Helper class used by code generated by the assert
macro.
Helper class used by code generated by the assert
macro.
A class that via an implicit conversion (named convertToFreeSpecStringWrapper
) enables
methods in
, is
, taggedAs
and ignore
,
as well as the dash operator (-
), to be invoked on String
s.
A class that via an implicit conversion (named convertToFreeSpecStringWrapper
) enables
methods in
, is
, taggedAs
and ignore
,
as well as the dash operator (-
), to be invoked on String
s.
A test function taking no arguments and returning a FutureOutcome
.
A test function taking no arguments and returning a FutureOutcome
.
For more detail and examples, see the relevant section in the
documentation for trait AsyncFlatSpec
.
Class that provides the lastly
method of the complete
-lastly
syntax.
Class that provides the lastly
method of the complete
-lastly
syntax.
Class that supports the registration of tagged tests.
Class that supports the registration of tagged tests.
Instances of this class are returned by the taggedAs
method of
class FreeSpecStringWrapper
.
Returns an Alerter
that during test execution will forward strings passed to its
apply
method to the current reporter.
Returns an Alerter
that during test execution will forward strings passed to its
apply
method to the current reporter. If invoked in a constructor, it
will register the passed string for forwarding later during test execution. If invoked while this
FreeSpec
is being executed, such as from inside a test function, it will forward the information to
the current reporter immediately. If invoked at any other time, it will
print to the standard output. This method can be called safely by any thread.
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 a helpful error message
appended with the String
obtained by invoking toString
on the
specified clue
as the exception's detail message.
This method is implemented in terms of a Scala macro that will generate a more helpful error message for expressions of this form:
At this time, any other form of expression will just get a TestFailedException
with message saying the given
expression was false. In the future, we will enhance this macro to give helpful error messages in more situations.
In ScalaTest 2.0, however, this behavior was sufficient to allow the ===
that returns Boolean
to be the default in tests. This makes ===
consistent between tests and production
code.
the boolean condition to assert
An objects whose toString
method returns a message to include in a failure report.
NullArgumentException
if message
is null
.
TestFailedException
if the condition is false
.
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
.
This method is implemented in terms of a Scala macro that will generate a more helpful error message for expressions of this form:
At this time, any other form of expression will get a TestFailedException
with message saying the given
expression was false. In the future, we will enhance this macro to give helpful error messages in more situations.
In ScalaTest 2.0, however, this behavior was sufficient to allow the ===
that returns Boolean
to be the default in tests. This makes ===
consistent between tests and production
code.
the boolean condition to assert
TestFailedException
if the condition is false
.
Asserts that a given string snippet of code passes both the Scala parser and type checker.
Asserts that a given string snippet of code passes both the Scala parser and type checker.
You can use this to make sure a snippet of code compiles:
assertCompiles("val a: Int = 1")
Although assertCompiles
is implemented with a macro that determines at compile time whether
the snippet of code represented by the passed string compiles, errors (i.e.,
snippets of code that do not compile) are reported as test failures at runtime.
the snippet of code that should compile
Asserts that a given string snippet of code does not pass either the Scala parser or type checker.
Asserts that a given string snippet of code does not pass either the Scala parser or type checker.
Often when creating libraries you may wish to ensure that certain arrangements of code that
represent potential “user errors” do not compile, so that your library is more error resistant.
ScalaTest's Assertions
trait includes the following syntax for that purpose:
assertDoesNotCompile("val a: String = \"a string")
Although assertDoesNotCompile
is implemented with a macro that determines at compile time whether
the snippet of code represented by the passed string doesn't compile, errors (i.e.,
snippets of code that do compile) are reported as test failures at runtime.
Note that the difference between assertTypeError
and assertDoesNotCompile
is
that assertDoesNotCompile
will succeed if the given code does not compile for any reason,
whereas assertTypeError
will only succeed if the given code does not compile because of
a type error. If the given code does not compile because of a syntax error, for example, assertDoesNotCompile
will return normally but assertTypeError
will throw a TestFailedException
.
the snippet of code that should not type check
Assert that the value passed as expected
equals the value passed as actual
.
Assert that the value passed as expected
equals the value passed as actual
.
If the actual
value equals the expected
value
(as determined by ==
), assertResult
returns
normally. Else, assertResult
throws a
TestFailedException
whose detail message includes the expected and actual values.
the expected value
the actual value, which should equal the passed expected
value
TestFailedException
if the passed actual
value does not equal the passed expected
value.
Assert that the value passed as expected
equals the value passed as actual
.
Assert that the value passed as expected
equals the value passed as actual
.
If the actual
equals the expected
(as determined by ==
), assertResult
returns
normally. Else, if actual
is not equal to expected
, assertResult
throws a
TestFailedException
whose detail message includes the expected and actual values, as well as the String
obtained by invoking toString
on the passed clue
.
