org.scalatest.fixture.PropSpec.scala Maven / Gradle / Ivy
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/*
* Copyright 2001-2009 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.fixture
import org.scalatest._
import scala.collection.immutable.ListSet
import org.scalatest.Suite.autoTagClassAnnotations
/**
* A sister trait to org.scalatest.PropSpec that can pass a fixture object into its tests.
*
*
* Recommended Usage:
* Use trait fixture.PropSpec in situations for which PropSpec
* would be a good choice, when all or most tests need the same fixture objects
* that must be cleaned up afterwords. Note: fixture.PropSpec is intended for use in special
* situations, with trait PropSpec used for general needs. For
* more insight into where fixture.PropSpec fits in the big picture, see
* the withFixture(OneArgTest) subsection of
* the Shared fixtures section in the documentation for trait PropSpec.
*
*
*
* Trait fixture.PropSpec behaves similarly to trait org.scalatest.PropSpec, except that tests may have a
* fixture parameter. The type of the
* fixture parameter is defined by the abstract FixtureParam type, which is declared as a member of this trait.
* This trait also declares an abstract withFixture method. This withFixture method
* takes a OneArgTest, which is a nested trait defined as a member of this trait.
* OneArgTest has an apply method that takes a FixtureParam.
* This apply method is responsible for running a test.
* This trait's runTest method delegates the actual running of each test to withFixture, passing
* in the test code to run via the OneArgTest argument. The withFixture method (abstract in this trait) is responsible
* for creating the fixture argument and passing it to the test function.
*
*
*
* Subclasses of this trait must, therefore, do three things differently from a plain old org.scalatest.PropSpec:
*
*
*
* - define the type of the fixture parameter by specifying type
FixtureParam
* - define the
withFixture(OneArgTest) method
* - write tests that take a fixture parameter
* - (You can also define tests that don't take a fixture parameter.)
*
*
*
* Here's an example:
*
*
*
* package org.scalatest.examples.fixture.propspec
*
* import org.scalatest._
* import prop.PropertyChecks
* import java.io._
*
* class ExampleSpec extends fixture.PropSpec with PropertyChecks with ShouldMatchers {
*
* // 1. define type FixtureParam
* type FixtureParam = FileReader
*
* // 2. define the withFixture method
* def withFixture(test: OneArgTest) {
*
* val FileName = "TempFile.txt"
*
* // Set up the temp file needed by the test
* val writer = new FileWriter(FileName)
* try {
* writer.write("Hello, test!")
* }
* finally {
* writer.close()
* }
*
* // Create the reader needed by the test
* val reader = new FileReader(FileName)
*
* try {
* // Run the test using the temp file
* test(reader)
* }
* finally {
* // Close and delete the temp file
* reader.close()
* val file = new File(FileName)
* file.delete()
* }
* }
*
* // 3. write property-based tests that take a fixture parameter
* // (Hopefully less contrived than the examples shown here.)
* property("can read from a temp file") { reader =>
* var builder = new StringBuilder
* var c = reader.read()
* while (c != -1) {
* builder.append(c.toChar)
* c = reader.read()
* }
* val fileContents = builder.toString
* forAll { (c: Char) =>
* whenever (c != 'H') {
* fileContents should not startWith c.toString
* }
* }
* }
*
* property("can read the first char of the temp file") { reader =>
* val firstChar = reader.read()
* forAll { (c: Char) =>
* whenever (c != 'H') {
* c should not equal firstChar
* }
* }
* }
*
* // (You can also write tests that don't take a fixture parameter.)
* property("can write tests that don't take the fixture") { () =>
* forAll { (i: Int) => i + i should equal (2 * i) }
* }
* }
*
*
*
* Note: to run the examples on this page, you'll need to include ScalaCheck on the classpath in addition to ScalaTest.
