scalatestPropSpecDotty/org.scalatest.propspec/PropSpec

PropSpec

@Finders(scala.Array.apply[java.lang.String]("org.scalatest.finders.PropSpecFinder")(scala.reflect.ClassTag.apply[java.lang.String](classOf[java.lang.String])))

class PropSpec extends PropSpecLike

A suite of property-based tests.

Recommended Usage: Class PropSpec is a good fit for teams that want to write tests exclusively in terms of property checks, and is also a good choice for writing the occasional test matrix when a different style trait is chosen as the main unit testing style.

Here's an example PropSpec:

package org.scalatest.examples.propspec

import org.scalatest._
import prop._
import scala.collection.immutable._

class SetSpec extends propspec.PropSpec with TableDrivenPropertyChecks with Matchers {

 val examples =
   Table(
     "set",
     BitSet.empty,
     HashSet.empty[Int],
     TreeSet.empty[Int]
   )

 property("an empty Set should have size 0") {
   forAll(examples) { set =>
     set.size should be (0)
   }
 }

 property("invoking head on an empty set should produce NoSuchElementException") {
   forAll(examples) { set =>
     a [NoSuchElementException] should be thrownBy { set.head }
   }
 }
}

You can run a PropSpec by invoking execute on it. This method, which prints test results to the standard output, is intended to serve as a convenient way to run tests from within the Scala interpreter. For example, to run SetSpec from within the Scala interpreter, you could write:

scala> org.scalatest.run(new SetSpec)

And you would see:

SetSpec:
- an empty Set should have size 0
- invoking head on an empty Set should produce NoSuchElementException

Or, to run just the “an empty Set should have size 0” method, you could pass that test's name, or any unique substring of the name, such as "size 0" or even just "0". Here's an example:

scala> org.scalatest.run(new SetSpec, "size 0")
SetSpec:
- an empty Set should have size 0

You can also pass to execute a config map of key-value pairs, which will be passed down into suites and tests, as well as other parameters that configure the run itself. For more information on running in the Scala interpreter, see the documentation for execute (below) and the ScalaTest shell.

The execute method invokes a run method that takes two parameters. This run method, which actually executes the suite, will usually be invoked by a test runner, such as run, tools.Runner, a build tool, or an IDE.

“property” is a method, defined in PropSpec, which will be invoked by the primary constructor of SetSpec. You specify the name of the test as a string between the parentheses, and the test code itself between curly braces. The test code is a function passed as a by-name parameter to property, which registers it for later execution.

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

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

== Ignored tests ==

To support the common use case of temporarily disabling a test, with the good intention of resurrecting the test at a later time, PropSpec provides registration methods that start with ignore instead of property. Here's an example:

package org.scalatest.examples.suite.ignore

import org.scalatest._
import prop._
import scala.collection.immutable._

class SetSpec extends propspec.PropSpec with TableDrivenPropertyChecks with Matchers {

 val examples =
   Table(
     "set",
     BitSet.empty,
     HashSet.empty[Int],
     TreeSet.empty[Int]
   )

 ignore("an empty Set should have size 0") {
   forAll(examples) { set =>
     set.size should be (0)
   }
 }

 property("invoking head on an empty set should produce NoSuchElementException") {
   forAll(examples) { set =>
     a [NoSuchElementException] should be thrownBy { set.head }
   }
 }
}

If you run this version of SetSuite with:

scala> org.scalatest.run(new SetSpec)

It will run only the second test and report that the first test was ignored:

SetSuite:
- an empty Set should have size 0 !!! IGNORED !!!
- invoking head on an empty Set should produce NoSuchElementException

== Informers ==

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

package org.scalatest.examples.propspec.info

import org.scalatest._
import prop._
import collection.mutable

class SetSpec extends propspec.PropSpec with TableDrivenPropertyChecks with GivenWhenThen {

 val examples =
   Table(
     "set",
     mutable.BitSet.empty,
     mutable.HashSet.empty[Int],
     mutable.LinkedHashSet.empty[Int]
   )

 property("an element can be added to an empty mutable Set") {

   forAll(examples) { set =>

     info("----------------")