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
TestFailedException
if the passed actual
value does not equal the passed expected
value.
Ensure that an expected exception is thrown by the passed function value.
Ensure that an expected exception is thrown by the passed function value. The thrown exception must be an instance of the
type specified by the type parameter of this method. This method invokes the passed
function. If the function throws an exception that's an instance of the specified type,
this method returns Succeeded
. Else, whether the passed function returns normally
or completes abruptly with a different exception, this method throws TestFailedException
.
Note that the type specified as this method's type parameter may represent any subtype of
AnyRef
, not just Throwable
or one of its subclasses. In
Scala, exceptions can be caught based on traits they implement, so it may at times make sense
to specify a trait that the intercepted exception's class must mix in. If a class instance is
passed for a type that could not possibly be used to catch an exception (such as String
,
for example), this method will complete abruptly with a TestFailedException
.
Also note that the difference between this method and intercept
is that this method
does not return the expected exception, so it does not let you perform further assertions on
that exception. Instead, this method returns Succeeded
, which means it can
serve as the last statement in an async- or safe-style suite. It also indicates to the reader
of the code that nothing further is expected about the thrown exception other than its type.
The recommended usage is to use assertThrows
by default, intercept
only when you
need to inspect the caught exception further.
the function value that should throw the expected exception
an implicit ClassTag
representing the type of the specified
type parameter.
the Succeeded
singleton, if an exception of the expected type is thrown
TestFailedException
if the passed function does not complete abruptly with an exception
that's an instance of the specified type.
Asserts that a given string snippet of code does not pass the Scala type checker, failing if the given snippet does not pass the Scala parser.
Asserts that a given string snippet of code does not pass the Scala type checker, failing if the given snippet does not pass the Scala parser.
Often when creating libraries you may wish to ensure that certain arrangements of code that
represent potential “user errors” do not compile, so that your library is more error resistant.
ScalaTest's Assertions
trait includes the following syntax for that purpose:
assertTypeError("val a: String = 1")
Although assertTypeError
is implemented with a macro that determines at compile time whether
the snippet of code represented by the passed string type checks, errors (i.e.,
snippets of code that do type check) are reported as test failures at runtime.
Note that the difference between assertTypeError
and assertDoesNotCompile
is
that assertDoesNotCompile
will succeed if the given code does not compile for any reason,
whereas assertTypeError
will only succeed if the given code does not compile because of
a type error. If the given code does not compile because of a syntax error, for example, assertDoesNotCompile
will return normally but assertTypeError
will throw a TestFailedException
.
the snippet of code that should not type check
Helper instance used by code generated by macro assertion.
Helper instance used by code generated by macro assertion.
Assume that a boolean condition, described in String
message
, is true.
Assume that a boolean condition, described in String
message
, is true.
If the condition is true
, this method returns normally.
Else, it throws TestCanceledException
with a helpful error message
appended with String
obtained by invoking toString
on the
specified clue
as the exception's detail message.
This method is implemented in terms of a Scala macro that will generate a more helpful error message for expressions of this form:
At this time, any other form of expression will just get a TestCanceledException
with message saying the given
expression was false. In the future, we will enhance this macro to give helpful error messages in more situations.
In ScalaTest 2.0, however, this behavior was sufficient to allow the ===
that returns Boolean
to be the default in tests. This makes ===
consistent between tests and production
code.
the boolean condition to assume
An objects whose toString
method returns a message to include in a failure report.
NullArgumentException
if message
is null
.
TestCanceledException
if the condition is false
.
Assume that a boolean condition is true.
Assume that a boolean condition is true.
If the condition is true
, this method returns normally.
Else, it throws TestCanceledException
.
This method is implemented in terms of a Scala macro that will generate a more helpful error message for expressions of this form:
At this time, any other form of expression will just get a TestCanceledException
with message saying the given
expression was false. In the future, we will enhance this macro to give helpful error messages in more situations.
In ScalaTest 2.0, however, this behavior was sufficient to allow the ===
that returns Boolean
to be the default in tests. This makes ===
consistent between tests and production
code.
the boolean condition to assume
TestCanceledException
if the condition is false
.
Supports shared test registration in FreeSpec
s.
Supports shared test registration in FreeSpec
s.
This field enables syntax such as the following:
behave like nonFullStack(stackWithOneItem) ^
For more information and examples of the use of <cod>behave, see the Shared tests section in the main documentation for this trait.
Throws TestCanceledException
, with the passed
Throwable
cause, to indicate a test failed.
Throws TestCanceledException
, with the passed
Throwable
cause, to indicate a test failed.
The getMessage
method of the thrown TestCanceledException
will return cause.toString
.
a Throwable
that indicates the cause of the cancellation.
