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/*
 * Copyright 2001-2013 Artima, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.scalatest.freespec

import org.scalatest.{Suite, Finders}

/**
 * Facilitates a “behavior-driven” style of development (BDD), in which tests
 * are nested inside text clauses denoted with the dash operator (-).
 *
 * 

* AnyFreeSpec is so named because unlike classes such as AnyWordSpec, AnyFlatSpec, and AnyFunSpec, * it is enforces no structure on the text. You are free to compose text however you like. (A AnyFreeSpec is like free-verse poetry as * opposed to a sonnet or haiku, which defines a structure for the text of the poem.) *

* *
* Recommended Usage: * Because it gives absolute freedom (and no guidance) on how specification text should be written, AnyFreeSpec is a good choice for teams experienced * with BDD and able to agree on how to structure the specification text. *
* *

* Here's an example AnyFreeSpec: *

* *
 * package org.scalatest.examples.freespec
 * 
 * import org.scalatest.freespec.AnyFreeSpec
 * 
 * class SetSpec extends AnyFreeSpec {
 * 
 *   "A Set" - {
 *     "when empty" - {
 *       "should have size 0" in {
 *         assert(Set.empty.size === 0)
 *       }
 *       
 *       "should produce NoSuchElementException when head is invoked" in {
 *         assertThrows[NoSuchElementException] {
 *           Set.empty.head
 *         }
 *       }
 *     }
 *   }
 * }
 * 
* *

* In a AnyFreeSpec you write a test with a string followed by in and the body of the * test in curly braces, like this: *

* *
 * "should have size 0" in {
 *   // ...
 * }
 * 
* *

* You can nest a test inside any number of description clauses, which you write with a string followed by a dash character * and a block, like this: *

* *
 * "A Set" - {
 *   // ...
 * }
 * 
* *

* You can nest description clauses as deeply as you want. Because the description clause is denoted with an operator, not * a word like should, you are free to structure the text however you wish. Here's an example: *

* *
 * import org.scalatest.freespec.AnyFreeSpec
 * 
 * class StackSpec extends AnyFreeSpec {
 *   "A Stack" - {
 *     "whenever it is empty" - {
 *       "certainly ought to" - {
 *         "be empty" in {
 *           // ...
 *         }
 *         "complain on peek" in {
 *           // ...
 *         }
 *         "complain on pop" in {
 *           // ...
 *         }
 *       }
 *     }
 *     "but when full, by contrast, must" - {
 *       "be full" in {
 *         // ...
 *       }
 *       "complain on push" in {
 *         // ...
 *       }
 *     }
 *   }
 * }
 * 
* *

* Running the above StackSpec in the interpreter would yield: *

* *
 * scala> org.scalatest.run(new StackSpec)
 * StackSpec:
 * A Stack 
 *   whenever it is empty 
 *     certainly ought to 
 *     - be empty
 *     - complain on peek
 *     - complain on pop
 *   but when full, by contrast, must 
 *   - be full
 *   - complain on push
 * 
* *

* A AnyFreeSpec can also be used to write a specification-style test in languages other than English. For * example: *

* *
 * import org.scalatest.freespec.AnyFreeSpec
 *
 * class ComputerRoomRulesSpec extends AnyFreeSpec {
 *   "Achtung!" - {
 *     "Alle touristen und non-technischen lookenpeepers!" - {
 *       "Das machine is nicht fuer fingerpoken und mittengrabben." in {
 *         // ...
 *       }
 *       "Is easy" - {
 *         "schnappen der springenwerk" in {
 *           // ...
 *         }
 *         "blowenfusen" in {
 *           // ...
 *         }
 *         "und poppencorken mit spitzen sparken." in {
 *           // ...
 *         }
 *       }
 *       "Das machine is diggen by experten only." in {
 *         // ...
 *       }
 *       "Is nicht fuer gerwerken by das dummkopfen." in {
 *         // ...
 *       }
 *       "Das rubbernecken sightseeren keepen das cottenpicken hands in das pockets." in {
 *         // ...
 *       }
 *       "Relaxen und watchen das blinkenlights." in {
 *         // ...
 *       }
 *     }
 *   }
 * }
 * 
* *

* Running the above ComputerRoomRulesSpec in the interpreter would yield: *

* *
 * scala> org.scalatest.run(new ComputerRoomRulesSpec)
 * ComputerRoomRulesSpec:
 * Achtung! 
 *   Alle touristen und non-technischen lookenpeepers! 
 *   - Das machine is nicht fuer fingerpoken und mittengrabben.
 *     Is easy 
 *     - schnappen der springenwerk
 *     - blowenfusen
 *     - und poppencorken mit spitzen sparken.
 *   - Das machine is diggen by experten only.
 *   - Is nicht fuer gerwerken by das dummkopfen.
 *   - Das rubbernecken sightseeren keepen das cottenpicken hands in das pockets.
 *   - Relaxen und watchen das blinkenlights.
 * 
* *

* A AnyFreeSpec'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 while the AnyFreeSpec is * in its registration phase. Any attempt to register a test after the AnyFreeSpec has * entered its ready phase, i.e., after run has been invoked on the AnyFreeSpec, * will be met with a thrown TestRegistrationClosedException. The recommended style * of using AnyFreeSpec 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, AnyFreeSpec adds a method * ignore to strings that can be used instead of in to register a test. For example, to temporarily * disable the test with the name "A Stack should pop values in last-in-first-out order", just * change “in” into “ignore,” like this: *

