AsyncTestSuite

The base trait of ScalaTest's asynchronous testing styles, which defines a withFixture lifecycle method that accepts as its parameter a test function that returns a FutureOutcome.

The withFixture method add by this trait has the following signature and implementation:

def withFixture(test: NoArgAsyncTest): FutureOutcome = {
 test()
}

This trait enables testing of asynchronous code without blocking. Instead of returning Outcome like TestSuite's withFixture, this trait's withFixture method returns a FutureOutcome. Similarly, the apply method of test function interface, NoArgAsyncTest, returns FutureOutcome:

// In trait NoArgAsyncTest:
def apply(): FutureOutcome

The withFixture method supports async testing, because when the test function returns, the test body has not necessarily finished execution.

The recommended way to ensure cleanup is performed after a test body finishes execution is to use a complete-lastly clause, syntax that is defined in trait CompleteLastly, which this trait extends. Using cleanup-lastly will ensure that cleanup will occur whether FutureOutcome-producing code completes abruptly by throwing an exception, or returns normally yielding a FutureOutcome. In the latter case, complete-lastly will register the cleanup code to execute asynchronously when the FutureOutcome completes.

The withFixture method is designed to be stacked, and to enable this, you should always call the super implementation of withFixture, and let it invoke the test function rather than invoking the test function directly. In other words, instead of writing “test()”, you should write “super.withFixture(test)”. Thus, the recommended structure of a withFixture implementation that performs cleanup looks like this:

// Your implementation
override def withFixture(test: NoArgAsyncTest) = {
 // Perform setup here
 complete {
   super.withFixture(test) // Invoke the test function
 } lastly {
   // Perform cleanup here
 }
}

If you have no cleanup to perform, you can write withFixture like this instead:

// Your implementation
override def withFixture(test: NoArgAsyncTest) = {
 // Perform setup here
 super.withFixture(test) // Invoke the test function
}

The test function and withFixture method returns a FutureOutcome, a ScalaTest class that wraps a Scala Future[Outcome] and offers methods more specific to asynchronous test outcomes. In a Scala Future, any exception results in a scala.util.Failure. In a FutureOutcome, a thrown TestPendingException always results in a Pending, a thrown TestCanceledException always results in a Canceled, and any other exception, so long as it isn't suite-aborting, results in a Failed. This is true of the asynchronous test code itself that's represented by the FutureOutcome and any transformation or callback registered on the FutureOutcome in withFixture.

If you want to perform an action only for certain outcomes, you'll need to register code performing that action on the FutureOutcome using one of FutureOutcome's callback registration methods:

  • onSucceededThen - executed if the Outcome is a Succeeded.

  • onFailedThen - executed if the Outcome is a Failed.

  • onCanceledThen - executed if the Outcome is a Canceled.

  • onPendingThen - executed if the Outcome is a Pending.

  • onOutcomeThen - executed on any Outcome (i.e., no suite-aborting exception is thrown).

  • onAbortedThen - executed if a suite-aborting exception is thrown.

  • onCompletedThen - executed whether the result is an Outcome or a thrown suite-aborting exception.

For example, if you want to perform an action if a test fails, you'd register the callback using onFailedThen, like this:

// Your implementation
override def withFixture(test: NoArgAsyncTest) = {

 // Perform setup here

 val futureOutcome = super.withFixture(test) // Invoke the test function

 futureOutcome onFailedThen { ex =>
   // perform action that you want to occur
   // only if a test fails here
 }
}

Note that all callback registration methods, such as onFailedThen used in the previous example, return a new FutureOutcome that won't complete until the the original FutureOutcome and the callback has completed. If the callback throws an exception, the resulting FutureOutcome will represent that exception. For example, if a FutureOutcome results in Failed, but a callback registered on that FutureOutcome with onFailedThen throws TestPendingException, the result of the FutureOutcome returned by onFailedThen will be Pending.

Lastly, if you want to change the outcome in some way in withFixture, you'll need to use the change method of FutureOutcome, like this:

// Your implementation
override def withFixture(test: NoArgAsyncTest) = {

 // Perform setup here

 val futureOutcome = super.withFixture(test) // Invoke the test function

 futureOutcome change { outcome =>
   // transform the outcome into a new outcome here
 }
}
trait Suite
trait Serializable
trait TripleEquals
trait TripleEqualsSupport
class Object
trait Matchable
class Any

Type members

Classlikes

trait NoArgAsyncTest extends () => FutureOutcome with TestData

A test function taking no arguments and returning a FutureOutcome.

A test function taking no arguments and returning a FutureOutcome.

For more detail and examples, see the relevant section in the documentation for trait AsyncFlatSpec.

Inherited classlikes

class CheckingEqualizer[L](val leftSide: L)

Class used via an implicit conversion to enable two objects to be compared with === and !== with a Boolean result and an enforced type constraint between two object types. For example:

Class used via an implicit conversion to enable two objects to be compared with === and !== with a Boolean result and an enforced type constraint between two object types. For example:

assert(a === b)
assert(c !== d)

You can also check numeric values against another with a tolerance. Here are some examples:

assert(a === (2.0 +- 0.1))
assert(c !== (2.0 +- 0.1))
Value parameters:
leftSide

An object to convert to Equalizer, which represents the value on the left side of a === or !== invocation.