NullArgumentException
if cause
is null
Throws TestCanceledException
, with the passed
String
message
as the exception's detail
message and Throwable
cause, to indicate a test failed.
Throws TestCanceledException
, with the passed
String
message
as the exception's detail
message and Throwable
cause, to indicate a test failed.
A message describing the failure.
A Throwable
that indicates the cause of the failure.
NullArgumentException
if message
or cause
is null
Throws TestCanceledException
, with the passed
String
message
as the exception's detail
message, to indicate a test was canceled.
Throws TestCanceledException
, with the passed
String
message
as the exception's detail
message, to indicate a test was canceled.
A message describing the cancellation.
NullArgumentException
if message
is null
Throws TestCanceledException
to indicate a test was canceled.
Throws TestCanceledException
to indicate a test was canceled.
Registers a block of code that produces any "futuristic" type (any type F
for which
an implicit Futuristic[F]
instance is implicitly available), returning
an object that offers a lastly
method.
Registers a block of code that produces any "futuristic" type (any type F
for which
an implicit Futuristic[F]
instance is implicitly available), returning
an object that offers a lastly
method.
See the main documentation for trait CompleteLastly
for more detail.
cleanup code to execute whether the code passed to complete
throws an exception or succesfully returns a futuristic value.
Implicitly converts an Assertion
to a Future[Assertion]
.
Implicitly converts an Assertion
to a Future[Assertion]
.
This implicit conversion is used to allow synchronous tests to be included along with
asynchronous tests in an AsyncTestSuite
. It will be
the Assertion
to convert
a Future[Assertion]
that has already completed successfully
(containing the Succeeded
singleton).
Implicitly converts String
s to FreeSpecStringWrapper
, which enables
methods in
, is
, taggedAs
and ignore
,
as well as the dash operator (-
), to be invoked on String
s.
Implicitly converts String
s to FreeSpecStringWrapper
, which enables
methods in
, is
, taggedAs
and ignore
,
as well as the dash operator (-
), to be invoked on String
s.
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()
(The above syntax actually invokes the overloaded parameterless form of execute
, which calls this form with its default parameter values.)
To run just the test named "my favorite test"
in a suite from the Scala interpreter, you would write:
scala> (new ExampleSuite).execute("my favorite test")
Or:
scala> (new ExampleSuite).execute(testName = "my favorite test")
The configMap
parameter
If you provide a value for the configMap
parameter, this method will pass it to run
. If not, the default value
of an empty Map
will be passed. For more information on how to use a config map to configure your test suites, see
the config map section in the main documentation for this trait. Here's an example in which you configure
a run with the name of an input file:
scala> (new ExampleSuite).execute(configMap = Map("inputFileName" -> "in.txt")
The color
parameter
If you leave the color
parameter unspecified, this method will configure the reporter it passes to run
to print
to the standard output in color (via ansi escape characters). If you don't want color output, specify false for color
, like this:
scala> (new ExampleSuite).execute(color = false)
The durations
parameter
If you leave the durations
parameter unspecified, this method will configure the reporter it passes to run
to
not print durations for tests and suites to the standard output. If you want durations printed, specify true for durations
,
like this:
scala> (new ExampleSuite).execute(durations = true)
The shortstacks
and fullstacks
parameters
If you leave both the shortstacks
and fullstacks
parameters unspecified, this method will configure the reporter
it passes to run
to not print stack traces for failed tests if it has a stack depth that identifies the offending
line of test code. If you prefer a short stack trace (10 to 15 stack frames) to be printed with any test failure, specify true for
shortstacks
:
scala> (new ExampleSuite).execute(shortstacks = true)
For full stack traces, set fullstacks
to true:
scala> (new ExampleSuite).execute(fullstacks = true)
If you specify true for both shortstacks
and fullstacks
, you'll get full stack traces.
The stats
parameter
If you leave the stats
parameter unspecified, this method will not fire RunStarting
and either RunCompleted
or RunAborted
events to the reporter it passes to run
.
If you specify true for stats
, this method will fire the run events to the reporter, and the reporter will print the
expected test count before the run, and various statistics after, including the number of suites completed and number of tests that
succeeded, failed, were ignored or marked pending. Here's how you get the stats:
scala> (new ExampleSuite).execute(stats = true)
To summarize, this method will pass to run
:
testName
- None
if this method's testName
parameter is left at its default value of null
, else Some(testName)
.reporter
- a reporter that prints to the standard 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
IllegalArgumentException
if testName
is defined, but no test with the specified test name
exists in this Suite
NullArgumentException
if the passed configMap
parameter is null
.
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 ignored and
any tests that are exluded by the passed Filter
expectedTestCount
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.
NullArgumentException
if cause
is null
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.
