Class that supports the registration of a “subject” being specified and tested via the
instance referenced from FlatSpec
's behavior
field.”“
Class used via an implicit conversion to enable any two objects to be compared with
===
in assertions in tests.
Class that supports registration of ignored tests via the IgnoreWord
instance referenced
from FlatSpec
's ignore
field.
Class that supports registration of ignored, tagged tests via the IgnoreWord
instance referenced
from FlatSpec
's ignore
field.
Class that supports registration of ignored tests via the ItWord
instance
referenced from FlatSpec
's ignore
field.
Class that supports test registration in shorthand form.
Class that supports tagged test registration in shorthand form.
Class that supports test registration via the ItWord
instance referenced from FlatSpec
's it
field.
Class that supports the registration of tagged tests via the ItWord
instance
referenced from FlatSpec
's it
field.
Class that supports test (and shared test) registration via the instance referenced from FlatSpec
's it
field.
A test function taking no arguments, which also provides a test name and config map.
This class supports the syntax of FlatSpec
, WordSpec
, org.scalatest.fixture.FlatSpec
,
and org.scalatest.fixture.WordSpec
.
This class supports the syntax of FlatSpec
, WordSpec
, org.scalatest.fixture.FlatSpec
,
and org.scalatest.fixture.WordSpec
.
This class supports the syntax of FlatSpec
, WordSpec
, org.scalatest.fixture.FlatSpec
,
and org.scalatest.fixture.WordSpec
.
Assert that an Option[String]
is None
.
Assert that an Option[String]
is None
.
If the condition is None
, this method returns normally.
Else, it throws TestFailedException
with the String
value of the Some
included in the TestFailedException
's
detail message.
This form of assert
is usually called in conjunction with an
implicit conversion to Equalizer
, using a ===
comparison, as in:
assert(a === b)
For more information on how this mechanism works, see the documentation for
Equalizer
.
the Option[String]
to assert
Assert that an Option[String]
is None
.
Assert that an Option[String]
is None
.
If the condition is None
, this method returns normally.
Else, it throws TestFailedException
with the String
value of the Some
, as well as the
String
obtained by invoking toString
on the
specified message
,
included in the TestFailedException
's detail message.
This form of assert
is usually called in conjunction with an
implicit conversion to Equalizer
, using a ===
comparison, as in:
assert(a === b, "extra info reported if assertion fails")
For more information on how this mechanism works, see the documentation for
Equalizer
.
the Option[String]
to assert
An objects whose toString
method returns a message to include in a failure report.
Assert that a boolean condition, described in String
message
, is true.
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 the
String
obtained by invoking toString
on the
specified message
as the exception's detail message.
the boolean condition to assert
An objects whose toString
method returns a message to include in a failure report.
Assert that a boolean condition is true.
Assert that a boolean condition is true.
If the condition is true
, this method returns normally.
Else, it throws TestFailedException
.
the boolean condition to assert
Supports shared test registration in FlatSpec
s.
Supports shared test registration in FlatSpec
s.
This field supports syntax such as the following:
it should behave like nonFullStack(stackWithOneItem) ^
For more information and examples of the use of behave
, see the Shared tests section
in the main documentation for this trait.
Supports the registration of a “subject” being specified and tested.”“
Supports the registration of a “subject” being specified and tested.
This field enables syntax such as the following subject registration:
behavior of "A Stack"
^
For more information and examples of the use of the behavior
field, see the main documentation
for this trait.
Implicit conversion from Any
to Equalizer
, used to enable
assertions with ===
comparisons.
Implicit conversion from Any
to Equalizer
, used to enable
assertions with ===
comparisons.
For more information on this mechanism, see the documentation for Equalizer.
Because trait Suite
mixes in Assertions
, this implicit conversion will always be
available by default in ScalaTest Suite
s. This is the only implicit conversion that is in scope by default in every
ScalaTest Suite
. Other implicit conversions offered by ScalaTest, such as those that support the matchers DSL
or invokePrivate
, must be explicitly invited into your test code, either by mixing in a trait or importing the
members of its companion object. The reason ScalaTest requires you to invite in implicit conversions (with the exception of the
implicit conversion for ===
operator) is because if one of ScalaTest's implicit conversions clashes with an
implicit conversion used in the code you are trying to test, your program won't compile. Thus there is a chance that if you
are ever trying to use a library or test some code that also offers an implicit conversion involving a ===
operator,
you could run into the problem of a compiler error due to an ambiguous implicit conversion. If that happens, you can turn off
the implicit conversion offered by this convertToEqualizer
method simply by overriding the method in your
Suite
subclass, but not marking it as implicit:
// In your Suite subclass override def convertToEqualizer(left: Any) = new Equalizer(left)
the object whose type to convert to Equalizer
.