     Given("an empty mutable " + set.getClass.getSimpleName)
     assert(set.isEmpty)

     When("an element is added")
     set += 99

     Then("the Set should have size 1")
     assert(set.size === 1)

     And("the Set should contain the added element")
     assert(set.contains(99))
   }
 }
}

If you run this PropSpec from the interpreter, you will see the following output:

scala> org.scalatest.run(new SetSpec)
SetSpec:
- an element can be added to an empty mutable Set
 + ----------------
 + Given an empty mutable BitSet
 + When an element is added
 + Then the Set should have size 1
 + And the Set should contain the added element
 + ----------------
 + Given an empty mutable HashSet
 + When an element is added
 + Then the Set should have size 1
 + And the Set should contain the added element
 + ----------------
 + Given an empty mutable LinkedHashSet
 + When an element is added
 + Then the Set should have size 1
 + And the Set should contain the added element

== Documenters ==

PropSpec also provides a markup method that returns a Documenter, which allows you to send to the Reporter text formatted in Markdown syntax. You can pass the extra information to the Documenter via its apply method. The Documenter will then pass the information to the Reporter via an MarkupProvided event.

Here's an example PropSpec that uses markup:

package org.scalatest.examples.propspec.markup

import org.scalatest._
import prop._
import collection.mutable

class SetSpec extends propspec.PropSpec with TableDrivenPropertyChecks with GivenWhenThen {

 markup { """

Mutable Set
-----------

A set is a collection that contains no duplicate elements.

To implement a concrete mutable set, you need to provide implementations
of the following methods:

   def contains(elem: A): Boolean
   def iterator: Iterator[A]
   def += (elem: A): this.type
   def -= (elem: A): this.type

If you wish that methods like `take`,
`drop`, `filter` return the same kind of set,
you should also override:

   def empty: This

It is also good idea to override methods `foreach` and
`size` for efficiency.

 """ }

 val examples =
   Table(
     "set",
     mutable.BitSet.empty,
     mutable.HashSet.empty[Int],
     mutable.LinkedHashSet.empty[Int]
   )

 property("an element can be added to an empty mutable Set") {

   forAll(examples) { set =>

     info("----------------")

     Given("an empty mutable " + set.getClass.getSimpleName)
     assert(set.isEmpty)

     When("an element is added")
     set += 99

     Then("the Set should have size 1")
     assert(set.size === 1)

     And("the Set should contain the added element")
     assert(set.contains(99))
   }

   markup("This test finished with a **bold** statement!")
 }
}

Although all of ScalaTest's built-in reporters will display the markup text in some form, the HTML reporter will format the markup information into HTML. Thus, the main purpose of markup is to add nicely formatted text to HTML reports. Here's what the above SetSpec would look like in the HTML reporter:

== Notifiers and alerters ==

ScalaTest records text passed to info and markup during tests, and sends the recorded text in the recordedEvents field of test completion events like TestSucceeded and TestFailed. This allows string reporters (like the standard out reporter) to show info and markup text after the test name in a color determined by the outcome of the test. For example, if the test fails, string reporters will show the info and markup text in red. If a test succeeds, string reporters will show the info and markup text in green. While this approach helps the readability of reports, it means that you can't use info to get status updates from long running tests.

To get immediate (i.e., non-recorded) notifications from tests, you can use note (a Notifier) and alert (an Alerter). Here's an example showing the differences:

package org.scalatest.examples.propspec.note

import org.scalatest._
import prop._
import collection.mutable

class SetSpec extends propspec.PropSpec with TableDrivenPropertyChecks {

 val examples =
   Table(
     "set",
     mutable.BitSet.empty,
     mutable.HashSet.empty[Int],
     mutable.LinkedHashSet.empty[Int]
   )

 property("an element can be added to an empty mutable Set") {

   info("info is recorded")
   markup("markup is *also* recorded")
   note("notes are sent immediately")
   alert("alerts are also sent immediately")

   forAll(examples) { set =>

     assert(set.isEmpty)
     set += 99
     assert(set.size === 1)
     assert(set.contains(99))
   }
 }
}