NullArgumentException
if message
or cause
is null
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.
NullArgumentException
if message
is null
Throws TestFailedException
to indicate a test failed.
Throws TestFailedException
to indicate a test failed.
Returns an Informer
that during test execution will forward strings passed to its
apply
method to the current reporter.
Returns an Informer
that during test execution will forward strings passed to its
apply
method to the current reporter. If invoked in a constructor, it
will register the passed string for forwarding later during test execution. If invoked from inside a scope,
it will forward the information to the current reporter immediately. If invoked from inside a test function,
it will record the information and forward it to the current reporter only after the test completed, as recordedEvents
of the test completed event, such as TestSucceeded
. If invoked at any other time, it will print to the standard output.
This method can be called safely by any thread.
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
.
Also note that the difference between this method and assertThrows
is that this method
returns the expected exception, so it lets you perform further assertions on
that exception. By contrast, the assertThrows
method returns Succeeded
, which means it can
serve as the last statement in an async- or safe-style suite. assertThrows
also indicates to the reader
of the code that nothing further is expected about the thrown exception other than its type.
The recommended usage is to use assertThrows
by default, intercept
only when you
need to inspect the caught exception further.
the function value that should throw the expected exception
an implicit ClassTag
representing the type of the specified
type parameter.
the intercepted exception, if it is of the expected type
TestFailedException
if the passed function does not complete abruptly with an exception
that's an instance of the specified type.
Returns a Documenter
that during test execution will forward strings passed to its
apply
method to the current reporter.
Returns a Documenter
that during test execution will forward strings passed to its
apply
method to the current reporter. If invoked in a constructor, it
will register the passed string for forwarding later during test execution. If invoked from inside a scope,
it will forward the information to the current reporter immediately. If invoked from inside a test function,
it will record the information and forward it to the current reporter only after the test completed, as recordedEvents
of the test completed event, such as TestSucceeded
. If invoked at any other time, it will print to the standard output.
This method can be called safely by any thread.
An immutable IndexedSeq
of this Suite
object's nested Suite
s.
An immutable IndexedSeq
of this Suite
object's nested Suite
s. If this Suite
contains no nested Suite
s,
this method returns an empty IndexedSeq
. This trait's implementation of this method returns an empty List
.
Returns a Notifier
that during test execution will forward strings passed to its
apply
method to the current reporter.
Returns a Notifier
that during test execution will forward strings passed to its
apply
method to the current reporter. If invoked in a constructor, it
will register the passed string for forwarding later during test execution. If invoked while this
FreeSpec
is being executed, such as from inside a test function, it will forward the information to
the current reporter immediately. If invoked at any other time, it will
print to the standard output. This method can be called safely by any thread.
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
TestPendingException
if the passed block of code completes abruptly with an Exception
or AssertionError
Transforms a future of any type into a Future[T]
, where T
is a given
expected exception type, which succeeds if the given future
completes with a Failure
containing the specified exception type.
Transforms a future of any type into a Future[T]
, where T
is a given
expected exception type, which succeeds if the given future
completes with a Failure
containing the specified exception type.
See the main documentation for this trait for more detail and examples.
A future of any type, which you expect to fail with an exception of the specified type T
a Future[T] containing on success the expected exception, or containing on failure
a TestFailedException
Transforms a future of any type into a Future[Assertion]
that succeeds if the future
completes with a Failure
containing the specified exception type.
Transforms a future of any type into a Future[Assertion]
that succeeds if the future
completes with a Failure
containing the specified exception type.
See the main documentation for this trait for more detail and examples.
A future of any type, which you expect to fail with an exception of the specified type T
a Future[Assertion] containing on success the Succeeded
singleton, or containing on failure
a TestFailedException
Registers a test.
Registers a test.
the test text
the test tags
the test function
Registers an ignored test.
Registers an ignored test.
the test text
the test tags
the test function
The fully qualified class name of the rerunner to rerun this suite.
The fully qualified class name of the rerunner to rerun this suite. This implementation will look at this.getClass and see if it is either an accessible Suite, or it has a WrapWith annotation. If so, it returns the fully qualified class name wrapped in a Some, or else it returns None.
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
runTests
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 Args
for this run
a Status
object that indicates when all tests and nested suites started by this method have completed, and whether or not a failure occurred.
IllegalArgumentException
if testName
is defined, but no test with the specified test name
exists in this Suite
NullArgumentException
if any passed parameter is null
.
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 Args
for this run
a Status
object that indicates when all nested suites started by this method have completed, and whether or not a failure occurred.
NullArgumentException
if any passed parameter is null
.
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 documentation
for testNames
for an example.)
the name of one test to execute.
the Args
for this run
a Status
object that indicates when the test started by this method has completed, and whether or not it failed .
