AsyncFeatureSpecLike

Construct a new instance of this Suite.

This trait's implementation of runTests invokes this method to create a new instance of this Suite for each test. This trait's implementation of this method uses reflection to call this.getClass.newInstance. This approach will succeed only if this Suite's class has a public, no-arg constructor. In most cases this is likely to be true, because to be instantiated by ScalaTest's Runner a Suite needs a public, no-arg constructor. However, this will not be true of any Suite defined as an inner class of another class or trait, because every constructor of an inner class type takes a reference to the enclosing instance. In such cases, and in cases where a Suite class is explicitly defined without a public, no-arg constructor, you will need to override this method to construct a new instance of the Suite in some other way.

Here's an example of how you could override newInstance to construct a new instance of an inner class:

import org.scalatest.Suite

class Outer {
  class InnerSuite extends Suite with OneInstancePerTest {
    def testOne() {}
    def testTwo() {}
    override def newInstance = new InnerSuite
  }
}

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

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.

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.

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.

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.

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 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.

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.

Helper instance used by code generated by macro 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.

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.

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.

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 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, to indicate a test was canceled.

Throws TestCanceledException to indicate a test was canceled.

Implicitly converts a function that takes no parameters and results in Any to a function from FixtureParam to Any, to enable no-arg tests to registered by methods that require a test function that takes a FixtureParam.

Implicitly converts a function that takes no parameters and results in PendingNothing to a function from FixtureParam to Any, to enable pending tests to registered as by-name parameters by methods that require a test function that takes a FixtureParam.

This method makes it possible to write pending tests as simply (pending), without needing to write (fixture => pending).

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

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 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, to indicate a test failed.

Throws TestFailedException to indicate a test failed.

Describe a “subject” being specified and tested by the passed function value. The passed function value may contain more describers (defined with describe) and/or tests (defined with it). This trait's implementation of this method will register the description string and immediately invoke the passed function.

Register a test to ignore, which has the given spec text, optional tags, and test function value that takes no arguments. This method will register the test for later ignoring via an invocation of one of the execute methods. This method exists to make it easy to ignore an existing test by changing the call to it to ignore without deleting or commenting out the actual test code. The test will not be executed, but a report will be sent that indicates the test was ignored. The name of the test will be a concatenation of the text of all surrounding describers, from outside in, and the passed spec text, with one space placed between each item. (See the documenation for testNames for an example.) The resulting test name must not have been registered previously on this FeatureSpec instance.

Returns an Informer that during test execution will forward strings passed to its apply method to the current reporter. If invoked in a constructor, it will register the passed string for forwarding later during test execution. If invoked from inside a scope, it will forward the information to the current reporter immediately. If invoked from inside a test function, it will record the information and forward it to the current reporter only after the test completed, as recordedEvents of the test completed event, such as TestSucceeded. If invoked at any other time, it will print to the standard output. This method can be called safely by any thread.

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.

Returns a Documenter that during test execution will forward strings passed to its apply method to the current reporter. If invoked in a constructor, it will register the passed string for forwarding later during test execution. If invoked from inside a scope, it will forward the information to the current reporter immediately. If invoked from inside a test function, it will record the information and forward it to the current reporter only after the test completed, as recordedEvents of the test completed event, such as TestSucceeded. If invoked at any other time, it will print to the standard output. This method can be called safely by any thread.

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.

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

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.

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.

Register an ignored test, note that an ignored test will not be executed, but it will cause a TestIgnored event to be fired.

Register a test.

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.

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.)

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

If the passed distributor is None, this trait's implementation of this method invokes run on each nested Suite in the List obtained by invoking nestedSuites. If a nested Suite's run method completes abruptly with an exception, this trait's implementation of this method reports that the Suite aborted and attempts to run the next nested Suite. If the passed distributor is defined, this trait's implementation puts each nested Suite into the Distributor contained in the Some, in the order in which the Suites appear in the List returned by nestedSuites, passing in a new Tracker obtained by invoking nextTracker on the Tracker passed to this method.

Implementations of this method are responsible for ensuring SuiteStarting events are fired to the Reporter before executing any nested Suite, and either SuiteCompleted or SuiteAborted after executing any nested Suite.

Modifies the behavior of super.runTest to facilitate running each test in its own instance of this Suite's class.

This trait's implementation of runTest uses the runTestInNewInstance flag of the passed Args object to determine whether this instance is the general instance responsible for running all tests in the suite (runTestInNewInstance is true), or a test-specific instance responsible for running just one test (runTestInNewInstance is false). Note that these Boolean values are reverse those used by runTests, because runTests always inverts the Boolean value of runTestInNewInstance when invoking runTest.

If runTestInNewInstance is true, this trait's implementation of this method creates a new instance of this class (by invoking newInstance on itself), then invokes run on the new instance, passing in testName, wrapped in a Some, and args unchanged. (I.e., the Args object passed to runTest is forwarded as is to run on the new instance, including with runTestInNewInstance set.) If the invocation of either newInstance on this Suite or run on a newly created instance of this Suite completes abruptly with an exception, then this runTests method will complete abruptly with the same exception.

If runTestInNewInstance is false, this trait's implementation of this method simply invokes super.runTest, passing along the same testName and args objects.

Modifies the behavior of super.runTests to facilitate running each test in its own instance of this Suite's class.

This trait's implementation of runTest uses the runTestInNewInstance flag of the passed Args object to determine whether this instance is the general instance responsible for running all tests in the suite (runTestInNewInstance is false), or a test-specific instance responsible for running just one test (runTestInNewInstance is true). Note that these Boolean values are reverse those used by runTest, because runTests always inverts the Boolean value of runTestInNewInstance when invoking runTest.

If runTestInNewInstance is false, this trait's implementation of this method will invoke super.runTests, passing along testName and args, but with the runTestInNewInstance flag set to true. By setting runTestInNewInstance to true, runTests is telling runTest to create a new instance to run each test.

If runTestInNewInstance is true, this trait's implementation of this method will invoke runTest directly, passing in testName.get and the args object, with the runTestInNewInstance flag set to false. By setting runTestInNewInstance to false, runTests is telling runTest that this is the test-specific instance, so it should just run the specified test.

Register a test with the given spec text, optional tags, and test function value that takes no arguments. An invocation of this method is called an “example.”

This method will register the test for later execution via an invocation of one of the execute methods. The name of the test will be a concatenation of the text of all surrounding describers, from outside in, and the passed spec text, with one space placed between each item. (See the documenation for testNames for an example.) The resulting test name must not have been registered previously on this FeatureSpec instance.

Registers shared scenarios.

This method enables the following syntax for shared scenarios in a FeatureSpec:

scenariosFor(nonEmptyStack(lastValuePushed))

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

Suite style name.

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.

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.

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

In addition, this trait's implementation will also auto-tag tests 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.

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.

An immutable Set of test names. If this FeatureSpec 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. Each test's name is composed of the concatenation of the text of each surrounding describer, in order from outside in, and the text of the example itself, with all components separated by a space.

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.

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

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

This method should set up the fixture needed by the tests of the current suite, invoke the test function, and if needed, perform any clean up needed after the test completes. Because the NoArgTest function passed to this method takes no parameters, preparing the fixture will require side effects, such as initializing an external database.