Implicitly converts an object of type ResultOfStringPassedToVerb
to an
InAndIgnoreMethods
, to enable in
and ignore
methods to be invokable on that object.
Implicitly converts an object of type ResultOfStringPassedToVerb
to an
InAndIgnoreMethods
, to enable in
and ignore
methods to be invokable on that object.
Implicitly converts an object of type ResultOfTaggedAsInvocation
to an
InAndIgnoreMethodsAfterTaggedAs
, to enable in
and ignore
methods to be invokable on that object.
Implicitly converts an object of type ResultOfTaggedAsInvocation
to an
InAndIgnoreMethodsAfterTaggedAs
, to enable in
and ignore
methods to be invokable on that object.
Implicitly converts an object of type String
to a StringCanWrapper
,
to enable can
methods to be invokable on that object.
Implicitly converts an object of type String
to a StringCanWrapper
,
to enable can
methods to be invokable on that object.
Implicitly converts an object of type String
to a StringMustWrapper
,
to enable must
methods to be invokable on that object.
Implicitly converts an object of type String
to a StringMustWrapper
,
to enable must
methods to be invokable on that object.
Implicitly converts an object of type String
to a StringShouldWrapperForVerb
,
to enable should
methods to be invokable on that object.
Implicitly converts an object of type String
to a StringShouldWrapperForVerb
,
to enable should
methods to be invokable on that object.
Executes one or more tests in this Suite
, printing results to the standard output.
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()
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 outputstopper
- 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 methoddistributor
- 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.
the name of one test to run.
a Map
of key-value pairs that can be used by the executing Suite
of tests.
a boolean that configures whether output is printed in color
a boolean that configures whether test and suite durations are printed to the standard output
a boolean that configures whether short stack traces should be printed for test failures
a boolean that configures whether full stack traces should be printed for test failures
a boolean that configures whether test and suite statistics are printed to the standard output
Expect that the value passed as expected
equals the value passed as actual
.
Expect that the value passed as expected
equals the value passed as actual
.
If the actual
value equals the expected
value
(as determined by ==
), expect
returns
normally. Else, expect
throws an
TestFailedException
whose detail message includes the expected and actual values.
the expected value
the actual value, which should equal the passed expected
value
Expect that the value passed as expected
equals the value passed as actual
.
Expect that the value passed as expected
equals the value passed as actual
.
If the actual
equals the expected
(as determined by ==
), expect
returns
normally. Else, if actual
is not equal to expected
, expect
throws an
TestFailedException
whose detail message includes the expected and actual values, as well as the String
obtained by invoking toString
on the passed message
.
the expected value
An object whose toString
method returns a message to include in a failure report.
the actual value, which should equal the passed expected
value
The total number of tests that are expected to run when this Suite
's run
method is invoked.
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:
testNames
List
, minus the number of tests marked as ignoredexpectedTestCount
on every nested Suite
contained in
nestedSuites
a Filter
with which to filter tests to count based on their tags
Throws TestFailedException
, with the passed
Throwable
cause, to indicate a test failed.
Throws TestFailedException
, with the passed
Throwable
cause, to indicate a test failed.
The getMessage
method of the thrown TestFailedException
will return cause.toString()
.
a Throwable
that indicates the cause of the failure.
Throws TestFailedException
, with the passed
String
message
as the exception's detail
message and Throwable
cause, to indicate a test failed.
Throws TestFailedException
, with the passed
String
message
as the exception's detail
message and Throwable
cause, to indicate a test failed.
A message describing the failure.
A Throwable
that indicates the cause of the failure.
Throws TestFailedException
, with the passed
String
message
as the exception's detail
message, to indicate a test failed.
Throws TestFailedException
, with the passed
String
message
as the exception's detail
message, to indicate a test failed.
A message describing the failure.
Throws TestFailedException
to indicate a test failed.
Throws TestFailedException
to indicate a test failed.
Supports registration of ignored tests in FlatSpec
s.
Supports registration of ignored tests in FlatSpec
s.
This field enables syntax such as the following registration of an ignored test:
ignore should "pop values in last-in-first-out order" in { ... }
^
For more information and examples of the use of the ignore
field, see the Ignored tests section
in the main documentation for this trait.
Returns an Informer
that during test execution will forward strings (and other objects) passed to its
apply
method to the current reporter.
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
FlatSpec
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.
Intercept and return an exception that's expected to be thrown by the passed function value.
Intercept and return an exception that's expected to
be thrown by the passed function value. The thrown exception must be an instance of the
type specified by the type parameter of this method. This method invokes the passed
function. If the function throws an exception that's an instance of the specified type,
this method returns that exception. Else, whether the passed function returns normally
or completes abruptly with a different exception, this method throws TestFailedException
.