Inherited from:
TripleEqualsSupport
class Equalizer[L](val leftSide: L)

Class used via an implicit conversion to enable any two objects to be compared with === and !== with a Boolean result and no enforced type constraint between two object types. For example:

Class used via an implicit conversion to enable any two objects to be compared with === and !== with a Boolean result and no enforced type constraint between two object types. For example:

assert(a === b)
assert(c !== d)

You can also check numeric values against another with a tolerance. Here are some examples:

assert(a === (2.0 +- 0.1))
assert(c !== (2.0 +- 0.1))
Value parameters:
leftSide

An object to convert to Equalizer, which represents the value on the left side of a === or !== invocation.

Inherited from:
TripleEqualsSupport
class ResultOfCompleteInvocation[T](futuristicBlock: => T, futuristic: Futuristic[T])

Class that provides the lastly method of the complete-lastly syntax.

Class that provides the lastly method of the complete-lastly syntax.

Value parameters:
futuristic

the futuristic typeclass instance

futuristicBlock

a by-name that produces a futuristic type

Inherited from:
CompleteLastly
Inherited from:
Assertions

Value members

Concrete methods

override protected def runTest(testName: String, args: Args): Status

Run an async test.

Run an async test.

This method is redefine in this trait solely to narrow its contract. Subclasses must implement this method to call the withFixture(NoArgAsyncTest) method, which is defined in this trait.

This trait's implementation of this method simply returns SucceededStatus and has no other effect.

Value parameters:
args

the Args for this run

testName

the name of one async test to execute.

Returns:

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

Throws:
NullArgumentException

if either testName or args is null.

Definition Classes

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, register a callback on the resulting FutureOutcome to perform any clean up needed after the test completes. Because the NoArgAsyncTest 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 FixtureAsyncTestSuite.

This trait's implementation of runTest invokes this method for each test, passing in a NoArgAsyncTest whose apply method will execute the code of the test and returns its result.

This trait's implementation of this method simply invokes the passed NoArgAsyncTest function.

Value parameters:
test

the no-arg async test function to run with a fixture

Inherited methods

def !==[T](right: Spread[T]): TripleEqualsInvocationOnSpread[T]

Returns a TripleEqualsInvocationOnSpread[T], given an Spread[T], to facilitate the “<left> should !== (<pivot> +- <tolerance>)” syntax of Matchers.

Returns a TripleEqualsInvocationOnSpread[T], given an Spread[T], to facilitate the “<left> should !== (<pivot> +- <tolerance>)” syntax of Matchers.

Value parameters:
right

the Spread[T] against which to compare the left-hand value

Returns:

a TripleEqualsInvocationOnSpread wrapping the passed Spread[T] value, with expectingEqual set to false.

Inherited from:
TripleEqualsSupport
def !==(right: Null): TripleEqualsInvocation[Null]

Returns a TripleEqualsInvocation[Null], given a null reference, to facilitate the “<left> should !== null” syntax of Matchers.

Returns a TripleEqualsInvocation[Null], given a null reference, to facilitate the “<left> should !== null” syntax of Matchers.

Value parameters:
right

a null reference

Returns:

a TripleEqualsInvocation wrapping the passed null value, with expectingEqual set to false.

Inherited from:
TripleEqualsSupport
def !==[T](right: T): TripleEqualsInvocation[T]

Returns a TripleEqualsInvocation[T], given an object of type T, to facilitate the “<left> should !== <right>” syntax of Matchers.

Returns a TripleEqualsInvocation[T], given an object of type T, to facilitate the “<left> should !== <right>” syntax of Matchers.

Value parameters:
right

the right-hand side value for an equality assertion

Returns:

a TripleEqualsInvocation wrapping the passed right value, with expectingEqual set to false.

Inherited from:
TripleEqualsSupport
def ===[T](right: Spread[T]): TripleEqualsInvocationOnSpread[T]

Returns a TripleEqualsInvocationOnSpread[T], given an Spread[T], to facilitate the “<left> should === (<pivot> +- <tolerance>)” syntax of Matchers.

Returns a TripleEqualsInvocationOnSpread[T], given an Spread[T], to facilitate the “<left> should === (<pivot> +- <tolerance>)” syntax of Matchers.

Value parameters:
right

the Spread[T] against which to compare the left-hand value

Returns:

a TripleEqualsInvocationOnSpread wrapping the passed Spread[T] value, with expectingEqual set to true.

Inherited from:
TripleEqualsSupport
def ===(right: Null): TripleEqualsInvocation[Null]

Returns a TripleEqualsInvocation[Null], given a null reference, to facilitate the “<left> should === null” syntax of Matchers.

Returns a TripleEqualsInvocation[Null], given a null reference, to facilitate the “<left> should === null” syntax of Matchers.

Value parameters:
right

a null reference

Returns:

a TripleEqualsInvocation wrapping the passed null value, with expectingEqual set to true.

Inherited from:
TripleEqualsSupport
def ===[T](right: T): TripleEqualsInvocation[T]

Returns a TripleEqualsInvocation[T], given an object of type T, to facilitate the “<left> should === <right>” syntax of Matchers.

Returns a TripleEqualsInvocation[T], given an object of type T, to facilitate the “<left> should === <right>” syntax of Matchers.

Value parameters:
right

the right-hand side value for an equality assertion

Returns:

a TripleEqualsInvocation wrapping the passed right value, with expectingEqual set to true.