Because note and alert information is sent immediately, it will appear before the test name in string reporters, and its color will be unrelated to the ultimate outcome of the test: note text will always appear in green, alert text will always appear in yellow. Here's an example:

scala> org.scalatest.run(new SetSpec)
SetSpec:
 + notes are sent immediately
 + alerts are also sent immediately
- an element can be added to an empty mutable Set
 + info is recorded
 + markup is *also* recorded

Another example is slowpoke notifications. If you find a test is taking a long time to complete, but you're not sure which test, you can enable slowpoke notifications. ScalaTest will use an Alerter to fire an event whenever a test has been running longer than a specified amount of time.

In summary, use info and markup for text that should form part of the specification output. Use note and alert to send status notifications. (Because the HTML reporter is intended to produce a readable, printable specification, info and markup text will appear in the HTML report, but note and alert text will not.)

== Pending tests ==

A pending test is one that has been given a name but is not yet implemented. The purpose of pending tests is to facilitate a style of testing in which documentation of behavior is sketched out before tests are written to verify that behavior (and often, 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.

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. (The code of a pending test is executed just like any other test.) However, because the test completes abruptly with TestPendingException, the test will be reported as pending, to indicate the actual test, and possibly the functionality, has not yet been implemented.

You can mark tests pending in PropSpec like this:

import org.scalatest._
import prop._
import scala.collection.immutable._

class SetSpec extends propspec.PropSpec with TableDrivenPropertyChecks with Matchers {

 val examples =
   Table(
     "set",
     BitSet.empty,
     HashSet.empty[Int],
     TreeSet.empty[Int]
   )

 property("an empty Set should have size 0") (pending)

 property("invoking head on an empty set should produce NoSuchElementException") {
   forAll(examples) { set =>
     a [NoSuchElementException] should be thrownBy { set.head }
   }
 }
}

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

scala> org.scalatest.run(new SetSuite)

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

SetSuite:
- An empty Set should have size 0 (pending)
- Invoking head on an empty Set should produce NoSuchElementException

One difference between an ignored test and a pending one is that an ignored test is intended to be used during a significant refactorings of the code under test, when tests break and you don't want to spend the time to fix all of them immediately. You can mark some of those broken tests as ignored temporarily, so that you can focus the red bar on just failing tests you actually want to fix immediately. Later you can go back and fix the ignored tests. In other words, by ignoring some failing tests temporarily, you can more easily notice failed tests that you actually want to fix. By contrast, a pending test is intended to be used before a test and/or the code under test is written. Pending indicates you've decided to write a test for a bit of behavior, but either you haven't written the test yet, or have only written part of it, or perhaps you've written the test but don't want to implement the behavior it tests until after you've implemented a different bit of behavior you realized you need first. Thus ignored tests are designed to facilitate refactoring of existing code whereas pending tests are designed to facilitate the creation of new code.

One other difference between ignored and pending tests is that ignored tests are implemented as a test tag that is excluded by default. Thus an ignored test is never executed. By contrast, a pending test is implemented as a test that throws TestPendingException (which is what calling the pending method does). Thus the body of pending tests are executed up until they throw TestPendingException. The reason for this difference is that it enables your unfinished test to send InfoProvided messages to the reporter before it completes abruptly with TestPendingException, as shown in the previous example on Informers that used the GivenWhenThen trait.

== Tagging tests ==

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

package org.scalatest.examples.propspec.tagging

import org.scalatest.Tag

object DbTest extends Tag("com.mycompany.tags.DbTest")

Given these definitions, you could place PropSpec tests into groups with tags like this:

import org.scalatest._
import prop._
import tagobjects.Slow
import scala.collection.immutable._

class SetSpec extends propspec.PropSpec with TableDrivenPropertyChecks with Matchers {

 val examples =
   Table(
     "set",
     BitSet.empty,
     HashSet.empty[Int],
     TreeSet.empty[Int]
   )

 property("an empty Set should have size 0", Slow) {
   forAll(examples) { set =>
     set.size should be (0)
   }
 }

 property("invoking head on an empty set should produce NoSuchElementException",
     Slow, DbTest) {

   forAll(examples) { set =>
     a [NoSuchElementException] should be thrownBy { set.head }
   }
 }
}

This code marks both tests with the org.scalatest.tags.Slow tag, and the second test with the com.mycompany.tags.DbTest tag.