Note that the type specified as this method's type parameter may represent any subtype of
AnyRef
, not just Throwable
or one of its subclasses. In
Scala, exceptions can be caught based on traits they implement, so it may at times make sense
to specify a trait that the intercepted exception's class must mix in. If a class instance is
passed for a type that could not possibly be used to catch an exception (such as String
,
for example), this method will complete abruptly with a TestFailedException
.
the function value that should throw the expected exception
an implicit Manifest
representing the type of the specified
type parameter.
the intercepted exception, if it is of the expected type
Supports test (and shared test) registration in FlatSpec
s.
Supports test (and shared test) registration in FlatSpec
s.
This field enables syntax such as the following test registration:
it should "pop values in last-in-first-out order" in { ... }
^
It also enables syntax such as the following shared test registration:
it should behave like nonEmptyStack(lastItemPushed) ^
For more information and examples of the use of the it
field, see the main documentation
for this trait.
A List
of this Suite
object's nested Suite
s.
A List
of this Suite
object's nested Suite
s. If this Suite
contains no nested Suite
s,
this method returns an empty List
. This trait's implementation of this method returns an empty List
.
Throws TestPendingException
to indicate a test is pending.
Throws TestPendingException
to indicate a test is pending.
A pending test is one that has been given a name but is not yet implemented. The purpose of pending tests is to facilitate a style of testing in which documentation of behavior is sketched out before tests are written to verify that behavior (and often, the before the behavior of the system being tested is itself implemented). Such sketches form a kind of specification of what tests and functionality to implement later.
To support this style of testing, a test can be given a name that specifies one
bit of behavior required by the system being tested. The test can also include some code that
sends more information about the behavior to the reporter when the tests run. At the end of the test,
it can call method pending
, which will cause it to complete abruptly with TestPendingException
.
Because tests in ScalaTest can be designated as pending with TestPendingException
, both the test name and any information
sent to the reporter when running the test can appear in the report of a test run. (In other words,
the code of a pending test is executed just like any other test.) However, because the test completes abruptly
with TestPendingException
, the test will be reported as pending, to indicate
the actual test, and possibly the functionality it is intended to test, has not yet been implemented.
Note: This method always completes abruptly with a TestPendingException
. Thus it always has a side
effect. Methods with side effects are usually invoked with parentheses, as in pending()
. This
method is defined as a parameterless method, in flagrant contradiction to recommended Scala style, because it
forms a kind of DSL for pending tests. It enables tests in suites such as FunSuite
or FunSpec
to be denoted by placing "(pending)
" after the test name, as in:
test("that style rules are not laws") (pending)
Readers of the code see "pending" in parentheses, which looks like a little note attached to the test name to indicate
it is pending. Whereas "(pending())
looks more like a method call, "(pending)
" lets readers
stay at a higher level, forgetting how it is implemented and just focusing on the intent of the programmer who wrote the code.
Execute the passed block of code, and if it completes abruptly, throw TestPendingException
, else
throw TestFailedException
.
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.
a block of code, which if it completes abruptly, should trigger a TestPendingException
Runs this suite of tests.
Runs this suite of tests.
If testName
is None
, this trait's implementation of this method
calls these two methods on this object in this order:
runNestedSuites(report, stopper, tagsToInclude, tagsToExclude, configMap, distributor)
runTests(testName, report, stopper, tagsToInclude, tagsToExclude, configMap)
If testName
is defined, then this trait's implementation of this method
calls runTests
, but does not call runNestedSuites
. This behavior
is part of the contract of this method. Subclasses that override run
must take
care not to call runNestedSuites
if testName
is defined. (The
OneInstancePerTest
trait depends on this behavior, for example.)
Subclasses and subtraits that override this run
method can implement them without
invoking either the runTests
or runNestedSuites
methods, which
are invoked by this trait's implementation of this method. It is recommended, but not required,
that subclasses and subtraits that override run
in a way that does not
invoke runNestedSuites
also override runNestedSuites
and make it
final. Similarly it is recommended, but not required,
that subclasses and subtraits that override run
in a way that does not
invoke runTests
also override runTests
(and runTest
,
which this trait's implementation of runTests
calls) and make it
final. The implementation of these final methods can either invoke the superclass implementation
of the method, or throw an UnsupportedOperationException
if appropriate. The
reason for this recommendation is that ScalaTest includes several traits that override
these methods to allow behavior to be mixed into a Suite
. For example, trait
BeforeAndAfterEach
overrides runTests
s. In a Suite
subclass that no longer invokes runTests
from run
, the
BeforeAndAfterEach
trait is not applicable. Mixing it in would have no effect.