Inherited from:
TripleEqualsSupport
inline def assert(inline condition: Boolean, clue: Any)(implicit prettifier: Prettifier, pos: Position, use: UseDefaultAssertions.type): Assertion

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 a helpful error message appended with the String obtained by invoking toString on the specified clue as the exception's detail message.

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 a helpful error message appended with the String obtained by invoking toString on the specified clue as the exception's detail message.

This method is implemented in terms of a Scala macro that will generate a more helpful error message for expressions of this form:

  • assert(a == b, "a good clue")

  • assert(a != b, "a good clue")

  • assert(a === b, "a good clue")

  • assert(a !== b, "a good clue")

  • assert(a > b, "a good clue")

  • assert(a >= b, "a good clue")

  • assert(a < b, "a good clue")

  • assert(a <= b, "a good clue")

  • assert(a startsWith "prefix", "a good clue")

  • assert(a endsWith "postfix", "a good clue")

  • assert(a contains "something", "a good clue")

  • assert(a eq b, "a good clue")

  • assert(a ne b, "a good clue")

  • assert(a > 0 && b > 5, "a good clue")

  • assert(a > 0 || b > 5, "a good clue")

  • assert(a.isEmpty, "a good clue")

  • assert(!a.isEmpty, "a good clue")

  • assert(a.isInstanceOf[String], "a good clue")

  • assert(a.length == 8, "a good clue")

  • assert(a.size == 8, "a good clue")

  • assert(a.exists(_ == 8), "a good clue")

At this time, any other form of expression will just get a TestFailedException with message saying the given expression was false. In the future, we will enhance this macro to give helpful error messages in more situations. In ScalaTest 2.0, however, this behavior was sufficient to allow the === that returns Boolean to be the default in tests. This makes === consistent between tests and production code.

Value parameters:
clue

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

condition

the boolean condition to assert

Throws:
NullArgumentException

if message is null.

TestFailedException

if the condition is false.

Inherited from:
Assertions
inline def assert(inline condition: Boolean)(implicit prettifier: Prettifier, pos: Position, use: UseDefaultAssertions.type): Assertion

Assert that a boolean condition is true. If the condition is true, this method returns normally. Else, it throws TestFailedException.

Assert that a boolean condition is true. If the condition is true, this method returns normally. Else, it throws TestFailedException.

This method is implemented in terms of a Scala macro that will generate a more helpful error message for expressions of this form:

  • assert(a == b)

  • assert(a != b)

  • assert(a === b)

  • assert(a !== b)

  • assert(a > b)

  • assert(a >= b)

  • assert(a < b)

  • assert(a <= b)

  • assert(a startsWith "prefix")

  • assert(a endsWith "postfix")

  • assert(a contains "something")

  • assert(a eq b)

  • assert(a ne b)

  • assert(a > 0 && b > 5)

  • assert(a > 0 || b > 5)

  • assert(a.isEmpty)

  • assert(!a.isEmpty)

  • assert(a.isInstanceOf[String])

  • assert(a.length == 8)

  • assert(a.size == 8)

  • assert(a.exists(_ == 8))

At this time, any other form of expression will get a TestFailedException with message saying the given expression was false. In the future, we will enhance this macro to give helpful error messages in more situations. In ScalaTest 2.0, however, this behavior was sufficient to allow the === that returns Boolean to be the default in tests. This makes === consistent between tests and production code.

Value parameters:
condition

the boolean condition to assert

Throws:
TestFailedException

if the condition is false.

Inherited from:
Assertions
transparent inline def assertCompiles(inline code: String): Assertion

Asserts that a given string snippet of code passes both the Scala parser and type checker.

Asserts that a given string snippet of code passes both the Scala parser and type checker.

You can use this to make sure a snippet of code compiles:

assertCompiles("val a: Int = 1")

Although assertCompiles is implemented with a macro that determines at compile time whether the snippet of code represented by the passed string compiles, errors (i.e., snippets of code that do not compile) are reported as test failures at runtime.

Value parameters:
code

the snippet of code that should compile

Inherited from:
Assertions
transparent inline def assertDoesNotCompile(inline code: String): Assertion

Asserts that a given string snippet of code does not pass either the Scala parser or type checker.

Asserts that a given string snippet of code does not pass either the Scala parser or type checker.

Often when creating libraries you may wish to ensure that certain arrangements of code that represent potential “user errors” do not compile, so that your library is more error resistant. ScalaTest's Assertions trait includes the following syntax for that purpose:

assertDoesNotCompile("val a: String = \"a string")

Although assertDoesNotCompile is implemented with a macro that determines at compile time whether the snippet of code represented by the passed string doesn't compile, errors (i.e., snippets of code that do compile) are reported as test failures at runtime.

Note that the difference between assertTypeError and assertDoesNotCompile is that assertDoesNotCompile will succeed if the given code does not compile for any reason, whereas assertTypeError will only succeed if the given code does not compile because of a type error. If the given code does not compile because of a syntax error, for example, assertDoesNotCompile will return normally but assertTypeError will throw a TestFailedException.

Value parameters:
code

the snippet of code that should not type check

Inherited from:
Assertions
inline def assertResult[L, R](expected: L)(actual: R)(implicit prettifier: Prettifier, caneq: CanEqual[L, R]): Assertion

Assert that the value passed as expected equals the value passed as actual. If the actual value equals the expected value (as determined by ==), assertResult returns normally. Else, assertResult throws a TestFailedException whose detail message includes the expected and actual values.