NullArgumentException
if any of testName
, reporter
, stopper
, or configMap
is null
.
Run zero to many of this FreeSpec
's tests.
Run zero to many of this FreeSpec
'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 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 Args
for this run
a Status
object that indicates when all tests started by this method have completed, and whether or not a failure occurred.
IllegalArgumentException
if testName
is defined, but no test with the specified test name
exists in this Suite
NullArgumentException
if any of the passed parameters is null
.
Suite style name.
Suite style name.
The Succeeded
singleton.
The Succeeded
singleton.
You can use succeed
to solve a type error when an async test
does not end in either Future[Assertion]
or Assertion
.
Because Assertion
is a type alias for Succeeded.type
,
putting succeed
at the end of a test body (or at the end of a
function being used to map the final future of a test body) will solve
the type error.
A string ID for this Suite
that is intended to be unique among all suites reported during a run.
A string ID for this Suite
that is intended to be unique among all suites reported during a run.
This trait's
implementation of this method returns the fully qualified name of this object's class.
Each suite reported during a run will commonly be an instance of a different Suite
class,
and in such cases, this default implementation of this method will suffice. However, in special cases
you may need to override this method to ensure it is unique for each reported suite. For example, if you write
a Suite
subclass that reads in a file whose name is passed to its constructor and dynamically
creates a suite of tests based on the information in that file, you will likely need to override this method
in your Suite
subclass, perhaps by appending the pathname of the file to the fully qualified class name.
That way if you run a suite of tests based on a directory full of these files, you'll have unique suite IDs for
each reported suite.
The suite ID is intended to be unique, because ScalaTest does not enforce that it is unique. If it is not unique, then you may not be able to uniquely identify a particular test of a particular suite. This ability is used, for example, to dynamically tag tests as having failed in the previous run when rerunning only failed tests.
this Suite
object's ID.
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
names of tagged tests and whose associated values are
the Set
of tags for the test.
A Map
whose keys are String
names of tagged tests and whose associated values are
the Set
of tags for the test. If this FreeSpec
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
taggedAs
.
In addition, this trait's implementation will also auto-tag tests with class level annotations.
For example, if you annotate @Ignore
at the class level, all test methods in the class will be auto-annotated with
org.scalatest.Ignore
.
Provides a TestData
instance for the passed test name, given the passed config map.
Provides a TestData
instance for the passed test name, given the passed config map.
This method is used to obtain a TestData
instance to pass to withFixture(NoArgTest)
and withFixture(OneArgTest)
and the beforeEach
and afterEach
methods
of trait BeforeAndAfterEach
.
the name of the test for which to return a TestData
instance
the config map to include in the returned TestData
a TestData
instance for the specified test, which includes the specified config map
An immutable Set
of test names.
An immutable Set
of test names. If this FreeSpec
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 FreeSpec
:
import org.scalatest.FreeSpec class StackSpec extends FreeSpec { "A Stack" - { "when not empty" - { "must allow me to pop" in {} } "when not full" - { "must allow me to push" in {} } } }
Invoking testNames
on this FreeSpec
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 full must allow me to push"
Returns a user friendly string for this suite, composed of the
simple name of the class (possibly simplified further by removing dollar signs if added by the Scala interpeter) and, if this suite
contains nested suites, the result of invoking toString
on each
of the nested suites, separated by commas and surrounded by parentheses.
Returns a user friendly string for this suite, 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.
a user-friendly string for this suite
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
NullArgumentException
if the passed clue
is null
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, register a callback
on the resulting FutureOutcome
to perform any clean
up needed after the test completes. Because the NoArgAsyncTest
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.AsyncTestSuite.
This trait's implementation of runTest
invokes this method for each test, passing
in a NoArgAsyncTest
whose apply
method will execute the code of the test
and returns its result.
This trait's implementation of this method simply invokes the passed NoArgAsyncTest
function.
the no-arg async test function to run with a fixture
The parameterless execute
method has been deprecated and will be removed in a future version
of ScalaTest. Please invoke execute
with empty parens instead: execute()
.
The parameterless execute
method has been deprecated and will be removed in a future version
of ScalaTest. Please invoke execute
with empty parens instead: execute()
.
The original purpose of this method, which simply invokes the other overloaded form of execute
with default parameter values,
was to serve as a mini-DSL for the Scala interpreter. It allowed you to execute a Suite
in the
interpreter with a minimum of finger typing:
scala> org.scalatest.run(new SetSpec) An empty Set - should have size 0 - should produce NoSuchElementException when head is invoked !!! IGNORED !!!
However it uses postfix notation, which is now behind a language feature import. Thus better to use
the other execute
method or org.scalatest.run
:
(new ExampleSuite).execute() // or org.scalatest.run(new ExampleSuite)
The parameterless execute method has been deprecated and will be removed in a future version of ScalaTest. Please invoke execute with empty parens instead: execute().