By making runTests
final in such a Suite
subtrait, you make
the attempt to mix BeforeAndAfterEach
into a subclass of your subtrait
a compiler error. (It would fail to compile with a complaint that BeforeAndAfterEach
is trying to override runTests
, which is a final method in your trait.)
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
.
the Reporter
to which results will be reported
the Stopper
that will be consulted to determine whether to stop execution early.
a Filter
with which to filter tests based on their tags
a Map
of key-value pairs that can be used by the executing Suite
of tests.
an optional Distributor
, into which to put nested Suite
s to be run
by another entity, such as concurrently by a pool of threads. If None
, nested Suite
s will be run sequentially.
a Tracker
tracking Ordinal
s being fired by the current thread.
Run zero to many of this Suite
's nested Suite
s.
Run zero to many of this Suite
's nested Suite
s.
If the passed distributor
is None
, this trait's
implementation of this method invokes run
on each
nested Suite
in the List
obtained by invoking nestedSuites
.
If a nested Suite
's run
method completes abruptly with an exception, this trait's implementation of this
method reports that the Suite
aborted and attempts to run the
next nested Suite
.
If the passed distributor
is defined, this trait's implementation
puts each nested Suite
into the Distributor
contained in the Some
, in the order in which the
Suite
s appear in the List
returned by nestedSuites
, passing
in a new Tracker
obtained by invoking nextTracker
on the Tracker
passed to this method.
Implementations of this method are responsible for ensuring SuiteStarting
events
are fired to the Reporter
before executing any nested Suite
, and either SuiteCompleted
or SuiteAborted
after executing any nested Suite
.
the Reporter
to which results will be reported
the Stopper
that will be consulted to determine whether to stop execution early.
a Filter
with which to filter tests based on their tags
a Map
of key-value pairs that can be used by the executing Suite
of tests.
an optional Distributor
, into which to put nested Suite
s to be run
by another entity, such as concurrently by a pool of threads. If None
, nested Suite
s will be run sequentially.
a Tracker
tracking Ordinal
s being fired by the current thread.
Run a test.
Run a test. This trait's implementation runs the test registered with the name specified by
testName
. Each test's name is a concatenation of the text of all describers surrounding a test,
from outside in, and the test's spec text, with one space placed between each item. (See the documenation
for testNames
for an example.)
the name of one test to execute.
the Reporter
to which results will be reported
the Stopper
that will be consulted to determine whether to stop execution early.
a Map
of properties that can be used by this FlatSpec
's executing tests.
a Tracker
tracking Ordinal
s being fired by the current thread.
Run zero to many of this FlatSpec
's tests.
Run zero to many of this FlatSpec
's tests.
This method takes a testName
parameter that optionally specifies a test to invoke.
If testName
is Some
, this trait's implementation of this method
invokes runTest
on this object, passing in:
testName
- the String
value of the testName
Option
passed
to this methodreporter
- the Reporter
passed to this method, or one that wraps and delegates to itstopper
- the Stopper
passed to this method, or one that wraps and delegates to itconfigMap
- the configMap
passed to this method, or one that wraps and delegates to itThis method takes a Set
of tag names that should be included (tagsToInclude
), and a Set
that should be excluded (tagsToExclude
), when deciding which of this Suite
's tests to execute.
If tagsToInclude
is empty, all tests will be executed
except those those belonging to tags listed in the tagsToExclude
Set
. If tagsToInclude
is non-empty, only tests
belonging to tags mentioned in tagsToInclude
, and not mentioned in tagsToExclude
will be executed. However, if testName
is Some
, tagsToInclude
and tagsToExclude
are essentially ignored.
Only if testName
is None
will tagsToInclude
and tagsToExclude
be consulted to
determine which of the tests named in the testNames
Set
should be run. For more information on trait tags, see the main documentation for this trait.
If testName
is None
, this trait's implementation of this method
invokes testNames
on this Suite
to get a Set
of names of tests to potentially execute.
(A testNames
value of None
essentially acts as a wildcard that means all tests in
this Suite
that are selected by tagsToInclude
and tagsToExclude
should be executed.)
For each test in the testName
Set
, in the order
they appear in the iterator obtained by invoking the elements
method on the Set
, this trait's implementation
of this method checks whether the test should be run based on the tagsToInclude
and tagsToExclude
Set
s.
If so, this implementation invokes runTest
, passing in:
testName
- the String
name of the test to run (which will be one of the names in the testNames
Set
)reporter
- the Reporter
passed to this method, or one that wraps and delegates to itstopper
- the Stopper
passed to this method, or one that wraps and delegates to itconfigMap
- the configMap
passed to this method, or one that wraps and delegates to itan optional name of one test to execute. If None
, all relevant tests should be executed.