*
*
*
* In the previous example, withFixture creates and initializes a temp file, then invokes the test function,
* passing in a FileReader connected to that file. In addition to setting up the fixture before a test,
* the withFixture method also cleans it up afterwards. If you need to do some clean up
* that must happen even if a test fails, you should invoke the test function from inside a try block and do
* the cleanup in a finally clause, as shown in the previous example.
*
*
*
* The reason you must perform cleanup in a finally clause is that withFixture is called by
* runTest, which expects an exception to be thrown to indicate a failed test. Thus when you invoke
* the test function, it may complete abruptly with an exception. The finally clause will
* ensure the fixture cleanup happens as that exception propagates back up the call stack to runTest.
*
*
*
* If a test doesn't need the fixture, you can indicate that by providing a no-arg instead of a one-arg function.
* In other words, instead of starting your function literal
* with something like “reader =>”, you'd start it with “() =>”, as is done
* in the third test in the above example. For such tests, runTest
* will not invoke withFixture(OneArgTest). It will instead directly invoke withFixture(NoArgTest).
*
*
*
* Passing multiple fixture objects
*
*
* If the fixture you want to pass into your tests consists of multiple objects, you will need to combine
* them into one object to use this trait. One good approach to passing multiple fixture objects is
* to encapsulate them in a case class. Here's an example:
*
*
*
* case class F(builder: StringBuilder, buffer: ListBuffer[String])
* type FixtureParam = F
*
*
*
* 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.fixture.propspec.multi
*
* import org.scalatest._
* import prop.PropertyChecks
* import scala.collection.mutable.ListBuffer
*
* class ExampleSpec extends fixture.PropSpec with PropertyChecks with ShouldMatchers {
*
* case class F(builder: StringBuilder, buffer: ListBuffer[String])
* type FixtureParam = F
*
* def withFixture(test: OneArgTest) {
*
* // Create needed mutable objects
* val stringBuilder = new StringBuilder("ScalaTest is ")
* val listBuffer = new ListBuffer[String]
* val theFixture = F(stringBuilder, listBuffer)
*
* // Invoke the test function, passing in the mutable objects
* withFixture(test.toNoArgTest(theFixture))
* }
*
* property("testing should be easy") { f =>
* f.builder.append("easy!")
* assert(f.builder.toString === "ScalaTest is easy!")
* assert(f.buffer.isEmpty)
* val firstChar = f.builder(0)
* forAll { (c: Char) =>
* whenever (c != 'S') {
* c should not equal firstChar
* }
* }
* f.buffer += "sweet"
* }
*
* property("testing should be fun") { f =>
* f.builder.append("fun!")
* assert(f.builder.toString === "ScalaTest is fun!")
* assert(f.buffer.isEmpty)
* val firstChar = f.builder(0)
* forAll { (c: Char) =>
* whenever (c != 'S') {
* c should not equal firstChar
* }
* }
* }
* }
*
*
* @author Bill Venners
*/
@Finders(Array("org.scalatest.finders.PropSpecFinder"))
trait PropSpec extends Suite { thisSuite =>
private final val engine = new FixtureEngine[FixtureParam]("concurrentFixturePropSpecMod", "FixturePropSpec")
import engine._
private[scalatest] val sourceFileName = "PropSpec.scala"
/**
* Returns an Informer 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
* fixture.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
* throw an exception. This method can be called safely by any thread.
*/
implicit protected def info: Informer = atomicInformer.get
/**
* 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.
*
* @param testName the name of the test
* @param testTags the optional list of tags for this test
* @param testFun the test function
* @throws TestRegistrationClosedException if invoked after run has been invoked on this suite
* @throws DuplicateTestNameException if a test with the same name has been registered previously
* @throws NotAllowedException if testName had been registered previously
* @throws NullPointerException if testName or any passed test tag is null
*/
protected def property(testName: String, testTags: Tag*)(testFun: FixtureParam => Any) {
registerTest(testName, testFun, "testCannotAppearInsideAnotherTest", sourceFileName, "property", 4, -2, None, None, None, testTags: _*)
}
/**
* 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.
