ConfigMapWrapperSuite

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))

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))

Returns the result obtained from invoking expectedTestCount on an instance of the wrapped suite, constructed by passing an empty config map to its constructor, passing into the wrapped suite's expectedTestCount method the specified Filter.

Returns the result obtained from invoking nestedSuites on an instance of the wrapped suite, constructed by passing an empty config map to its constructor.

Constructs a new instance of the suite to wrap, whose Class is passed to this suite's constructor, passing in the specified config map, and invokes run on that new instance, passing in the same arguments passed to this method.

Returns the result obtained from invoking tags on an instance of the wrapped suite, constructed by passing an empty config map to its constructor.

Returns the result obtained from invoking testNames on an instance of the wrapped suite, constructed by passing an empty config map to its constructor.

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

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

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

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

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

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

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.

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.

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.

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.

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 ==.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.