Assert that the value passed as expected equals the value passed as actual. If the actual value equals the expected value (as determined by ==), assertResult returns normally. Else, assertResult throws a TestFailedException whose detail message includes the expected and actual values.

Value parameters:
actual

the actual value, which should equal the passed expected value

expected

the expected value

Throws:
TestFailedException

if the passed actual value does not equal the passed expected value.

Inherited from:
Assertions
inline def assertResult[L, R](expected: L, clue: Any)(actual: R)(implicit prettifier: Prettifier, caneq: CanEqual[L, R]): Assertion

Assert that the value passed as expected equals the value passed as actual. If the actual equals the expected (as determined by ==), assertResult returns normally. Else, if actual is not equal to expected, assertResult throws a TestFailedException whose detail message includes the expected and actual values, as well as the String obtained by invoking toString on the passed clue.

Assert that the value passed as expected equals the value passed as actual. If the actual equals the expected (as determined by ==), assertResult returns normally. Else, if actual is not equal to expected, assertResult throws a TestFailedException whose detail message includes the expected and actual values, as well as the String obtained by invoking toString on the passed clue.

Value parameters:
actual

the actual value, which should equal the passed expected value

clue

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

expected

the expected value

Throws:
TestFailedException

if the passed actual value does not equal the passed expected value.

Inherited from:
Assertions
inline def assertThrows[T <: AnyRef](f: => Any)(implicit classTag: ClassTag[T]): Assertion

Ensure that an expected exception is 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 Succeeded. Else, whether the passed function returns normally or completes abruptly with a different exception, this method throws TestFailedException.

Ensure that an expected exception is 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 Succeeded. 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.

Also note that the difference between this method and intercept is that this method does not return the expected exception, so it does not let you perform further assertions on that exception. Instead, this method returns Succeeded, which means it can serve as the last statement in an async- or safe-style suite. It also indicates to the reader of the code that nothing further is expected about the thrown exception other than its type. The recommended usage is to use assertThrows by default, intercept only when you need to inspect the caught exception further.

Value parameters:
classTag

an implicit ClassTag representing the type of the specified type parameter.

f

the function value that should throw the expected exception

Returns:

the Succeeded singleton, if an exception of the expected type is thrown

Throws:
TestFailedException

if the passed function does not complete abruptly with an exception that's an instance of the specified type.

Inherited from:
Assertions
transparent inline def assertTypeError(inline code: String): Assertion

Asserts that a given string snippet of code does not pass the Scala type checker, failing if the given snippet does not pass the Scala parser.

Asserts that a given string snippet of code does not pass the Scala type checker, failing if the given snippet does not pass the Scala parser.

Often when creating libraries you may wish to ensure that certain arrangements of code that represent potential “user errors” do not compile, so that your library is more error resistant. ScalaTest's Assertions trait includes the following syntax for that purpose:

assertTypeError("val a: String = 1")

Although assertTypeError is implemented with a macro that determines at compile time whether the snippet of code represented by the passed string type checks, errors (i.e., snippets of code that do type check) are reported as test failures at runtime.

Note that the difference between assertTypeError and assertDoesNotCompile is that assertDoesNotCompile will succeed if the given code does not compile for any reason, whereas assertTypeError will only succeed if the given code does not compile because of a type error. If the given code does not compile because of a syntax error, for example, assertDoesNotCompile will return normally but assertTypeError will throw a TestFailedException.

Value parameters:
code

the snippet of code that should not type check

Inherited from:
Assertions
inline def assume(inline condition: Boolean, clue: Any)(implicit prettifier: Prettifier, pos: Position, use: UseDefaultAssertions.type): Assertion

Assume that a boolean condition, described in String message, is true. If the condition is true, this method returns normally. Else, it throws TestCanceledException with a helpful error message appended with String obtained by invoking toString on the specified clue as the exception's detail message.

Assume that a boolean condition, described in String message, is true. If the condition is true, this method returns normally. Else, it throws TestCanceledException with a helpful error message appended with String obtained by invoking toString on the specified clue as the exception's detail message.

This method is implemented in terms of a Scala macro that will generate a more helpful error message for expressions of this form:

  • assume(a == b, "a good clue")

  • assume(a != b, "a good clue")

  • assume(a === b, "a good clue")

  • assume(a !== b, "a good clue")

  • assume(a > b, "a good clue")

  • assume(a >= b, "a good clue")

  • assume(a < b, "a good clue")

  • assume(a <= b, "a good clue")

  • assume(a startsWith "prefix", "a good clue")

  • assume(a endsWith "postfix", "a good clue")

  • assume(a contains "something", "a good clue")

  • assume(a eq b, "a good clue")

  • assume(a ne b, "a good clue")

  • assume(a > 0 && b > 5, "a good clue")

  • assume(a > 0 || b > 5, "a good clue")

  • assume(a.isEmpty, "a good clue")

  • assume(!a.isEmpty, "a good clue")

  • assume(a.isInstanceOf[String], "a good clue")

  • assume(a.length == 8, "a good clue")

  • assume(a.size == 8, "a good clue")

  • assume(a.exists(_ == 8), "a good clue")

At this time, any other form of expression will just get a TestCanceledException with message saying the given expression was false. In the future, we will enhance this macro to give helpful error messages in more situations. In ScalaTest 2.0, however, this behavior was sufficient to allow the === that returns Boolean to be the default in tests. This makes === consistent between tests and production code.

