeded - MySuite: addition
Test Starting - MySuite: subtraction
Test Pending - MySuite: subtraction

Informers

One of the parameters to the primary run method is a Reporter, which will collect and report information about the running suite of tests. Information about suites and tests that were run, whether tests succeeded or failed, and tests that were ignored will be passed to the Reporter as the suite runs. Most often the reporting done by default by FunSuite's methods will be sufficient, but occasionally you may wish to provide custom information to the Reporter from a test. For this purpose, an Informer that will forward information to the current Reporter is provided via the info parameterless method. You can pass the extra information to the Informer via one of its apply methods. The Informer will then pass the information to the Reporter via an InfoProvided event. Here's an example:

import org.scalatest.FunSuite

class MySuite extends FunSuite {

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

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

Test Starting - MySuite: addition
Info Provided - MySuite.addition: Addition seems to work
Test Succeeded - MySuite: addition

Inherits

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

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

Value Members

  1. 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
  2. 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
  3. 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
  4. 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
  5. def convertToEqualizer(left: Any): Equalizer

    Implicit conversion from Any to Equalizer, used to enable assertions with === comparisons

    Implicit conversion from Any to Equalizer, used to enable assertions with === comparisons.

    For more information on this mechanism, see the documentation for Equalizer.

    Because trait Suite mixes in Assertions, this implicit conversion will always be available by default in ScalaTest 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
  6. 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 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 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
  7. 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
  8. 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
  9. 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: SuiteAbstractSuite
  10. 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
  11. 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
  12. 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
  13. def fail(): Nothing

    Throws TestFailedException to indicate a test failed

    Throws TestFailedException to indicate a test failed.

    definition classes: Assertions
  14. 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.

    definition classes: AnyRef ⇐ Any
  15. def intercept[T <: AnyRef](f: ⇒ Any)(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
  16. def nestedSuites: List[Suite]

    A List of this Suite object's nested Suites

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

    definition classes: SuiteAbstractSuite
  17. def pending: PendingNothing

    Throws TestPendingException to indicate a test is pending

    Throws TestPendingException to indicate a test is pending.

    A pending test is one that has been given a name but is not yet implemented. The purpose of pending tests is to facilitate a style of testing in which documentation of behavior is sketched out before tests are written to verify that behavior (and often, the before the behavior of the system being tested is itself implemented). Such sketches form a kind of specification of what tests and functionality to implement later.

    To support this style of testing, a test can be given a name that specifies one bit of behavior required by the system being tested. The test can also include some code that sends more information about the behavior to the reporter when the tests run. At the end of the test, it can call method pending, which will cause it to complete abruptly with TestPendingException. Because tests in ScalaTest can be designated as pending with TestPendingException, both the test name and any information sent to the reporter when running the test can appear in the report of a test run. (In other words, the code of a pending test is executed just like any other test.) However, because the test completes abruptly with TestPendingException, the test will be reported as pending, to indicate the actual test, and possibly the functionality it is intended to test, has not yet been implemented.

    Note: This method always completes abruptly with a TestPendingException. Thus it always has a side effect. Methods with side effects are usually invoked with parentheses, as in pending(). This method is defined as a parameterless method, in flagrant contradiction to recommended Scala style, because it forms a kind of DSL for pending tests. It enables tests in suites such as FunSuite or Spec to be denoted by placing "(pending)" after the test name, as in:

    test("that style rules are not laws") (pending)
    

    Readers of the code see "pending" in parentheses, which looks like a little note attached to the test name to indicate it is pending. Whereas "(pending()) looks more like a method call, "(pending)" lets readers stay at a higher level, forgetting how it is implemented and just focusing on the intent of the programmer who wrote the code.

    definition classes: Suite
  18. def pendingUntilFixed(f: ⇒ Unit): Unit

    Execute the passed block of code, and if it completes abruptly, throw TestPendingException, else throw TestFailedException

    Execute the passed block of code, and if it completes abruptly, throw TestPendingException, else throw TestFailedException.

    This method can be used to temporarily change a failing test into a pending test in such a way that it will automatically turn back into a failing test once the problem originally causing the test to fail has been fixed. At that point, you need only remove the pendingUntilFixed call. In other words, a pendingUntilFixed surrounding a block of code that isn't broken is treated as a test failure. The motivation for this behavior is to encourage people to remove pendingUntilFixed calls when there are no longer needed.

    This method facilitates a style of testing in which tests are written before the code they test. Sometimes you may encounter a test failure that requires more functionality than you want to tackle without writing more tests. In this case you can mark the bit of test code causing the failure with pendingUntilFixed. You can then write more tests and functionality that eventually will get your production code to a point where the original test won't fail anymore. At this point the code block marked with pendingUntilFixed will no longer throw an exception (because the problem has been fixed). This will in turn cause pendingUntilFixed to throw TestFailedException with a detail message explaining you need to go back and remove the pendingUntilFixed call as the problem orginally causing your test code to fail has been fixed.

    f

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

    definition classes: Suite
  19. 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:

    1. runNestedSuites(report, stopper, tagsToInclude, tagsToExclude, configMap, distributor)
    2. 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.

  20. 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.

    definition classes: Suite
  21. def tags: Map[String, Set[String]]

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

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

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

  22. def testNames: Set[String]

    An immutable Set of test names

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

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

  23. def toString(): String

    Returns a string representation of the object

    Returns a string representation of the object.

    The default representation is platform dependent.

    definition classes: AnyRef ⇐ Any