I.e., None
acts like a wildcard that means execute all relevant tests in this FlatSpec
.
the Reporter
to which results will be reported
the Stopper
that will be consulted to determine whether to stop execution early.
a Filter
with which to filter tests based on their tags
a Map
of key-value pairs that can be used by this FlatSpec
's executing tests.
an optional Distributor
, into which to put nested Suite
s to be run
by another entity, such as concurrently by a pool of threads. If None
, nested Suite
s will be run sequentially.
a Tracker
tracking Ordinal
s being fired by the current thread.
Supports the shorthand form of shared test registration.
Supports the shorthand form of shared test registration.
For example, this method enables syntax such as the following in:
"A Stack (with one item)" should behave like nonEmptyStack(stackWithOneItem, lastValuePushed)
^
This function is passed as an implicit parameter to a should
method
provided in ShouldVerb
, a must
method
provided in MustVerb
, and a can
method
provided in CanVerb
. When invoked, this function registers the
subject description (the parameter to the function) and returns a BehaveWord
.
Supports the shorthand form of test registration.
Supports the shorthand form of test registration.
For example, this method enables syntax such as the following:
"A Stack (when empty)" should "be empty" in { ... } ^
This function is passed as an implicit parameter to a should
method
provided in ShouldVerb
, a must
method
provided in MustVerb
, and a can
method
provided in CanVerb
. When invoked, this function registers the
subject description (the first parameter to the function) and returns a ResultOfStringPassedToVerb
initialized with the verb and rest parameters (the second and third parameters to
the function, respectively).
A user-friendly suite name for this 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 Report
s to pass to the suiteStarting
, suiteCompleted
,
and suiteAborted
methods of the Reporter
.
this Suite
object's suite name.
A Map
whose keys are String
tag names to which tests in this FlatSpec
belong, and values
the Set
of test names that belong to each tag.
A Map
whose keys are String
tag names to which tests in this FlatSpec
belong, and values
the Set
of test names that belong to each tag. If this FlatSpec
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
.
An immutable Set
of test names.
An immutable Set
of test names. If this FlatSpec
contains no tests, this method returns an
empty Set
.
This trait's implementation of this method will return a set that contains the names of all registered tests. The set's
iterator will return those names in the order in which the tests were registered. Each test's name is composed
of the concatenation of the text of each surrounding describer, in order from outside in, and the text of the
example itself, with all components separated by a space. For example, consider this FlatSpec
:
import org.scalatest.FlatSpec
class StackSpec extends FlatSpec {
"A Stack (when not empty)" must "allow me to pop" in {} it must "not be empty" in {}
"A Stack (when not full)" must "allow me to push" in {} it must "not be full" in {} }
Invoking testNames
on this FlatSpec
will yield a set that contains the following
two test name strings:
"A Stack (when not empty) must allow me to pop" "A Stack (when not empty) must not be empty" "A Stack (when not full) must allow me to push" "A Stack (when not full) must not be full"
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.
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
Run the passed test function in the context of a fixture established by this method.
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 var
s in this Suite
or initializing
a globally accessible external database. If you want to avoid reassigning instance var
s
you can use fixture.Suite.
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.
the no-arg test function to run with a fixture
Trait that facilitates a “behavior-driven” style of development (BDD), in which tests are combined with text that specifies the behavior the tests verify. (In BDD, the word example is usually used instead of test. The word test will not appear in your code if you use
FlatSpec
, so if you prefer the word example you can use it. However, in this documentation the word test will be used, for clarity and to be consistent with the rest of ScalaTest.) TraitFlatSpec
is so named because your specification text and tests line up flat against the left-side indentation level, with no nesting needed.FlatSpec
's no-nesting approach contrasts with traitsFunSpec
andWordSpec
, which use nesting to reduce duplication of specification text. Although nesting does have the advantage of reducing text duplication, figuring out the full specification text for one test can require back-tracking out of several levels of nesting, mentally prepending each fragment of text encountered. Thus the tradeoff with the nesting approach ofFunSpec
andWordSpec
is that they have less duplicated text at the cost of being a bit challenging to read. TraitFlatSpec
offers the opposite tradeoff. In aFlatSpec
text is duplicated more, but figuring out the full specification text for a particular test is easier. Here's an exampleFlatSpec
:Note: you can you
must
orcan
as well asshould
in aFlatSpec
. For example, instead ofit should "pop
..., you could writeit must "pop
... orit can "pop
....Instead of using a
behavior of
clause, you can alternatively use a shorthand syntax in which you replace the firstit
with the subject string, like this:Running either of the two previous three versions of
StackSpec
in the Scala interpreter would yield:A Stack - should pop values in last-in-first-out order - should throw NoSuchElementException if an empty stack is popped
In a
FlatSpec