*
* @param testName the name of the test
* @param testTags the optional list of tags for this test
* @param testFun the test function
* @throws TestRegistrationClosedException if invoked after run has been invoked on this suite
* @throws DuplicateTestNameException if a test with the same name has been registered previously
* @throws NotAllowedException if testName had been registered previously
*/
protected def ignore(testName: String, testTags: Tag*)(testFun: FixtureParam => Any) {
registerIgnoredTest(testName, testFun, "ignoreCannotAppearInsideATest", sourceFileName, "ignore", 4, 2, None, testTags: _*)
}
/**
* An immutable Set of test names. If this fixture.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.
*
*/
override def testNames: Set[String] = {
// I'm returning a ListSet here so that they tests will be run in registration order
ListSet(atomic.get.testNamesList.toArray: _*)
}
/**
* Run a test. This trait's implementation runs the test registered with the name specified by testName.
*
* @param testName the name of one test to run.
* @param reporter the Reporter to which results will be reported
* @param stopper the Stopper that will be consulted to determine whether to stop execution early.
* @param configMap a Map of properties that can be used by the executing Suite of tests.
* @throws IllegalArgumentException if testName is defined but a test with that name does not exist on this fixture.PropSpec
* @throws NullPointerException if any of testName, reporter, stopper, or configMap
* is null.
*/
protected override def runTest(testName: String, args: Args): Status = {
def invokeWithFixture(theTest: TestLeaf) {
theTest.testFun match {
case wrapper: NoArgTestWrapper[_] =>
withFixture(new FixturelessTestFunAndConfigMap(testName, wrapper.test, args.configMap))
case fun => withFixture(new TestFunAndConfigMap(testName, fun, args.configMap))
}
}
runTestImpl(thisSuite, testName, args, true, invokeWithFixture)
}
/**
* A Map whose keys are String tag names to which tests in this fixture.PropSpec belong, and values
* the Set of test names that belong to each tag. If this fixture.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 test and ignore.
*
*
*
* In addition, this trait's implementation will also auto-tag tests with class level annotations.
* For example, if you annotate @Ignore at the class level, all test methods in the class will be auto-annotated with @Ignore.
*
*/
override def tags: Map[String, Set[String]] = autoTagClassAnnotations(atomic.get.tagsMap, this)
protected override def runTests(testName: Option[String], args: Args): Status = {
runTestsImpl(thisSuite, testName, args, info, true, runTest)
}
override def run(testName: Option[String], args: Args): Status = {
runImpl(thisSuite, testName, args, super.run)
}
/**
* Registers shared tests.
*
*
* This method enables the following syntax for shared tests in a fixture.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
* trait PropSpec.
*
*/
protected def propertiesFor(unit: Unit) {}
@deprecated("Use propertiesFor instead.")
protected def testsFor(unit: Unit) {}
/**
* Implicitly converts a function that takes no parameters and results in PendingNothing to
* a function from FixtureParam to Any, to enable pending tests to registered as by-name parameters
* by methods that require a test function that takes a FixtureParam.
*
*
* This method makes it possible to write pending tests as simply (pending), without needing
* to write (fixture => pending).
*
*/
protected implicit def convertPendingToFixtureFunction(f: => PendingNothing): (FixtureParam => Any) = {
fixture => f
}
/**
* Implicitly converts a function that takes no parameters and results in Any to
* a function from FixtureParam to Any, to enable no-arg tests to registered
* by methods that require a test function that takes a FixtureParam.
*/
protected implicit def convertNoArgToFixtureFunction(fun: () => Any): (FixtureParam => Any) =
new NoArgTestWrapper(fun)
/**
* Suite style name.
*/
final override val styleName: String = "org.scalatest.fixture.PropSpec"
override def testDataFor(testName: String, theConfigMap: Map[String, Any] = Map.empty): TestData = createTestDataFor(testName, theConfigMap, this)
}