The run method takes a Filter, whose constructor takes an optional Set[String] called tagsToInclude and a Set[String] called tagsToExclude. If tagsToInclude is None, all tests will be run except those those belonging to tags listed in the tagsToExclude Set. If tagsToInclude is defined, only tests belonging to tags mentioned in the tagsToInclude set, and not mentioned in tagsToExclude, will be run.

== Shared fixtures ==

A test fixture is composed of the objects and other artifacts (files, sockets, database connections, etc.) tests use to do their work. When multiple tests need to work with the same fixtures, it is important to try and avoid duplicating the fixture code across those tests. The more code duplication you have in your tests, the greater drag the tests will have on refactoring the actual production code.

ScalaTest recommends three techniques to eliminate such code duplication:

Refactor using Scala
Override withFixture
Mix in a before-and-after trait

Each technique is geared towards helping you reduce code duplication without introducing instance vars, shared mutable objects, or other dependencies between tests. Eliminating shared mutable state across tests will make your test code easier to reason about and more amenable for parallel test execution.

The techniques in PropSpec are identical to those in FunSuite, but with “test” replaced by “property”. The following table summarizes the options with a link to the relevant documentation for trait FunSuite:

Refactor using Scala when different tests need different fixtures.
get-fixture methods	The extract method refactor helps you create a fresh instances of mutable fixture objects in each test that needs them, but doesn't help you clean them up when you're done.
fixture-context objects	By placing fixture methods and fields into traits, you can easily give each test just the newly created fixtures it needs by mixing together traits. Use this technique when you need different combinations of mutable fixture objects in different tests, and don't need to clean up after.
loan-fixture methods	Factor out dupicate code with the loan pattern when different tests need different fixtures that must be cleaned up afterwards.
Override `withFixture` when most or all tests need the same fixture.
`withFixture(NoArgTest)`	The recommended default approach when most or all tests need the same fixture treatment. This general technique allows you, for example, to perform side effects at the beginning and end of all or most tests, transform the outcome of tests, retry tests, make decisions based on test names, tags, or other test data. Use this technique unless: Different tests need different fixtures (refactor using Scala instead) An exception in fixture code should abort the suite, not fail the test (use a before-and-after trait instead) You have objects to pass into tests (override `withFixture(OneArgTest)` instead)
`withFixture(OneArgTest)`	Use when you want to pass the same fixture object or objects as a parameter into all or most tests.
Mix in a before-and-after trait when you want an aborted suite, not a failed test, if the fixture code fails.
`BeforeAndAfter`	Use this boilerplate-buster when you need to perform the same side-effects before and/or after tests, rather than at the beginning or end of tests.
`BeforeAndAfterEach`	Use when you want to stack traits that perform the same side-effects before and/or after tests, rather than at the beginning or end of tests.

==== Using PropSpec to implement a test matrix ====

Using fixture-context objects in a PropSpec is a good way to implement a test matrix. What is the matrix? A test matrix is a series of tests that you need to run on a series of subjects. For example, The Scala API contains many implementations of trait Set. Every implementation must obey the contract of Set. One property of any Set is that an empty Set should have size 0, another is that invoking head on an empty Set should give you a NoSuchElementException, and so on. Already you have a matrix, where rows are the properties and the columns are the set implementations:

	`BitSet`	`HashSet`	`TreeSet`
An empty Set should have size 0	pass	pass	pass
Invoking head on an empty set should produce NoSuchElementException	pass	pass	pass