* *
 * package org.scalatest.examples.freespec.ignore
 * 
 * import org.scalatest.freespec.AnyFreeSpec
 * 
 * class SetSpec extends AnyFreeSpec {
 *   
 *   "A Set" - {
 *     "when empty" - {
 *       "should have size 0" ignore {
 *         assert(Set.empty.size === 0)
 *       }
 *       
 *       "should produce NoSuchElementException when head is invoked" in {
 *         assertThrows[NoSuchElementException] {
 *           Set.empty.head
 *         }
 *       }
 *     }
 *   }
 * }
 * 
* *

* If you run this version of SetSpec with: *

* *
 * scala> org.scalatest.run(new SetSpec)
 * 
* *

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

* *
 * A Set
 *   when empty
 *   - should have size 0 !!! IGNORED !!!
 *   - should produce NoSuchElementException when head is invoked
 * 
* *

* If you wish to temporarily ignore an entire suite of tests, you can (on the JVM, not Scala.js) annotate the test class with @Ignore, like this: *

* *
 * package org.scalatest.examples.freespec.ignoreall
 * 
 * import org.scalatest.freespec.AnyFreeSpec
 * import org.scalatest.Ignore
 *
 * @Ignore
 * class SetSpec extends AnyFreeSpec {
 *   
 *   "A Set" - {
 *     "when empty" - {
 *       "should have size 0" in {
 *         assert(Set.empty.size === 0)
 *       }
 *       
 *       "should produce NoSuchElementException when head is invoked" in {
 *         assertThrows[NoSuchElementException] {
 *           Set.empty.head
 *         }
 *       }
 *     }
 *   }
 * }
 * 
* *

* When you mark a test class with a tag annotation, ScalaTest will mark each test defined in that class with that tag. * Thus, marking the SetSpec in the above example with the @Ignore tag annotation means that both tests * in the class will be ignored. If you run the above SetSpec in the Scala interpreter, you'll see: *

* *
 * scala> org.scalatest.run(new SetSpec)
 * SetSpec:
 * A Set
 *   when empty
 *   - should have size 0 !!! IGNORED !!!
 *   - should produce NoSuchElementException when head is invoked !!! IGNORED !!!
 * 
* *

* Note that marking a test class as ignored won't prevent it from being discovered by ScalaTest. Ignored classes * will be discovered and run, and all their tests will be reported as ignored. This is intended to keep the ignored * class visible, to encourage the developers to eventually fix and “un-ignore” it. If you want to * prevent a class from being discovered at all (on the JVM, not Scala.js), use the DoNotDiscover annotation instead. *

* *

Informers

* *

* One of the parameters to AnyFreeSpec'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 AnyFreeSpec'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. *

* *

* One use case for the Informer is to pass more information about a specification to the reporter. For example, * the GivenWhenThen trait provides methods that use the implicit info provided by AnyFreeSpec * to pass such information to the reporter. Here's an example: *

* *
 * package org.scalatest.examples.freespec.info
 * 
 * import collection.mutable
 * import org.scalatest._
 * 
 * class SetSpec extends freespec.AnyFreeSpec with GivenWhenThen {
 *   
 *   "A mutable Set" - {
 *     "should allow an element to be added" in {
 *       Given("an empty mutable Set")
 *       val set = mutable.Set.empty[String]
 * 
 *       When("an element is added")
 *       set += "clarity"
 * 
 *       Then("the Set should have size 1")
 *       assert(set.size === 1)
 * 
 *       And("the Set should contain the added element")
 *       assert(set.contains("clarity"))
 * 
 *       info("That's all folks!")
 *     }
 *   }
 * }
 * 
* *

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

* *
 * scala> org.scalatest.run(new SetSpec)
 * A mutable Set
 * - should allow an element to be added
 *   + Given an empty mutable Set 
 *   + When an element is added 
 *   + Then the Set should have size 1 
 *   + And the Set should contain the added element 
 *   + That's all folks! 
 * 
* *

Documenters

* *

* AnyFreeSpec 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 AnyFreeSpec that uses markup: *

* *
 * package org.scalatest.examples.freespec.markup
 *
 * import collection.mutable
 * import org.scalatest._
 *
 * class SetSpec extends freespec.AnyFreeSpec 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.
 *
 *   """ }
 *
 *   "A mutable Set" - {
 *     "should allow an element to be added" in {
 *       Given("an empty mutable Set")
 *       val set = mutable.Set.empty[String]
 *
 *       When("an element is added")
 *       set += "clarity"
 *
 *       Then("the Set should have size 1")
 *       assert(set.size === 1)
 *
 *       And("the Set should contain the added element")
 *       assert(set.contains("clarity"))
 *
 *       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.freespec.note
 *
 * import collection.mutable
 * import org.scalatest._
 *
 * class SetSpec extends freespec.AnyFreeSpec {
 *
 *   "A mutable Set" - {
 *     "should allow an element to be added" in {
 *
 *       info("info is recorded")
 *       markup("markup is *also* recorded")
 *       note("notes are sent immediately")
 *       alert("alerts are also sent immediately")
 *
 *       val set = mutable.Set.empty[String]
 *       set += "clarity"
 *       assert(set.size === 1)
 *       assert(set.contains("clarity"))
 *     }
 *   }
 * }
 * 
* *
 * scala> org.scalatest.run(new SetSpec)
 * SetSpec:
 *  A mutable Set
 *    + notes are sent immediately
 *    + alerts are also sent immediately
 *  - should allow an element to be added
 *    + 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. *