Value parameters:
clue

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

condition

the boolean condition to assume

Throws:
NullArgumentException

if message is null.

TestCanceledException

if the condition is false.

Inherited from:
Assertions
inline def assume(inline condition: Boolean)(implicit prettifier: Prettifier, pos: Position, use: UseDefaultAssertions.type): Assertion

Assume that a boolean condition is true. If the condition is true, this method returns normally. Else, it throws TestCanceledException.

Assume that a boolean condition is true. If the condition is true, this method returns normally. Else, it throws TestCanceledException.

This method is implemented in terms of a Scala macro that will generate a more helpful error message for expressions of this form:

  • assume(a == b)

  • assume(a != b)

  • assume(a === b)

  • assume(a !== b)

  • assume(a > b)

  • assume(a >= b)

  • assume(a < b)

  • assume(a <= b)

  • assume(a startsWith "prefix")

  • assume(a endsWith "postfix")

  • assume(a contains "something")

  • assume(a eq b)

  • assume(a ne b)

  • assume(a > 0 && b > 5)

  • assume(a > 0 || b > 5)

  • assume(a.isEmpty)

  • assume(!a.isEmpty)

  • assume(a.isInstanceOf[String])

  • assume(a.length == 8)

  • assume(a.size == 8)

  • assume(a.exists(_ == 8))

At this time, any other form of expression will just get a TestCanceledException with message saying the given expression was false. In the future, we will enhance this macro to give helpful error messages in more situations. In ScalaTest 2.0, however, this behavior was sufficient to allow the === that returns Boolean to be the default in tests. This makes === consistent between tests and production code.

Value parameters:
condition

the boolean condition to assume

Throws:
TestCanceledException

if the condition is false.

Inherited from:
Assertions
inline def cancel(cause: Throwable): Nothing

Throws TestCanceledException, with the passed Throwable cause, to indicate a test failed. The getMessage method of the thrown TestCanceledException will return cause.toString.

Throws TestCanceledException, with the passed Throwable cause, to indicate a test failed. The getMessage method of the thrown TestCanceledException will return cause.toString.

Value parameters:
cause

a Throwable that indicates the cause of the cancellation.

Throws:
NullArgumentException

if cause is null

Inherited from:
Assertions
inline def cancel(message: String, cause: Throwable): Nothing

Throws TestCanceledException, with the passed String message as the exception's detail message and Throwable cause, to indicate a test failed.

Throws TestCanceledException, with the passed String message as the exception's detail message and Throwable cause, to indicate a test failed.

Value parameters:
cause

A Throwable that indicates the cause of the failure.

message

A message describing the failure.

Throws:
NullArgumentException

if message or cause is null

Inherited from:
Assertions
inline def cancel(message: String): Nothing

Throws TestCanceledException, with the passed String message as the exception's detail message, to indicate a test was canceled.

Throws TestCanceledException, with the passed String message as the exception's detail message, to indicate a test was canceled.

Value parameters:
message

A message describing the cancellation.

Throws:
NullArgumentException

if message is null

Inherited from:
Assertions
inline def cancel(): Nothing

Throws TestCanceledException to indicate a test was canceled.

Throws TestCanceledException to indicate a test was canceled.

Inherited from:
Assertions
def complete[T](completeBlock: => T)(implicit futuristic: Futuristic[T]): ResultOfCompleteInvocation[T]

Registers a block of code that produces any "futuristic" type (any type F for which an implicit Futuristic[F] instance is implicitly available), returning an object that offers a lastly method.

Registers a block of code that produces any "futuristic" type (any type F for which an implicit Futuristic[F] instance is implicitly available), returning an object that offers a lastly method.

See the main documentation for trait CompleteLastly for more detail.

Value parameters:
completeBlock

cleanup code to execute whether the code passed to complete throws an exception or succesfully returns a futuristic value.

Inherited from:
CompleteLastly
override def convertEquivalenceToAToBConstraint[A, B](equivalenceOfB: Equivalence[B])(implicit ev: A <:< B): CanEqual[A, B]
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
override def convertEquivalenceToBToAConstraint[A, B](equivalenceOfA: Equivalence[A])(implicit ev: B <:< A): CanEqual[A, B]
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
override def convertToCheckingEqualizer[T](left: T): CheckingEqualizer[T]
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
def defaultEquality[A]: Equality[A]

Returns an Equality[A] for any type A that determines equality by first calling .deep on any Array (on either the left or right side), then comparing the resulting objects with ==.

Returns an Equality[A] for any type A that determines equality by first calling .deep on any Array (on either the left or right side), then comparing the resulting objects with ==.

Returns:

a default Equality for type A

Inherited from:
TripleEqualsSupport
final def execute(testName: String, configMap: ConfigMap, color: Boolean, durations: Boolean, shortstacks: Boolean, fullstacks: Boolean, stats: Boolean): Unit

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

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

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

The testName parameter

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

scala> (new ExampleSuite).execute()

(The above syntax actually invokes the overloaded parameterless form of execute, which calls this form with its default parameter values.) To run just the test named "my favorite test" in a suite from the Scala interpreter, you would write:

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

Or:

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

The configMap parameter

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

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

The color parameter

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

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

The durations parameter

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

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

The shortstacks and fullstacks parameters

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

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

For full stack traces, set fullstacks to true:

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

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

The stats parameter

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

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

To summarize, this method will pass to run:

  • testName - None if this method's testName parameter is left at its default value of null, else Some(testName).