Trap and return any thrown exception that would normally cause a ScalaTest test to fail, or create and return a new RuntimeException
indicating no exception is thrown.
Trap and return any thrown exception that would normally cause a ScalaTest test to fail, or create and return a new RuntimeException
indicating no exception is thrown.
This method is intended to be used in the Scala interpreter to eliminate large stack traces when trying out ScalaTest assertions and
matcher expressions. It is not intended to be used in regular test code. If you want to ensure that a bit of code throws an expected
exception, use intercept
, not trap
. Here's an example interpreter session without trap
:
scala> import org.scalatest._ import org.scalatest._ scala> import Matchers._ import Matchers._ scala> val x = 12 a: Int = 12 scala> x shouldEqual 13 org.scalatest.exceptions.TestFailedException: 12 did not equal 13 at org.scalatest.Assertions$class.newAssertionFailedException(Assertions.scala:449) at org.scalatest.Assertions$.newAssertionFailedException(Assertions.scala:1203) at org.scalatest.Assertions$AssertionsHelper.macroAssertTrue(Assertions.scala:417) at .<init>(<console>:15) at .<clinit>(<console>) at .<init>(<console>:7) at .<clinit>(<console>) at $print(<console>) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at scala.tools.nsc.interpreter.IMain$ReadEvalPrint.call(IMain.scala:731) at scala.tools.nsc.interpreter.IMain$Request.loadAndRun(IMain.scala:980) at scala.tools.nsc.interpreter.IMain.loadAndRunReq$1(IMain.scala:570) at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:601) at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:565) at scala.tools.nsc.interpreter.ILoop.reallyInterpret$1(ILoop.scala:745) at scala.tools.nsc.interpreter.ILoop.interpretStartingWith(ILoop.scala:790) at scala.tools.nsc.interpreter.ILoop.command(ILoop.scala:702) at scala.tools.nsc.interpreter.ILoop.processLine$1(ILoop.scala:566) at scala.tools.nsc.interpreter.ILoop.innerLoop$1(ILoop.scala:573) at scala.tools.nsc.interpreter.ILoop.loop(ILoop.scala:576) at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply$mcZ$sp(ILoop.scala:867) at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:822) at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:822) at scala.tools.nsc.util.ScalaClassLoader$.savingContextLoader(ScalaClassLoader.scala:135) at scala.tools.nsc.interpreter.ILoop.process(ILoop.scala:822) at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:83) at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:96) at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:105) at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)
That's a pretty tall stack trace. Here's what it looks like when you use trap
:
scala> trap { x shouldEqual 13 } res1: Throwable = org.scalatest.exceptions.TestFailedException: 12 did not equal 13
Much less clutter. Bear in mind, however, that if no exception is thrown by the
passed block of code, the trap
method will create a new NormalResult
(a subclass of Throwable
made for this purpose only) and return that. If the result was the Unit
value, it
will simply say that no exception was thrown:
scala> trap { x shouldEqual 12 } res2: Throwable = No exception was thrown.
If the passed block of code results in a value other than Unit
, the NormalResult
's toString
will print the value:
scala> trap { "Dude!" } res3: Throwable = No exception was thrown. Instead, result was: "Dude!"
Although you can access the result value from the NormalResult
, its type is Any
and therefore not
very convenient to use. It is not intended that trap
be used in test code. The sole intended use case for trap
is decluttering
Scala interpreter sessions by eliminating stack traces when executing assertion and matcher expressions.