* *

* 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. * You can mark tests as pending in a AnyFreeSpec like this: *

* *
 * package org.scalatest.examples.freespec.pending
 * 
 * import org.scalatest._
 * 
 * class SetSpec extends freespec.AnyFreeSpec {
 * 
 *   "A Set" - {
 *     "when empty" - {
 *       "should have size 0" in (pending)
 *       
 *       "should produce NoSuchElementException when head is invoked" in {
 *         assertThrows[NoSuchElementException] {
 *           Set.empty.head
 *         }
 *       }
 *     }
 *   }
 * }
 * 
* *

* If you run this version of SetSpec with: *

* *
 * scala> org.scalatest.run(new SetSpec)
 * 
* *

* It will run both tests but report that should have size 0 is pending. You'll see: *

* *
 * A Set
 *   when empty
 *   - should have size 0 (pending)
 *   - should produce NoSuchElementException when head is invoked
 * 
* *

* 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. For example, the following snippet in a AnyFreeSpec: *

* *
 *  "The Scala language" - {
 *     "should add correctly" in { 
 *       Given("two integers")
 *       When("they are added")
 *       Then("the result is the sum of the two numbers")
 *       pending
 *     }
 *     // ...
 * 
* *

* Would yield the following output when run in the interpreter: *

* *
 * The Scala language
 * - should add correctly (pending)
 *   + Given two integers 
 *   + When they are added 
 *   + Then the result is the sum of the two numbers 
 * 
* *

Tagging tests

* * A AnyFreeSpec's tests may be classified into groups by tagging them with string names. * As with any suite, when executing a AnyFreeSpec, groups of tests can * optionally be included and/or excluded. To tag a AnyFreeSpec'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 name, * com.mycompany.tags.DbTest, then you could * create a matching tag for AnyFreeSpecs like this: *

* *
 * import org.scalatest.Tag
 *
 * object DbTest extends Tag("com.mycompany.tags.DbTest")
 * 
* *

* Given these definitions, you could tag AnyFreeSpec tests like this: *

* *
 * package org.scalatest.examples.freespec.tagging
 * 
 * import org.scalatest.Tag
 * 
 * object DbTest extends Tag("com.mycompany.tags.DbTest")
 * 
 * import org.scalatest.freespec.AnyFreeSpec
 * import org.scalatest.tagobjects.Slow
 * 
 * class SetSpec extends AnyFreeSpec {
 * 
 *   "A Set" - {
 *     "when empty" - {
 *       "should have size 0" taggedAs(Slow) in {
 *         assert(Set.empty.size === 0)
 *       }
 *       
 *       "should produce NoSuchElementException when head is invoked" taggedAs(Slow, DbTest) in {
 *         assertThrows[NoSuchElementException] {
 *           Set.empty.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. *

* *

* It is recommended, though not required, that you create a corresponding tag annotation when you * create a Tag object. A tag annotation (on the JVM, not Scala.js) allows you to tag all the tests of a AnyFreeSpec in * one stroke by annotating the class. For more information and examples, see the * documentation for class Tag. On Scala.js, to tag all tests of a suite, you'll need to * tag each test individually at the test site. *

* * *

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 following sections * describe these techniques, including explaining the recommended usage * for each. But first, here's a table summarizing the options:

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* 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. *
* * *

Calling get-fixture methods

* *

* If you need to create the same mutable fixture objects in multiple tests, and don't need to clean them up after using them, the simplest approach is to write one or * more get-fixture methods. A get-fixture method returns a new instance of a needed fixture object (or an holder object containing * multiple fixture objects) each time it is called. You can call a get-fixture method at the beginning of each * test that needs the fixture, storing the returned object or objects in local variables. Here's an example: *

* *
 * package org.scalatest.examples.freespec.getfixture
 * 
 * import org.scalatest.freespec.AnyFreeSpec
 * import collection.mutable.ListBuffer
 * 
 * class ExampleSpec extends AnyFreeSpec {
 * 
 *   class Fixture {
 *     val builder = new StringBuilder("ScalaTest is ")
 *     val buffer = new ListBuffer[String]
 *   }
 *
 *   def fixture = new Fixture
 *   
 *   "Testing" - {
 *     "should be easy" in {
 *       val f = fixture
 *       f.builder.append("easy!")
 *       assert(f.builder.toString === "ScalaTest is easy!")
 *       assert(f.buffer.isEmpty)
 *       f.buffer += "sweet"
 *     }
 *   
 *     "should be fun" in {
 *       val f = fixture
 *       f.builder.append("fun!")
 *       assert(f.builder.toString === "ScalaTest is fun!")
 *       assert(f.buffer.isEmpty)
 *     }
 *   }
 * }
 * 
* *

* The “f.” in front of each use of a fixture object provides a visual indication of which objects * are part of the fixture, but if you prefer, you can import the the members with “import f._” and use the names directly. *

* *

* If you need to configure fixture objects differently in different tests, you can pass configuration into the get-fixture method. For example, if you could pass * in an initial value for a mutable fixture object as a parameter to the get-fixture method. *