  • reporter - a reporter that prints to the standard output

  • stopper - a Stopper whose apply method always returns false

  • filter - a Filter constructed with None for tagsToInclude and Set() for tagsToExclude

  • configMap - the configMap passed to this method

  • distributor - None

  • tracker - a new Tracker

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

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

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

Value parameters:
color

a boolean that configures whether output is printed in color

configMap

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

durations

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

fullstacks

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

shortstacks

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

stats

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

testName

the name of one test to run.

Throws:
IllegalArgumentException

if testName is defined, but no test with the specified test name exists in this Suite

NullArgumentException

if the passed configMap parameter is null.

Inherited from:
Suite
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 and any tests that are exluded by the passed Filter

  • the sum of the values obtained by invoking expectedTestCount on every nested Suite contained in nestedSuites

Value parameters:
filter

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

Inherited from:
Suite
inline def fail(cause: Throwable): Nothing

Throws TestFailedException, with the passed Throwable cause, to indicate a test failed. The getMessage method of the thrown TestFailedException will return cause.toString.

Throws TestFailedException, with the passed Throwable cause, to indicate a test failed. The getMessage method of the thrown TestFailedException will return cause.toString.

Value parameters:
cause

a Throwable that indicates the cause of the failure.

Throws:
NullArgumentException

if cause is null

Inherited from:
Assertions
inline 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.

Value parameters:
cause

A Throwable that indicates the cause of the failure.

message

A message describing the failure.

Throws:
NullArgumentException

if message or cause is null

Inherited from:
Assertions
inline 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.

Value parameters:
message

A message describing the failure.

Throws:
NullArgumentException

if message is null

Inherited from:
Assertions
inline def fail(): Nothing

Throws TestFailedException to indicate a test failed.

Throws TestFailedException to indicate a test failed.

Inherited from:
Assertions
inline def intercept[T <: AnyRef](f: => Any)(implicit classTag: ClassTag[T]): T

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.

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.

Also note that the difference between this method and assertThrows is that this method returns the expected exception, so it lets you perform further assertions on that exception. By contrast, the assertThrows method returns Succeeded, which means it can serve as the last statement in an async- or safe-style suite. assertThrows also indicates to the reader of the code that nothing further is expected about the thrown exception other than its type. The recommended usage is to use assertThrows by default, intercept only when you need to inspect the caught exception further.

Value parameters:
classTag

an implicit ClassTag representing the type of the specified type parameter.

f

the function value that should throw the expected exception

Returns:

the intercepted exception, if it is of the expected type

Throws:
TestFailedException

if the passed function does not complete abruptly with an exception that's an instance of the specified type.

Inherited from:
Assertions
override def lowPriorityTypeCheckedConstraint[A, B](implicit equivalenceOfB: Equivalence[B], ev: A <:< B): CanEqual[A, B]
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
def nestedSuites: IndexedSeq[Suite]

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

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

Inherited from:
Suite
def pending: Assertion & PendingStatement

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 FunSpec 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.

Inherited from:
Assertions
inline def pendingUntilFixed(f: => Unit): Assertion & PendingStatement

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.

Value parameters:
f

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

Throws:
TestPendingException

if the passed block of code completes abruptly with an Exception or AssertionError

Inherited from:
Assertions
def recoverToExceptionIf[T <: AnyRef](future: Future[Any])(implicit classTag: ClassTag[T], exCtx: ExecutionContext, pos: Position): Future[T]

Transforms a future of any type into a Future[T], where T is a given expected exception type, which succeeds if the given future completes with a Failure containing the specified exception type.

Transforms a future of any type into a Future[T], where T is a given expected exception type, which succeeds if the given future completes with a Failure containing the specified exception type.

See the main documentation for this trait for more detail and examples.

Value parameters:
future

A future of any type, which you expect to fail with an exception of the specified type T

Returns:

a Future[T] containing on success the expected exception, or containing on failure a TestFailedException

Inherited from:
RecoverMethods
def recoverToSucceededIf[T <: AnyRef](future: Future[Any])(implicit classTag: ClassTag[T], exCtx: ExecutionContext, pos: Position): Future[Assertion]

Transforms a future of any type into a Future[Assertion] that succeeds if the future completes with a Failure containing the specified exception type.

Transforms a future of any type into a Future[Assertion] that succeeds if the future completes with a Failure containing the specified exception type.

See the main documentation for this trait for more detail and examples.

Value parameters:
future

A future of any type, which you expect to fail with an exception of the specified type T

Returns:

a Future[Assertion] containing on success the Succeeded singleton, or containing on failure a TestFailedException

Inherited from:
RecoverMethods
def rerunner: Option[String]

The fully qualified class name of the rerunner to rerun this suite. This implementation will look at this.getClass and see if it is either an accessible Suite, or it has a WrapWith annotation. If so, it returns the fully qualified class name wrapped in a Some, or else it returns None.