The trap method is no longer needed for demos in the REPL, which now abreviates stack traces, and will be removed in a future version of ScalaTest
Enables testing of asynchronous code without blocking, using a style consistent with traditional
FreeSpec
tests.AsyncFreeSpec
is intended to enable users ofFreeSpec
to write non-blocking asynchronous tests that are consistent with their traditionalFreeSpec
tests. Note:AsyncFreeSpec
is intended for use in special situations where non-blocking asynchronous testing is needed, with classFreeSpec
used for general needs.Given a
Future
returned by the code you are testing, you need not block until theFuture
completes before performing assertions against its value. You can instead map those assertions onto theFuture
and return the resultingFuture[Assertion]
to ScalaTest. The test will complete asynchronously, when theFuture[Assertion]
completes.Here's an example
AsyncFreeSpec
:In an
AsyncFreeSpec
you write a test with a string followed byin
and the body of the test in curly braces, like this: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:
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. In short, you structure anAsyncFreeSpec
exactly like aFreeSpec
, but with tests having result typeAssertion
orFuture[Assertion]
. For more examples of structure, see the documentation forFreeSpec
.Starting with version 3.0.0, ScalaTest assertions and matchers have result type
Assertion
. The result type of the first test in the example above, therefore, isFuture[Assertion]
. For clarity, here's the relevant code in a REPL session:The second test has result type
Assertion
:When
AddSpec
is constructed, the second test will be implicitly converted toFuture[Assertion]
and registered. The implicit conversion is fromAssertion
toFuture[Assertion]
, so you must end synchronous tests in some ScalaTest assertion or matcher expression. If a test would not otherwise end in typeAssertion
, you can placesucceed
at the end of the test.succeed
, a field in traitAssertions
, returns theSucceeded
singleton:Thus placing
succeed
at the end of a test body will satisfy the type checker:An
AsyncFreeSpec
'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 with the
it
method while theAsyncFreeSpec
is in its registration phase. Any attempt to register a test after theAsyncFreeSpec
has entered its ready phase, i.e., afterrun
has been invoked on theAsyncFreeSpec
, will be met with a thrownTestRegistrationClosedException
. The recommended style of usingAsyncFreeSpec
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
.Asynchronous execution model
AsyncFreeSpec
extendsAsyncTestSuite
, which provides an implicitscala.concurrent.ExecutionContext
namedexecutionContext
. This execution context is used byAsyncFreeSpec
to transform theFuture[Assertion]
s returned by each test into theFutureOutcome
returned by thetest
function passed towithFixture
. ThisExecutionContext
is also intended to be used in the tests, including when you map assertions onto futures.On both the JVM and Scala.js, the default execution context provided by ScalaTest's asynchronous testing styles confines execution to a single thread per test. On JavaScript, where single-threaded execution is the only possibility, the default execution context is
scala.scalajs.concurrent.JSExecutionContext.Implicits.queue
. On the JVM, the default execution context is a serial execution context provided by ScalaTest itself.When ScalaTest's serial execution context is called upon to execute a task, that task is recorded in a queue for later execution. For example, one task that will be placed in this queue is the task that transforms the
Future[Assertion]
returned by an asynchronous test body to theFutureOutcome
returned from thetest
function. Other tasks that will be queued are any transformations of, or callbacks registered on,Future
s that occur in your test body, including any assertions you map ontoFuture
s. Once the test body returns, the thread that executed the test body will execute the tasks in that queue one after another, in the order they were enqueued.ScalaTest provides its serial execution context as the default on the JVM for three reasons. First, most often running both tests and suites in parallel does not give a significant performance boost compared to just running suites in parallel. Thus parallel execution of
Future
transformations within individual tests is not generally needed for performance reasons.Second, if multiple threads are operating in the same suite concurrently, you'll need to make sure access to any mutable fixture objects by multiple threads is synchronized. Although access to mutable state along the same linear chain of
Future
transformations need not be synchronized, this does not hold true for callbacks, and in general it is easy to make a mistake. Simply put: synchronizing access to shared mutable state is difficult and error prone. Because ScalaTest's default execution context on the JVM confines execution ofFuture
transformations and call backs to a single thread, you need not (by default) worry about synchronizing access to mutable state in your asynchronous-style tests.Third, asynchronous-style tests need not be complete when the test body returns, because the test body returns a
Future[Assertion]
. ThisFuture[Assertion]
will often represent a test that has not yet completed. As a result, when using a more traditional execution context backed by a thread-pool, you could potentially start many more tests executing concurrently than there are threads in the thread pool. The more concurrently execute tests you have competing for threads from the same limited thread pool, the more likely it will be that tests will intermitently fail due to timeouts.Using ScalaTest's serial execution context on the JVM will ensure the same thread that produced the
Future[Assertion]
returned from a test body is also used to execute any tasks given to the execution context while executing the test body—and that thread will not be allowed to do anything else until the test completes. If the serial execution context's task queue ever becomes empty while theFuture[Assertion]