* * *

Instantiating fixture-context objects

* *

* An alternate technique that is especially useful when different tests need different combinations of fixture objects is to define the fixture objects as instance variables * of fixture-context objects whose instantiation forms the body of tests. Like get-fixture methods, fixture-context objects are only * appropriate if you don't need to clean up the fixtures after using them. *

* * To use this technique, you define instance variables intialized with fixture objects in traits and/or classes, then in each test instantiate an object that * contains just the fixture objects needed by the test. Traits allow you to mix together just the fixture objects needed by each test, whereas classes * allow you to pass data in via a constructor to configure the fixture objects. Here's an example in which fixture objects are partitioned into two traits * and each test just mixes together the traits it needs: *

* *
 * package org.scalatest.examples.freespec.fixturecontext
 * 
 * import collection.mutable.ListBuffer
 * import org.scalatest.freespec.AnyFreeSpec
 * 
 * class ExampleSpec extends AnyFreeSpec {
 * 
 *   trait Builder {
 *     val builder = new StringBuilder("ScalaTest is ")
 *   }
 * 
 *   trait Buffer {
 *     val buffer = ListBuffer("ScalaTest", "is")
 *   }
 * 
 *   "Testing" - {
 *     // This test needs the StringBuilder fixture
 *     "should be productive" in new Builder {
 *       builder.append("productive!")
 *       assert(builder.toString === "ScalaTest is productive!")
 *     }
 *   }
 * 
 *   "Test code" - {
 *     // This test needs the ListBuffer[String] fixture
 *     "should be readable" in new Buffer {
 *       buffer += ("readable!")
 *       assert(buffer === List("ScalaTest", "is", "readable!"))
 *     }
 * 
 *     // This test needs both the StringBuilder and ListBuffer
 *     "should be clear and concise" in new Builder with Buffer {
 *       builder.append("clear!")
 *       buffer += ("concise!")
 *       assert(builder.toString === "ScalaTest is clear!")
 *       assert(buffer === List("ScalaTest", "is", "concise!"))
 *     }
 *   }
 * }
 * 
* * *

Overriding withFixture(NoArgTest)

* *

* Although the get-fixture method and fixture-context object approaches take care of setting up a fixture at the beginning of each * test, they don't address the problem of cleaning up a fixture at the end of the test. If you just need to perform a side-effect at the beginning or end of * a test, and don't need to actually pass any fixture objects into the test, you can override withFixture(NoArgTest), one of ScalaTest's * lifecycle methods defined in trait Suite. *

* *

* Trait Suite's implementation of runTest passes a no-arg test function to withFixture(NoArgTest). It is withFixture's * responsibility to invoke that test function. Suite's implementation of withFixture simply * invokes the function, like this: *

* *
 * // Default implementation in trait Suite
 * protected def withFixture(test: NoArgTest) = {
 *   test()
 * }
 * 
* *

* You can, therefore, override withFixture to perform setup before and/or cleanup after invoking the test function. If * you have cleanup to perform, you should invoke the test function inside a try block and perform the cleanup in * a finally clause, in case an exception propagates back through withFixture. (If a test fails because of an exception, * the test function invoked by withFixture will result in a [[org.scalatest.Failed Failed]] wrapping the exception. Nevertheless, * best practice is to perform cleanup in a finally clause just in case an exception occurs.) *

* *

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

* *
 * // Your implementation
 * override def withFixture(test: NoArgTest) = {
 *   // Perform setup
 *   try super.withFixture(test) // Invoke the test function
 *   finally {
 *     // Perform cleanup
 *   }
 * }
 * 
* *

* Here's an example in which withFixture(NoArgTest) is used to take a snapshot of the working directory if a test fails, and * send that information to the reporter: *

* *
 * package org.scalatest.examples.freespec.noargtest
 * 
 * import java.io.File
 * import org.scalatest._
 * 
 * class ExampleSpec extends freespec.AnyFreeSpec {
 * 
 *   override def withFixture(test: NoArgTest) = {
 * 
 *     super.withFixture(test) match {
 *       case failed: Failed =>
 *         val currDir = new File(".")
 *         val fileNames = currDir.list()
 *         info("Dir snapshot: " + fileNames.mkString(", "))
 *         failed
 *       case other => other
 *     }
 *   }
 * 
 *   "This test" - {
 *     "should succeed" in {
 *       assert(1 + 1 === 2)
 *     }
 * 
 *     "should fail" in {
 *       assert(1 + 1 === 3)
 *     }
 *   }
 * }
 * 
* *

* Running this version of ExampleSuite in the interpreter in a directory with two files, hello.txt and world.txt * would give the following output: *

* *
 * scala> org.scalatest.run(new ExampleSuite)
 * ExampleSuite:
 * This test
 * - should succeed
 * - should fail *** FAILED ***
 *   2 did not equal 3 (:33)
 *   + Dir snapshot: hello.txt, world.txt 
 * 
* *

* Note that the NoArgTest passed to withFixture, in addition to * an apply method that executes the test, also includes the test name and the config * map passed to runTest. Thus you can also use the test name and configuration objects in your withFixture * implementation. *