The fully qualified class name of the rerunner to rerun this suite. This implementation will look at this.getClass and see if it is either an accessible Suite, or it has a WrapWith annotation. If so, it returns the fully qualified class name wrapped in a Some, or else it returns None.

Inherited from:
Suite
def run(testName: Option[String], args: Args): Status

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

  • runTests

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.)

Value parameters:
args

the Args for this run

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.

Returns:

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

Throws:
IllegalArgumentException

if testName is defined, but no test with the specified test name exists in this Suite

NullArgumentException

if any passed parameter is null.

Inherited from:
Suite
def suiteId: String

A string ID for this Suite that is intended to be unique among all suites reported during a run.

A string ID for this Suite that is intended to be unique among all suites reported during a run.

This trait's implementation of this method returns the fully qualified name of this object's class. Each suite reported during a run will commonly be an instance of a different Suite class, and in such cases, this default implementation of this method will suffice. However, in special cases you may need to override this method to ensure it is unique for each reported suite. For example, if you write a Suite subclass that reads in a file whose name is passed to its constructor and dynamically creates a suite of tests based on the information in that file, you will likely need to override this method in your Suite subclass, perhaps by appending the pathname of the file to the fully qualified class name. That way if you run a suite of tests based on a directory full of these files, you'll have unique suite IDs for each reported suite.

The suite ID is intended to be unique, because ScalaTest does not enforce that it is unique. If it is not unique, then you may not be able to uniquely identify a particular test of a particular suite. This ability is used, for example, to dynamically tag tests as having failed in the previous run when rerunning only failed tests.

Returns:

this Suite object's ID.

Inherited from:
Suite
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.

Inherited from:
Suite
def tags: Map[String, Set[String]]

A Map whose keys are String names of tests that are tagged and whose associated values are the Set of tag names for the test. If a test has no associated tags, its name does not appear as a key in the returned Map. If this Suite contains no tests with tags, this method returns an empty Map.

A Map whose keys are String names of tests that are tagged and whose associated values are the Set of tag names for the test. If a test has no associated tags, its name does not appear as a key in the returned Map. If this Suite contains no tests with 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 test for which a tag annotation is discovered through reflection.

In addition to test methods annotations, this trait's implementation will also auto-tag test methods with class level annotations. For example, if you annotate @Ignore at the class level, all test methods in the class will be auto-annotated with @Ignore.

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 test has no tags, its name should not appear as a key in the returned Map.

Inherited from:
Suite
def testDataFor(testName: String, theConfigMap: ConfigMap): TestData

Provides a TestData instance for the passed test name, given the passed config map.

Provides a TestData instance for the passed test name, given the passed config map.

This method is used to obtain a TestData instance to pass to withFixture(NoArgTest) and withFixture(OneArgTest) and the beforeEach and afterEach methods of trait BeforeAndAfterEach.

Value parameters:
testName

the name of the test for which to return a TestData instance

theConfigMap

the config map to include in the returned TestData

Returns:

a TestData instance for the specified test, which includes the specified config map

Inherited from:
Suite
def testNames: Set[String]

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

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

This trait's implementation of this method returns an empty Set.

Inherited from:
Suite
override def typeCheckedConstraint[A, B](implicit equivalenceOfA: Equivalence[A], ev: B <:< A): CanEqual[A, B]
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
def withClue[T](clue: Any)(fun: => T): T

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).

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
Throws:
NullArgumentException

if the passed clue is null

Inherited from:
Assertions

Deprecated and Inherited methods

@deprecated("The conversionCheckedConstraint method has been deprecated and will be removed in a future version of ScalaTest. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.", "3.1.0")
override def conversionCheckedConstraint[A, B](implicit equivalenceOfA: Equivalence[A], cnv: B => A): CanEqual[A, B]
Deprecated
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
@deprecated("The convertEquivalenceToAToBConversionConstraint method has been deprecated and will be removed in a future version of ScalaTest. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.", "3.1.0")
override def convertEquivalenceToAToBConversionConstraint[A, B](equivalenceOfB: Equivalence[B])(implicit ev: A => B): CanEqual[A, B]
Deprecated
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
@deprecated("The convertEquivalenceToBToAConversionConstraint method has been deprecated and will be removed in a future version of ScalaTest. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.", "3.1.0")
override def convertEquivalenceToBToAConversionConstraint[A, B](equivalenceOfA: Equivalence[A])(implicit ev: B => A): CanEqual[A, B]
Deprecated
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
@deprecated("The lowPriorityConversionCheckedConstraint method has been deprecated and will be removed in a future version of ScalaTest. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.", "3.1.0")
override def lowPriorityConversionCheckedConstraint[A, B](implicit equivalenceOfB: Equivalence[B], cnv: A => B): CanEqual[A, B]
Deprecated
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
@deprecated("The trap method is no longer needed for demos in the REPL, which now abreviates stack traces, and will be removed in a future version of ScalaTest")
def trap[T](f: => T): Throwable

Trap and return any thrown exception that would normally cause a ScalaTest test to fail, or create and return a new RuntimeException indicating no exception is thrown.

Trap and return any thrown exception that would normally cause a ScalaTest test to fail, or create and return a new RuntimeException indicating no exception is thrown.