One way to implement this test matrix is to define a trait to represent the columns (in this case, BitSet, HashSet, and TreeSet) as elements in a single-dimensional Table. Each element in the Table represents one Set implementation. Because different properties may require different fixture instances for those implementations, you can define a trait to hold the examples, like this:

trait SetExamples extends Tables {

 def examples = Table("set", bitSet, hashSet, treeSet)

 def bitSet: BitSet
 def hashSet: HashSet[Int]
 def treeSet: TreeSet[Int]
}

Given this trait, you could provide empty sets in one implementation of SetExamples, and non-empty sets in another. Here's how you might provide empty set examples:

class EmptySetExamples extends SetExamples {
 def bitSet = BitSet.empty
 def hashSet = HashSet.empty[Int]
 def treeSet = TreeSet.empty[Int]
}

And here's how you might provide set examples with one item each:

class SetWithOneItemExamples extends SetExamples {
 def bitSet = BitSet(1)
 def hashSet = HashSet(1)
 def treeSet = TreeSet(1)
}

Armed with these example classes, you can define checks of properties that require empty or non-empty set fixtures by using instances of these classes as fixture-context objects. In other words, the columns of the test matrix are implemented as elements of a one-dimensional table of fixtures, the rows are implemented as property clauses of a PropSpec.

Here's a complete example that checks the two properties mentioned previously:

package org.scalatest.examples.propspec.matrix

import org.scalatest._
import org.scalatest.prop._
import scala.collection.immutable._

trait SetExamples extends Tables {

 def examples = Table("set", bitSet, hashSet, treeSet)

 def bitSet: BitSet
 def hashSet: HashSet[Int]
 def treeSet: TreeSet[Int]
}

class EmptySetExamples extends SetExamples {
 def bitSet = BitSet.empty
 def hashSet = HashSet.empty[Int]
 def treeSet = TreeSet.empty[Int]
}

class SetSpec extends propspec.PropSpec with TableDrivenPropertyChecks with Matchers {

 property("an empty Set should have size 0") {
   new EmptySetExamples {
     forAll(examples) { set =>
       set.size should be (0)
     }
   }
 }

 property("invoking head on an empty set should produce NoSuchElementException") {
   new EmptySetExamples {
     forAll(examples) { set =>
       a [NoSuchElementException] should be thrownBy { set.head }
     }
   }
 }
}

One benefit of this approach is that the compiler will help you when you need to add either a new row or column to the matrix. In either case, you'll need to ensure all cells are checked to get your code to compile.

== Shared tests ==

Sometimes you may want to run the same test code on different fixture objects. That is to say, you may want to write tests that are "shared" by different fixture objects. You accomplish this in a PropSpec in the same way you would do it in a FunSuite, except instead of test you say property, and instead of testsFor you say propertiesFor. For more information, see the Shared tests section of FunSuite's documentation.

trait PropSpecLike

trait Documenting

trait Alerting

trait Notifying

trait Informing

trait TestSuite

trait Suite

trait Serializable

trait Assertions

trait TripleEquals

trait TripleEqualsSupport

class Object

trait Matchable

class Any

Type members

Inherited classlikes

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 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

A test function taking no arguments and returning an Outcome.

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

Inherited from:: TestSuite

Inherited from:: Assertions

Value members

Concrete methods

Returns a user friendly string for this suite, composed of the simple name of the class (possibly simplified further by removing dollar signs if added by the Scala interpeter) and, if this suite contains nested suites, the result of invoking toString on each of the nested suites, separated by commas and surrounded by parentheses.

Returns:: a user-friendly string for this suite
Definition Classes: Any

Inherited methods

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

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

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

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

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

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

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 PropSpec 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.

Inherited from:: PropSpecLike

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

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

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

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

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

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

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

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.

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.

Value parameters:

code: the snippet of code that should not type check

Inherited from:

Assertions

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

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))

Value parameters:

condition: the boolean condition to assume

Throws:

TestCanceledException: if the condition is false.

Inherited from:

Assertions

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

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

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

Throws TestCanceledException to indicate a test was canceled.

Inherited from:: Assertions

Definition Classes: TripleEquals -> TripleEqualsSupport
Inherited from:: TripleEquals

Definition Classes: TripleEquals -> TripleEqualsSupport
Inherited from:: TripleEquals

Definition Classes: TripleEquals -> TripleEqualsSupport
Inherited from:: TripleEquals

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

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

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

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

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

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

Throws TestFailedException to indicate a test failed.