* * *

Calling loan-fixture methods

* *

* If you need to both pass a fixture object into a test and perform cleanup at the end of the test, you'll need to use the loan pattern. * If different tests need different fixtures that require cleanup, you can implement the loan pattern directly by writing loan-fixture methods. * A loan-fixture method takes a function whose body forms part or all of a test's code. It creates a fixture, passes it to the test code by invoking the * function, then cleans up the fixture after the function returns. *

* *

* The following example shows three tests that use two fixtures, a database and a file. Both require cleanup after, so each is provided via a * loan-fixture method. (In this example, the database is simulated with a StringBuffer.) *

* *
 * package org.scalatest.examples.freespec.loanfixture
 * 
 * import java.util.concurrent.ConcurrentHashMap
 * 
 * object DbServer { // Simulating a database server
 *   type Db = StringBuffer
 *   private val databases = new ConcurrentHashMap[String, Db]
 *   def createDb(name: String): Db = {
 *     val db = new StringBuffer
 *     databases.put(name, db)
 *     db
 *   }
 *   def removeDb(name: String) {
 *     databases.remove(name)
 *   }
 * }
 * 
 * import org.scalatest.freespec.AnyFreeSpec
 * import DbServer._
 * import java.util.UUID.randomUUID
 * import java.io._
 * 
 * class ExampleSpec extends AnyFreeSpec {
 * 
 *   def withDatabase(testCode: Db => Any) {
 *     val dbName = randomUUID.toString
 *     val db = createDb(dbName) // create the fixture
 *     try {
 *       db.append("ScalaTest is ") // perform setup
 *       testCode(db) // "loan" the fixture to the test
 *     }
 *     finally removeDb(dbName) // clean up the fixture
 *   }
 * 
 *   def withFile(testCode: (File, FileWriter) => Any) {
 *     val file = File.createTempFile("hello", "world") // create the fixture
 *     val writer = new FileWriter(file)
 *     try {
 *       writer.write("ScalaTest is ") // set up the fixture
 *       testCode(file, writer) // "loan" the fixture to the test
 *     }
 *     finally writer.close() // clean up the fixture
 *   }
 * 
 *   "Testing" - {
 *     // This test needs the file fixture
 *     "should be productive" in withFile { (file, writer) =>
 *       writer.write("productive!")
 *       writer.flush()
 *       assert(file.length === 24)
 *     }
 *   }
 *   
 *   "Test code" - {
 *     // This test needs the database fixture
 *     "should be readable" in withDatabase { db =>
 *       db.append("readable!")
 *       assert(db.toString === "ScalaTest is readable!")
 *     }
 * 
 *     // This test needs both the file and the database
 *     "should be clear and concise" in withDatabase { db =>
 *       withFile { (file, writer) => // loan-fixture methods compose
 *         db.append("clear!")
 *         writer.write("concise!")
 *         writer.flush()
 *         assert(db.toString === "ScalaTest is clear!")
 *         assert(file.length === 21)
 *       }
 *     }
 *   }
 * }
 * 
* *

* As demonstrated by the last test, loan-fixture methods compose. Not only do loan-fixture methods allow you to * give each test the fixture it needs, they allow you to give a test multiple fixtures and clean everything up afterwards. *

* *

* Also demonstrated in this example is the technique of giving each test its own "fixture sandbox" to play in. When your fixtures * involve external side-effects, like creating files or databases, it is a good idea to give each file or database a unique name as is * done in this example. This keeps tests completely isolated, allowing you to run them in parallel if desired. *

* * *

Overriding withFixture(OneArgTest)

* *

* If all or most tests need the same fixture, you can avoid some of the boilerplate of the loan-fixture method approach by using a FixtureAnyFreeSpec * and overriding withFixture(OneArgTest). * Each test in a FixtureAnyFreeSpec takes a fixture as a parameter, allowing you to pass the fixture into * the test. You must indicate the type of the fixture parameter by specifying FixtureParam, and implement a * withFixture method that takes a OneArgTest. This withFixture method is responsible for * invoking the one-arg test function, so you can perform fixture set up before, and clean up after, invoking and passing * the fixture into the test function. *

* *

* To enable the stacking of traits that define withFixture(NoArgTest), it is a good idea to let * withFixture(NoArgTest) invoke the test function instead of invoking the test * function directly. To do so, you'll need to convert the OneArgTest to a NoArgTest. You can do that by passing * the fixture object to the toNoArgTest method of OneArgTest. In other words, instead of * writing “test(theFixture)”, you'd delegate responsibility for * invoking the test function to the withFixture(NoArgTest) method of the same instance by writing: *

* *
 * withFixture(test.toNoArgTest(theFixture))
 * 
* *

* Here's a complete example: *

* *
 * package org.scalatest.examples.freespec.oneargtest
 * 
 * import org.scalatest._
 * import java.io._
 * 
 * class ExampleSpec extends freespec.FixtureAnyFreeSpec {
 * 
 *   case class FixtureParam(file: File, writer: FileWriter)
 * 
 *   def withFixture(test: OneArgTest) = {
 *
 *     // create the fixture
 *     val file = File.createTempFile("hello", "world")
 *     val writer = new FileWriter(file)
 *     val theFixture = FixtureParam(file, writer)
 *
 *     try {
 *       writer.write("ScalaTest is ") // set up the fixture
 *       withFixture(test.toNoArgTest(theFixture)) // "loan" the fixture to the test
 *     }
 *     finally writer.close() // clean up the fixture
 *   }
 *
 *   "Testing" - {
 *     "should be easy" in { f =>
 *       f.writer.write("easy!")
 *       f.writer.flush()
 *       assert(f.file.length === 18)
 *     }
 * 
 *     "should be fun" in { f =>
 *       f.writer.write("fun!")
 *       f.writer.flush()
 *       assert(f.file.length === 17)
 *     }
 *   } 
 * }
 * 
* *