you write a one (or more) sentence specification for each bit of behavior you wish to specify and test. Each specification sentence has a "subject," which is sometimes called the system under test (or SUT). The subject is the entity being specified and tested and also serves as the subject of the sentences you write for each test. Often you will want to write multiple tests for the same subject. In aFlatSpec
, you name the subject once, with abehavior of
clause or its shorthand, then write tests for that subject withit should
/must
can "do something"
phrases. Eachit
refers to the most recently declared subject. For example, the four tests shown in this snippet are all testing a stack that contains one item:The same is true if the tests are written using the shorthand notation:
In a
FlatSpec
, therefore, to figure out what "it
" means, you just scan vertically until you find the most recent use ofbehavior of
or the shorthand notation.A
FlatSpec
's lifecycle has two phases: the registration phase and the ready phase. It starts in registration phase and enters ready phase the first timerun
is called on it. It then remains in ready phase for the remainder of its lifetime.Tests can only be registered while the
FlatSpec
is in its registration phase. Any attempt to register a test after theFlatSpec
has entered its ready phase, i.e., afterrun
has been invoked on theFlatSpec
, will be met with a thrownTestRegistrationClosedException
. The recommended style of usingFlatSpec
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 aTestRegistrationClosedException
.See also: Getting started with
FlatSpec
.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,
FlatSpec
provides a methodignore
that can be used instead ofit
to register a test. For example, to temporarily disable the test with the name"A Stack should throw NoSuchElementException if an empty stack is popped"
, just change “it
” into “ignore
,” like this:If you run this version of
StackSpec
with:It will run only the first test and report that the second test was ignored:
When using shorthand notation, you won't have an
it
to change intoignore
for the first test of each new subject. To ignore such tests, you must instead changein
toignore
. For example, to temporarily disable the test with the name"A Stack should pop values in last-in-first-out order"
, change “in
” into “ignore
” like this:If you run this version of
StackSpec
with:It will run only the second test and report that the first test was ignored:
Informers
One of the parameters to the
run
method is aReporter
, 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 theReporter
as the suite runs. Most often the reporting done by default byFlatSpec
's methods will be sufficient, but occasionally you may wish to provide custom information to theReporter
from a test. For this purpose, anInformer
that will forward information to the currentReporter
is provided via theinfo
parameterless method. You can pass the extra information to theInformer
via itsapply
method. TheInformer
will then pass the information to theReporter
via anInfoProvided
event. Here's an example:If you run this
FlatSpec
from the interpreter, you will see the following message included in the printed report:scala> (new ArithmeticSpec).execute() The Scala language - must add correctly + addition seems to work - must subtract correctly
One use case for the
Informer
is to pass more information about a specification to the reporter. For example, theGivenWhenThen
trait provides methods that use the implicitinfo
provided byFlatSpec
to pass such information to the reporter. Here's an example:scala> (new ArithmeticSpec).execute() The Scala language - must add correctly + Given two integers + When they are added + Then the result is the sum of the two numbers - must subtract correctly + Given two integers + When one is subtracted from the other + Then the result is the difference of the two numbers
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 withTestPendingException
.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 withTestPendingException
, 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 inFlatSpec
like this:If you run this version of
ArithmeticSpec
with:It will run both tests but report that
The Scala language must subtract correctly
is pending. You'll see: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 thepending
method does). Thus the body of pending tests are executed up until they throwTestPendingException
. The reason for this difference is that it enables your unfinished test to sendInfoProvided
messages to the reporter before it completes abruptly withTestPendingException
, as shown in the previous example onInformer
s that used theGivenWhenThen
trait. For example, the following snippet in aFlatSpec
:Would yield the following output when run in the interpreter:
Tagging tests
A
FlatSpec
's tests may be classified into groups by tagging them with string names. As with any suite, when executing aFlatSpec
, groups of tests can optionally be included and/or excluded. To tag aFlatSpec
's tests, you pass objects that extend abstract classorg.scalatest.Tag
totaggedAs
method invoked on the string that describes the test you want to tag. ClassTag
takes one parameter, a string name. If you have created Java annotation interfaces for use as group names in direct subclasses oforg.scalatest.Suite
, then you will probably want to use group names on yourFlatSpec
s that match. To do so, simply pass the fully qualified names of the Java interfaces to theTag
constructor. For example, if you've defined Java annotation interfaces with fully qualified names,com.mycompany.tags.SlowTest
andcom.mycompany.tags.DbTest
, then you could create matching groups forFlatSpec
s like this:Given these definitions, you could place
FlatSpec
tests into groups like this:This code marks both tests with the