Inherited from:: Assertions

Register a property-based test to ignore, which has the specified name, optional tags, and function value that takes no arguments. This method will register the test for later ignoring via an invocation of one of the run methods. This method exists to make it easy to ignore an existing test by changing the call to test to ignore without deleting or commenting out the actual test code. The test will not be run, but a report will be sent that indicates the test was ignored. The passed test name must not have been registered previously on this PropSpec instance.

Value parameters:

testFun: the test function
testName: the name of the test
testTags: the optional list of tags for this test

Throws:

DuplicateTestNameException: if a test with the same name has been registered previously
NotAllowedException: if testName had been registered previously
TestRegistrationClosedException: if invoked after run has been invoked on this suite

Inherited from:

PropSpecLike

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.

Inherited from:: PropSpecLike

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.

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

Definition Classes: TripleEquals -> TripleEqualsSupport
Inherited from:: TripleEquals

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.

Inherited from:: PropSpecLike

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

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 PropSpec 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.

Inherited from:: PropSpecLike

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

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

Registers shared tests.

This method enables the following syntax for shared tests in a PropSpec:

propertiesFor(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 tests. For examples of shared tests, see the Shared tests section in the main documentation for this trait.

Inherited from:: PropSpecLike

Register a property-based test with the specified name, optional tags, and function value that takes no arguments. This method will register the test for later execution via an invocation of one of the run methods. The passed test name must not have been registered previously on this PropSpec instance.

Value parameters:

testFun: the property function
testName: the name of the property
testTags: the optional list of tags for this property

Throws:

DuplicateTestNameException: if a test with the same name has been registered previously
NotAllowedException: if testName had been registered previously
NullArgumentException: if testName or any passed test tag is null
TestRegistrationClosedException: if invoked after run has been invoked on this suite

Inherited from:

PropSpecLike

Inherited from:: PropSpecLike

Inherited from:: PropSpecLike

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

Definition Classes: PropSpecLike -> Suite
Inherited from:: PropSpecLike

Run a test. This trait's implementation runs the test registered with the name specified by testName.

Value parameters:

args: the Args for this run
testName: the name of one test to run.

Returns:

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

Throws:

IllegalArgumentException: if testName is defined but a test with that name does not exist on this PropSpec
NullArgumentException: if any of testName, reporter, stopper, or configMap is null.

Definition Classes

PropSpecLike -> TestSuite -> Suite

Inherited from:

PropSpecLike

Run zero to many of this PropSpec's tests.

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 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 of the passed parameters is null.

Definition Classes

PropSpecLike -> Suite

Inherited from:

PropSpecLike

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

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

A Map whose keys are String names of tagged tests and whose associated values are the Set of tags for the test. If this PropSpec 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 property 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 org.scalatest.Ignore.

Definition Classes: PropSpecLike -> Suite
Inherited from:: PropSpecLike

Definition Classes: PropSpecLike -> Suite
Inherited from:: PropSpecLike

An immutable Set of test names. If this PropSpec 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.

Definition Classes: PropSpecLike -> Suite
Inherited from:: PropSpecLike

Definition Classes: TripleEquals -> TripleEqualsSupport
Inherited from:: TripleEquals

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

Run the passed test function in the context of a fixture established by this method.

This method should set up the fixture needed by the tests of the current suite, invoke the test function, and if needed, perform any clean up needed after the test completes. Because the NoArgTest function passed to this method takes no parameters, preparing the fixture will require side effects, such as reassigning instance vars in this Suite or initializing a globally accessible external database. If you want to avoid reassigning instance vars you can use FixtureSuite.

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

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

Value parameters:

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

Inherited from:

TestSuite

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")

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")

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")

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")

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")

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

Inherited from:: Assertions

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")

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:: PropSpecLike

Extensions

Inherited extensions

extension (x: String)

Inherited from:: Assertions

extension (x: String)

Inherited from:: Assertions

Implicits

Inherited implicits

Definition Classes: TripleEquals -> TripleEqualsSupport
Inherited from:: TripleEquals

Definition Classes: TripleEquals -> TripleEqualsSupport
Inherited from:: TripleEquals