* In this example, the tests actually required two fixture objects, a File and a FileWriter. In such situations you can * simply define the FixtureParam type to be a tuple containing the objects, or as is done in this example, a case class containing * the objects. For more information on the withFixture(OneArgTest) technique, see the documentation for FixtureAnyFreeSpec. *

* * *

Mixing in BeforeAndAfter

* *

* In all the shared fixture examples shown so far, the activities of creating, setting up, and cleaning up the fixture objects have been * performed during the test. This means that if an exception occurs during any of these activities, it will be reported as a test failure. * Sometimes, however, you may want setup to happen before the test starts, and cleanup after the test has completed, so that if an * exception occurs during setup or cleanup, the entire suite aborts and no more tests are attempted. The simplest way to accomplish this in ScalaTest is * to mix in trait BeforeAndAfter. With this trait you can denote a bit of code to run before each test * with before and/or after each test each test with after, like this: *

* *
 * package org.scalatest.examples.freespec.beforeandafter
 * 
 * import org.scalatest.freespec.AnyFreeSpec
 * import org.scalatest.BeforeAndAfter
 * import collection.mutable.ListBuffer
 * 
 * class ExampleSpec extends AnyFreeSpec with BeforeAndAfter {
 * 
 *   val builder = new StringBuilder
 *   val buffer = new ListBuffer[String]
 * 
 *   before {
 *     builder.append("ScalaTest is ")
 *   }
 * 
 *   after {
 *     builder.clear()
 *     buffer.clear()
 *   }
 * 
 *   "Testing" - {
 *     "should be easy" in {
 *       builder.append("easy!")
 *       assert(builder.toString === "ScalaTest is easy!")
 *       assert(buffer.isEmpty)
 *       buffer += "sweet"
 *     }
 * 
 *     "should be fun" in {
 *       builder.append("fun!")
 *       assert(builder.toString === "ScalaTest is fun!")
 *       assert(buffer.isEmpty)
 *     }
 *   }
 * }
 * 
* *

* Note that the only way before and after code can communicate with test code is via some side-effecting mechanism, commonly by * reassigning instance vars or by changing the state of mutable objects held from instance vals (as in this example). If using * instance vars or mutable objects held from instance vals you wouldn't be able to run tests in parallel in the same instance * of the test class (on the JVM, not Scala.js) unless you synchronized access to the shared, mutable state. This is why ScalaTest's ParallelTestExecution trait extends * OneInstancePerTest. By running each test in its own instance of the class, each test has its own copy of the instance variables, so you * don't need to synchronize. If you mixed ParallelTestExecution into the ExampleSuite above, the tests would run in parallel just fine * without any synchronization needed on the mutable StringBuilder and ListBuffer[String] objects. *

* *

* Although BeforeAndAfter provides a minimal-boilerplate way to execute code before and after tests, it isn't designed to enable stackable * traits, because the order of execution would be non-obvious. If you want to factor out before and after code that is common to multiple test suites, you * should use trait BeforeAndAfterEach instead, as shown later in the next section, * composing fixtures by stacking traits. *

* *

Composing fixtures by stacking traits

* *

* In larger projects, teams often end up with several different fixtures that test classes need in different combinations, * and possibly initialized (and cleaned up) in different orders. A good way to accomplish this in ScalaTest is to factor the individual * fixtures into traits that can be composed using the stackable trait pattern. This can be done, for example, by placing * withFixture methods in several traits, each of which call super.withFixture. Here's an example in * which the StringBuilder and ListBuffer[String] fixtures used in the previous examples have been * factored out into two stackable fixture traits named Builder and Buffer: *

* *
 * package org.scalatest.examples.freespec.composingwithfixture
 * 
 * import org.scalatest._
 * import collection.mutable.ListBuffer
 * 
 * trait Builder extends TestSuiteMixin { this: TestSuite =>
 * 
 *   val builder = new StringBuilder
 * 
 *   abstract override def withFixture(test: NoArgTest) = {
 *     builder.append("ScalaTest is ")
 *     try super.withFixture(test) // To be stackable, must call super.withFixture
 *     finally builder.clear()
 *   }
 * }
 * 
 * trait Buffer extends TestSuiteMixin { this: TestSuite =>
 * 
 *   val buffer = new ListBuffer[String]
 * 
 *   abstract override def withFixture(test: NoArgTest) = {
 *     try super.withFixture(test) // To be stackable, must call super.withFixture
 *     finally buffer.clear()
 *   }
 * }
 * 
 * class ExampleSpec extends freespec.AnyFreeSpec with Builder with Buffer {
 * 
 *   "Testing" - {
 *     "should be easy" in {
 *       builder.append("easy!")
 *       assert(builder.toString === "ScalaTest is easy!")
 *       assert(buffer.isEmpty)
 *       buffer += "sweet"
 *     }
 * 
 *     "should be fun" in {
 *       builder.append("fun!")
 *       assert(builder.toString === "ScalaTest is fun!")
 *       assert(buffer.isEmpty)
 *       buffer += "clear"
 *     }
 *   }
 * }
 * 
* *