com.mycompany.tags.SlowTest
tag, and test"The Scala language should subtract correctly"
with thecom.mycompany.tags.DbTest
tag.The
run
method takes aFilter
, whose constructor takes an optionalSet[String]
calledtagsToInclude
and aSet[String]
calledtagsToExclude
. IftagsToInclude
isNone
, all tests will be run except those those belonging to tags listed in thetagsToExclude
Set
. IftagsToInclude
is defined, only tests belonging to tags mentioned in thetagsToInclude
set, and not mentioned intagsToExclude
, will be run.Shared fixtures
A test fixture is objects or other artifacts (such as files, sockets, database connections, etc.) used by tests to do their work. If a fixture is used by only one test method, then the definitions of the fixture objects can be local to the method, such as the objects assigned to
sum
anddiff
in the previousExampleSpec
examples. If multiple methods need to share an immutable fixture, one approach is to assign them to instance variables.In some cases, however, shared mutable fixture objects may be changed by test methods such that they need to be recreated or reinitialized before each test. Shared resources such as files or database connections may also need to be created and initialized before, and cleaned up after, each test. JUnit 3 offered methods
setUp
andtearDown
for this purpose. In ScalaTest, you can use theBeforeAndAfterEach
trait, which will be described later, to implement an approach similar to JUnit'ssetUp
andtearDown
, however, this approach usually involves reassigningvar
s or mutating objects between tests. Before going that route, you may wish to consider some more functional approaches that avoid side effects.Calling create-fixture methods
One approach is to write one or more create-fixture methods that return a new instance of a needed fixture object (or an holder object containing multiple needed fixture objects) each time it is called. You can then call a create-fixture method at the beginning of each test method that needs the fixture, storing the returned object or objects in local variables. Here's an example:
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.Instantiating fixture traits
A related technique is to place the fixture objects in a fixture trait and run your test code in the context of a new anonymous class instance that mixes in the fixture trait, like this:
Mixing in
OneInstancePerTest
If every test method requires the same set of mutable fixture objects, one other approach you can take is make them simply
val
s and mix in traitOneInstancePerTest
. If you mix inOneInstancePerTest
, each test will be run in its own instance of theSuite
, similar to the way JUnit tests are executed. Here's an example:Although the create-fixture, fixture-trait, and
OneInstancePerTest
approaches take care of setting up a fixture before each test, they don't address the problem of cleaning up a fixture after the test completes. In this situation, you'll need to either use side effects or the loan pattern.Mixing in
BeforeAndAfter
One way to use side effects is to mix in the
BeforeAndAfter
trait. With this trait you can denote a bit of code to run before each test withbefore
and/or after each test each test withafter
, like this:Overriding
withFixture(NoArgTest)
An alternate way to take care of setup and cleanup via side effects is to override
withFixture
. TraitSuite
's implementation ofrunTest
, which is inherited by this trait, passes a no-arg test function towithFixture
. It iswithFixture
's responsibility to invoke that test function.Suite
's implementation ofwithFixture
simply invokes the function, like this:You can, therefore, override
withFixture
to perform setup before, and cleanup after, invoking the test function. If you have cleanup to perform, you should invoke the test function inside atry
block and perform the cleanup in afinally
clause. Here's an example:Note that the
NoArgTest
passed towithFixture
, in addition to anapply
method that executes the test, also includes the test name as well as the config map passed torunTest
. Thus you can also use the test name and configuration objects inwithFixture
.The reason you should perform cleanup in a
finally
clause is thatwithFixture
is called byrunTest
, which expects an exception to be thrown to indicate a failed test. Thus when you invoke thetest
function insidewithFixture
, it may complete abruptly with an exception. Thefinally
clause will ensure the fixture cleanup happens as that exception propagates back up the call stack torunTest
.Overriding
withFixture(OneArgTest)
To use the loan pattern, you can extend
fixture.FlatSpec
(from theorg.scalatest.fixture
package) instead ofFlatSpec
. Each test in afixture.FlatSpec
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 specifyingFixtureParam
, and implement awithFixture
method that takes aOneArgTest
. ThiswithFixture
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. Here's an example:For more information, see the documentation for
fixture.FlatSpec
.Providing different fixtures to different tests
If different tests in the same
FlatSpec
require different fixtures, you can combine the previous techniques and provide each test with just the fixture or fixtures it needs. Here's an example in which aStringBuilder
and aListBuffer
are provided via fixture traits, and file writer (that requires cleanup) is provided via the loan pattern:In the previous example,
ScalaTest should be productive
uses only theStringBuilder
fixture, so it just instantiates anew Builder
, whereasit should be readable
uses only theListBuffer
fixture, so it just intantiates anew Buffer
.it should be user-friendly
needs just theFileWriter
fixture, so it invokeswithWriter
, which prepares and passes aFileWriter
to the test (and takes care of closing it afterwords).Two tests need multiple fixtures:
Test code should be clear and concise
needs both theStringBuilder
and theListBuffer
, so it instantiates a class that mixes in both fixture traits withnew Builder with Buffer
.it should be composable
needs all three fixtures, so in addition tonew Builder with Buffer
it also invokeswithWriter
, wrapping just the of the test code that needs the fixture.Note that in this case, the loan pattern is being implemented via the
withWriter
method that takes a function, not by overridingfixture.FlatSpec
'swithFixture(OneArgTest)
method.fixture.FlatSpec
makes the most sense if all (or at least most) tests need the same fixture, whereas in thisSuite
only two tests need theFileWriter
.In the previous example, the
withWriter
method passed an object into the tests. Passing fixture objects into tests is generally a good idea when possible, but sometimes a side affect is unavoidable. For example, if you need to initialize a database running on a server across a network, your with-fixture method will likely have nothing to pass. In such cases, simply create a with-fixture method that takes a by-name parameter and performs setup and cleanup via side effects, like this:You can then use it like:
Composing stackable fixture 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 callsuper.withFixture
. Here's an example in which theStringBuilder
andListBuffer[String]
fixtures used in the previous examples have been factored out into two stackable fixture traits namedBuilder
andBuffer
:By mixing in both the
Builder
andBuffer
traits,ExampleSpec
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 wantedBuffer
to be "super" toBuilder
, you need only switch the order you mix them together, like this:And if you only need one fixture you mix in only that trait:
Another way to create stackable fixture traits is by extending the
BeforeAndAfterEach
and/orBeforeAndAfterAll
traits.BeforeAndAfterEach
has abeforeEach
method that will be run before each test (like JUnit'ssetUp
), and anafterEach
method that will be run after (like JUnit'stearDown
). Similarly,BeforeAndAfterAll
has abeforeAll
method that will be run before all tests, and anafterAll
method that will be run after all tests. Here's what the previously shown example would look like if it were rewritten to use theBeforeAndAfterEach
methods instead ofwithFixture
:To get the same ordering as
withFixture
, place yoursuper.beforeEach
call at the end of eachbeforeEach
method, and thesuper.afterEach
call at the beginning of eachafterEach
method, as shown in the previous example. It is a good idea to invokesuper.afterEach
in atry
block and perform cleanup in afinally
clause, as shown in the previous example, because this ensures the cleanup code is performed even ifsuper.afterAll
throws an exception.One difference to bear in mind between the before-and-after traits and the
withFixture
methods, is that if awithFixture
method completes abruptly with an exception, it is considered a failed test. By contrast, if any of the methods on the before-and-after traits (i.e.,before
andafter
ofBeforeAndAfter
,beforeEach
andafterEach
ofBeforeAndAfterEach
, andbeforeAll
andafterAll
ofBeforeAndAfterAll
) complete abruptly, it is considered a failed suite, which will result in aSuiteAborted
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
FlatSpec
, you first place shared tests in behavior functions. These behavior functions will be invoked during the construction phase of anyFlatSpec
that uses them, so that the tests they contain will be registered as tests in thatFlatSpec
. For example, given this stack class: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 yourFlatSpec
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 theFlatSpec
that uses them. If they are shared between differentFlatSpec
s, however, you could also define them in a separate trait that is mixed into eachFlatSpec
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:Given these behavior functions, you could invoke them directly, but
FlatSpec
offers a DSL for the purpose, which looks like this:If you prefer to use an imperative style to change fixtures, for example by mixing in
BeforeAndAfterEach
and reassigning astack
var
inbeforeEach
, you could write your behavior functions in the context of thatvar
, 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:it should behave like nonEmptyStack // assuming lastValuePushed is also in scope inside nonEmptyStack it should behave like nonFullStack
The recommended style, however, is the functional, pass-all-the-needed-values-in style. Here's an example:
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> (new SharedTestExampleSpec).execute() A Stack (when empty) - should be empty - should complain on peek - should complain on pop A Stack (with one item) - should be non-empty - should return the top item on peek - should not remove the top item on peek - should remove the top item on pop - should not be full - should add to the top on push A Stack (with one item less than capacity) - should be non-empty - should return the top item on peek - should not remove the top item on peek - should remove the top item on pop - should not be full - should add to the top on push A Stack (full) - should be full - should be non-empty - should return the top item on peek - should not remove the top item on peek - should 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
WordSpec
is to make sure each invocation of a behavior function is in the context of a different set ofwhen
, verb (should
,must
, or can), andthat
clauses, which will prepend a string to each test name. For example, the following code in aWordSpec
would register a test with the name"A Stack (when empty) should be empty"
:Or, using the shorthand notation:
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 combination ofwhen
, verb, andthat
clauses.