This method is intended to be used in the Scala interpreter to eliminate large stack traces when trying out ScalaTest assertions and matcher expressions. It is not intended to be used in regular test code. If you want to ensure that a bit of code throws an expected exception, use intercept, not trap. Here's an example interpreter session without trap:

scala> import org.scalatest._
import org.scalatest._

scala> import Matchers._
import Matchers._

scala> val x = 12
a: Int = 12

scala> x shouldEqual 13
org.scalatest.exceptions.TestFailedException: 12 did not equal 13
  at org.scalatest.Assertions$class.newAssertionFailedException(Assertions.scala:449)
  at org.scalatest.Assertions$.newAssertionFailedException(Assertions.scala:1203)
  at org.scalatest.Assertions$AssertionsHelper.macroAssertTrue(Assertions.scala:417)
  at .<init>(<console>:15)
  at .<clinit>(<console>)
  at .<init>(<console>:7)
  at .<clinit>(<console>)
  at $print(<console>)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at scala.tools.nsc.interpreter.IMain$ReadEvalPrint.call(IMain.scala:731)
  at scala.tools.nsc.interpreter.IMain$Request.loadAndRun(IMain.scala:980)
  at scala.tools.nsc.interpreter.IMain.loadAndRunReq$1(IMain.scala:570)
  at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:601)
  at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:565)
  at scala.tools.nsc.interpreter.ILoop.reallyInterpret$1(ILoop.scala:745)
  at scala.tools.nsc.interpreter.ILoop.interpretStartingWith(ILoop.scala:790)
  at scala.tools.nsc.interpreter.ILoop.command(ILoop.scala:702)
  at scala.tools.nsc.interpreter.ILoop.processLine$1(ILoop.scala:566)
  at scala.tools.nsc.interpreter.ILoop.innerLoop$1(ILoop.scala:573)
  at scala.tools.nsc.interpreter.ILoop.loop(ILoop.scala:576)
  at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply$mcZ$sp(ILoop.scala:867)
  at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:822)
  at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:822)
  at scala.tools.nsc.util.ScalaClassLoader$.savingContextLoader(ScalaClassLoader.scala:135)
  at scala.tools.nsc.interpreter.ILoop.process(ILoop.scala:822)
  at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:83)
  at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:96)
  at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:105)
  at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)

That's a pretty tall stack trace. Here's what it looks like when you use trap:

scala> trap { x shouldEqual 13 }
res1: Throwable = org.scalatest.exceptions.TestFailedException: 12 did not equal 13

Much less clutter. Bear in mind, however, that if no exception is thrown by the passed block of code, the trap method will create a new NormalResult (a subclass of Throwable made for this purpose only) and return that. If the result was the Unit value, it will simply say that no exception was thrown:

scala> trap { x shouldEqual 12 }
res2: Throwable = No exception was thrown.

If the passed block of code results in a value other than Unit, the NormalResult's toString will print the value:

scala> trap { "Dude!" }
res3: Throwable = No exception was thrown. Instead, result was: "Dude!"

Although you can access the result value from the NormalResult, its type is Any and therefore not very convenient to use. It is not intended that trap be used in test code. The sole intended use case for trap is decluttering Scala interpreter sessions by eliminating stack traces when executing assertion and matcher expressions.

Deprecated
Inherited from:
Assertions

Inherited fields

final val pipeChar: '|'
Inherited from:
Assertions
final val succeed: Assertion

The Succeeded singleton.

The Succeeded singleton.

You can use succeed to solve a type error when an async test does not end in either Future[Assertion] or Assertion. Because Assertion is a type alias for Succeeded.type, putting succeed at the end of a test body (or at the end of a function being used to map the final future of a test body) will solve the type error.

Inherited from:
Assertions

Deprecated and Inherited fields

@deprecated("The styleName lifecycle method has been deprecated and will be removed in a future version of ScalaTest with no replacement.", "3.1.0")
val styleName: String

The styleName lifecycle method has been deprecated and will be removed in a future version of ScalaTest.

The styleName lifecycle method has been deprecated and will be removed in a future version of ScalaTest.

This method was used to support the chosen styles feature, which was deactivated in 3.1.0. The internal modularization of ScalaTest in 3.2.0 will replace chosen styles as the tool to encourage consistency across a project. We do not plan a replacement for styleName.

Deprecated
Inherited from:
Suite

Extensions

Inherited extensions

extension (x: String)
inline def stripMargin(c: Char): String
Inherited from:
Assertions
extension (x: String)
inline def stripMargin: String
Inherited from:
Assertions

Implicits

Implicits

implicit def convertAssertionToFutureAssertion(assertion: Assertion): Future[Assertion]

Implicitly converts an Assertion to a Future[Assertion].

Implicitly converts an Assertion to a Future[Assertion].

This implicit conversion is used to allow synchronous tests to be included along with asynchronous tests in an AsyncTestSuite. It will be

Value parameters:
assertion

the Assertion to convert

Returns:

a Future[Assertion] that has already completed successfully (containing the Succeeded singleton).

implicit def convertTestDataAssertionFunToTestDataFutureAssertionFun(fun: TestData => Assertion): TestData => Future[Assertion]
implicit def executionContext: ExecutionContext

Inherited implicits

implicit override def convertToEqualizer[T](left: T): Equalizer[T]
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals
implicit override def unconstrainedEquality[A, B](implicit equalityOfA: Equality[A]): CanEqual[A, B]
Definition Classes
TripleEquals -> TripleEqualsSupport
Inherited from:
TripleEquals