* By mixing in both the Builder and Buffer traits, ExampleSuite gets both fixtures, which will be * initialized before each test and cleaned up after. The order the traits are mixed together determines the order of execution. * In this case, Builder is “super” to Buffer. If you wanted Buffer to be “super” * to Builder, you need only switch the order you mix them together, like this: *

* *
 * class Example2Spec extends freespec.AnyFreeSpec with Buffer with Builder
 * 
* *

* And if you only need one fixture you mix in only that trait: *

* *
 * class Example3Spec extends freespec.AnyFreeSpec with Builder
 * 
* *

* Another way to create stackable fixture traits is by extending the BeforeAndAfterEach * and/or BeforeAndAfterAll traits. * BeforeAndAfterEach has a beforeEach method that will be run before each test (like JUnit's setUp), * and an afterEach method that will be run after (like JUnit's tearDown). * Similarly, BeforeAndAfterAll has a beforeAll method that will be run before all tests, * and an afterAll method that will be run after all tests. Here's what the previously shown example would look like if it * were rewritten to use the BeforeAndAfterEach methods instead of withFixture: *

* *
 * package org.scalatest.examples.freespec.composingbeforeandaftereach
 * 
 * import org.scalatest._
 * import org.scalatest.BeforeAndAfterEach
 * import collection.mutable.ListBuffer
 * 
 * trait Builder extends BeforeAndAfterEach { this: Suite =>
 * 
 *   val builder = new StringBuilder
 * 
 *   override def beforeEach() {
 *     builder.append("ScalaTest is ")
 *     super.beforeEach() // To be stackable, must call super.beforeEach
 *   }
 * 
 *   override def afterEach() {
 *     try super.afterEach() // To be stackable, must call super.afterEach
 *     finally builder.clear()
 *   }
 * }
 * 
 * trait Buffer extends BeforeAndAfterEach { this: Suite =>
 * 
 *   val buffer = new ListBuffer[String]
 * 
 *   override def afterEach() {
 *     try super.afterEach() // To be stackable, must call super.afterEach
 *     finally buffer.clear()
 *   }
 * }
 * 
 * class ExampleSpec extends freespec.AnyFreeSpec with Builder with Buffer {
 * 
 *   "Testing" - {
 *     "should be easy" in {
 *       builder.append("easy!")
 *       assert(builder.toString === "ScalaTest is easy!")
 *       assert(buffer.isEmpty)
 *       buffer += "sweet"
 *     }
 * 
 *     "should be fun" in {
 *       builder.append("fun!")
 *       assert(builder.toString === "ScalaTest is fun!")
 *       assert(buffer.isEmpty)
 *       buffer += "clear"
 *     }
 *   }
 * }
 * 
* *

* To get the same ordering as withFixture, place your super.beforeEach call at the end of each * beforeEach method, and the super.afterEach call at the beginning of each afterEach * method, as shown in the previous example. It is a good idea to invoke super.afterEach in a try * block and perform cleanup in a finally clause, as shown in the previous example, because this ensures the * cleanup code is performed even if super.afterEach throws an exception. *

* *

* The difference between stacking traits that extend BeforeAndAfterEach versus traits that implement withFixture is * that setup and cleanup code happens before and after the test in BeforeAndAfterEach, but at the beginning and * end of the test in withFixture. Thus if a withFixture method completes abruptly with an exception, it is * considered a failed test. By contrast, if any of the beforeEach or afterEach methods of BeforeAndAfterEach * complete abruptly, it is considered an aborted suite, which will result in a SuiteAborted event. *

* *

Shared tests

* *

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

* *
 * import scala.collection.mutable.ListBuffer
 * 
 * class Stack[T] {
 *
 *   val MAX = 10
 *   private val buf = new ListBuffer[T]
 *
 *   def push(o: T) {
 *     if (!full)
 *       buf.prepend(o)
 *     else
 *       throw new IllegalStateException("can't push onto a full stack")
 *   }
 *
 *   def pop(): T = {
 *     if (!empty)
 *       buf.remove(0)
 *     else
 *       throw new IllegalStateException("can't pop an empty stack")
 *   }
 *
 *   def peek: T = {
 *     if (!empty)
 *       buf(0)
 *     else
 *       throw new IllegalStateException("can't pop an empty stack")
 *   }
 *
 *   def full: Boolean = buf.size == MAX
 *   def empty: Boolean = buf.size == 0
 *   def size = buf.size
 *
 *   override def toString = buf.mkString("Stack(", ", ", ")")
 * }
 * 
* *

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

* *

* For example, here the nonEmptyStack behavior function (in this case, a behavior method) is * defined in a trait along with another method containing shared tests for non-full stacks: *

* *
 * trait StackBehaviors { this: AnyFreeSpec =>
 * 
 *   def nonEmptyStack(newStack: => Stack[Int], lastItemAdded: Int) {
 *
 *     "be non-empty" in {
 *       assert(!newStack.empty)
 *     }
 *
 *     "return the top item on peek" in {
 *       assert(newStack.peek === lastItemAdded)
 *     }
 *
 *     "not remove the top item on peek" in {
 *       val stack = newStack
 *       val size = stack.size
 *       assert(stack.peek === lastItemAdded)
 *       assert(stack.size === size)
 *     }
 *
 *     "remove the top item on pop" in {
 *       val stack = newStack
 *       val size = stack.size
 *       assert(stack.pop === lastItemAdded)
 *       assert(stack.size === size - 1)
 *     }
 *   }
 *
 *   def nonFullStack(newStack: => Stack[Int]) {
 *
 *     "not be full" in {
 *       assert(!newStack.full)
 *     }
 *
 *     "add to the top on push" in {
 *       val stack = newStack
 *       val size = stack.size
 *       stack.push(7)
 *       assert(stack.size === size + 1)
 *       assert(stack.peek === 7)
 *     }
 *   }
 * }
 * 
* *

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

* *
 * behave like nonEmptyStack(stackWithOneItem, lastValuePushed)
 * behave like nonFullStack(stackWithOneItem)
 * 
* *

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

* *
 * behave like nonEmptyStack // assuming lastValuePushed is also in scope inside nonEmptyStack
 * behave like nonFullStack
 * 
* *

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

* *
 * class SharedTestExampleSpec extends AnyFreeSpec with StackBehaviors {
 * 
 *   // Stack fixture creation methods
 *   def emptyStack = new Stack[Int]
 * 
 *   def fullStack = {
 *     val stack = new Stack[Int]
 *     for (i <- 0 until stack.MAX)
 *       stack.push(i)
 *     stack
 *   }
 * 
 *   def stackWithOneItem = {
 *     val stack = new Stack[Int]
 *     stack.push(9)
 *     stack
 *   }
 * 
 *   def stackWithOneItemLessThanCapacity = {
 *     val stack = new Stack[Int]
 *     for (i <- 1 to 9)
 *       stack.push(i)
 *     stack
 *   }
 * 
 *   val lastValuePushed = 9
 * 
 *   "A Stack" - {
 *     "when empty" - {
 *       "should be empty" in {
 *         assert(emptyStack.empty)
 *       }
 * 
 *       "should complain on peek" in {
 *         assertThrows[IllegalStateException] {
 *           emptyStack.peek
 *         }
 *       }
 *
 *       "should complain on pop" in {
 *         assertThrows[IllegalStateException] {
 *           emptyStack.pop
 *         }
 *       }
 *     }
 * 
 *     "when it contains one item" - {
 *       "should" - {
 *         behave like nonEmptyStack(stackWithOneItem, lastValuePushed)
 *         behave like nonFullStack(stackWithOneItem)
 *       }
 *     }
 *     
 *     "when it contains one item less than capacity" - {
 *       "should" - {
 *         behave like nonEmptyStack(stackWithOneItemLessThanCapacity, lastValuePushed)
 *         behave like nonFullStack(stackWithOneItemLessThanCapacity)
 *       }
 *     }
 * 
 *     "when full" - {
 *       "should be full" in {
 *         assert(fullStack.full)
 *       }
 * 
 *       "should" - {
 *         behave like nonEmptyStack(fullStack, lastValuePushed)
 *       }
 * 
 *       "should complain on a push" in {
 *         assertThrows[IllegalStateException] {
 *           fullStack.push(10)
 *         }
 *       }
 *     }
 *   }
 * }
 * 
* *

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

* *
 * scala> org.scalatest.run(new SharedTestExampleSpec)
 * SharedTestExampleSpec:
 * A Stack 
 *   when empty 
 *   - should be empty
 *   - should complain on peek
 *   - should complain on pop
 *   when it contains one item 
 *     should 
 *     - be non-empty
 *     - return the top item on peek
 *     - not remove the top item on peek
 *     - remove the top item on pop
 *     - not be full
 *     - add to the top on push
 *   when it contains one item less than capacity 
 *     should 
 *     - be non-empty
 *     - return the top item on peek
 *     - not remove the top item on peek
 *     - remove the top item on pop
 *     - not be full
 *     - add to the top on push
 *   when full 
 *   - should be full
 *     should 
 *     - be non-empty
 *     - return the top item on peek
 *     - not remove the top item on peek
 *     - remove the top item on pop
 *   - should complain on a push
 * 
* *

* One thing to keep in mind when using shared tests is that in ScalaTest, each test in a suite must have a unique name. * If you register the same tests repeatedly in the same suite, one problem you may encounter is an exception at runtime * complaining that multiple tests are being registered with the same test name. A good way to solve this problem in a AnyFreeSpec is to make sure * each test is in the context of different surrounding description clauses, * because a test's name is the concatenation of its surrounding clauses, followed by the test's text. * For example, the following code in a AnyFreeSpec would register a test with the name "A Stack when empty should be empty": *

* *
 * "A Stack" - {
 *   "when empty" - {
 *     "should be empty" in {
 *       assert(emptyStack.empty)
 *     }
 *   }
 * }
 * // ...
 * 
* *

* If the "should be empty" test was factored out into a behavior function, it could be called repeatedly so long * as each invocation of the behavior function is in the context of a different surrounding description (dash) clauses. *

* * @author Bill Venners */ @Finders(Array("org.scalatest.finders.FreeSpecFinder")) class AnyFreeSpec extends AnyFreeSpecLike { /** * 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. * * @return a user-friendly string for this suite */ override def toString: String = Suite.suiteToString(None, this) }




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