returned by that test's body has not yet completed, the thread will block until another task for that test is enqueued. Although it may seem counter-intuitive, this blocking behavior means the total number of tests allowed to run concurrently will be limited to the total number of threads executing suites. This fact means you can tune the thread pool such that maximum performance is reached while avoiding (or at least, reducing the likelihood of) tests that fail due to timeouts because of thread competition.This thread confinement strategy does mean, however, that when you are using the default execution context on the JVM, you must be sure to never block in the test body waiting for a task to be completed by the execution context. If you block, your test will never complete. This kind of problem will be obvious, because the test will consistently hang every time you run it. (If a test is hanging, and you're not sure which one it is, enable slowpoke notifications.) If you really do want to block in your tests, you may wish to just use a traditional
FreeSpec
withScalaFutures
instead. Alternatively, you could override theexecutionContext
and use a traditionalExecutionContext
backed by a thread pool. This will enable you to block in an asynchronous-style test on the JVM, but you'll need to worry about synchronizing access to shared mutable state.To use a different execution context, just override
executionContext
. For example, if you prefer to use therunNow
execution context on Scala.js instead of the defaultqueue
, you would write:If you prefer on the JVM to use the global execution context, which is backed by a thread pool, instead of ScalaTest's default serial execution contex, which confines execution to a single thread, you would write:
Serial and parallel test execution
By default (unless you mix in
ParallelTestExecution
), tests in anAsyncFreeSpec
will be executed one after another, i.e., serially. This is true whether those tests returnAssertion
orFuture[Assertion]
, no matter what threads are involved. This default behavior allows you to re-use a shared fixture, such as an external database that needs to be cleaned after each test, in multiple tests in async-style suites. This is implemented by registering each test, other than the first test, to run as a continuation after the previous test completes.If you want the tests of an
AsyncFreeSpec
to be executed in parallel, you must mix inParallelTestExecution
and enable parallel execution of tests in your build. You enable parallel execution inRunner
with the-P
command line flag. In the ScalaTest Maven Plugin, setparallel
totrue
. Insbt
, parallel execution is the default, but to be explicit you can write:On the JVM, if both
ParallelTestExecution
is mixed in and parallel execution is enabled in the build, tests in an async-style suite will be started in parallel, using threads from theDistributor
, and allowed to complete in parallel, using threads from theexecutionContext
. If you are using ScalaTest's serial execution context, the JVM default, asynchronous tests will run in parallel very much like traditional (such asFreeSpec
) tests run in parallel: 1) BecauseParallelTestExecution
extendsOneInstancePerTest
, each test will run in its own instance of the test class, you need not worry about synchronizing access to mutable instance state shared by different tests in the same suite. 2) Because the serial execution context will confine the execution of each test to the single thread that executes the test body, you need not worry about synchronizing access to shared mutable state accessed by transformations and callbacks ofFuture
s inside the test.If
ParallelTestExecution
is mixed in but parallel execution of suites is not enabled, asynchronous tests on the JVM will be started sequentially, by the single thread that invokedrun
, but without waiting for one test to complete before the next test is started. As a result, asynchronous tests will be allowed to complete in parallel, using threads from theexecutionContext
. If you are using the serial execution context, however, you'll see the same behavior you see when parallel execution is disabled and a traditional suite that mixes inParallelTestExecution
is executed: the tests will run sequentially. If you use an execution context backed by a thread-pool, such asglobal
, however, even though tests will be started sequentially by one thread, they will be allowed to run concurrently using threads from the execution context's thread pool.The latter behavior is essentially what you'll see on Scala.js when you execute a suite that mixes in
ParallelTestExecution
. Because only one thread exists when running under JavaScript, you can't "enable parallel execution of suites." However, it may still be useful to run tests in parallel on Scala.js, because tests can invoke API calls that are truly asynchronous by calling into external APIs that take advantage of non-JavaScript threads. Thus on Scala.js,ParallelTestExecution
allows asynchronous tests to run in parallel, even though they must be started sequentially. This may give you better performance when you are using API calls in your Scala.js tests that are truly asynchronous.Futures and expected exceptions
If you need to test for expected exceptions in the context of futures, you can use the
recoverToSucceededIf
andrecoverToExceptionIf
methods of traitRecoverMethods
. Because this trait is mixed into supertraitAsyncTestSuite
, both of these methods are available by default in anAsyncFreeSpec
.If you just want to ensure that a future fails with a particular exception type, and do not need to inspect the exception further, use
recoverToSucceededIf
:The
recoverToSucceededIf
method performs a job similar toassertThrows
, except in the context of a future. It transforms aFuture
of any type into aFuture[Assertion]
that succeeds only if the original future fails with the specified exception. Here's an example in the REPL:Otherwise it fails with an error message similar to those given by
assertThrows
:The
recoverToExceptionIf
method differs from therecoverToSucceededIf
in its behavior when the assertion succeeds:recoverToSucceededIf
yields aFuture[Assertion]
, whereasrecoverToExceptionIf
yields aFuture[T]
, whereT
is the expected exception type.In other words,
recoverToExpectionIf
is tointercept
asrecovertToSucceededIf
is toassertThrows
. The first one allows you to perform further assertions on the expected exception. The second one gives you a result type that will satisfy the type checker at the end of the test body. Here's an example showingrecoverToExceptionIf
in the REPL: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,
AsyncFreeSpec
adds a methodignore
to strings that can be used instead ofin
to register a test. For example, to temporarily disable the test with the name"addSoon will eventually compute a sum of passed Ints"
, just change “in
” into “ignore
,” like this:If you run this version of
AddSpec
with:It will run only the second test and report that the first test was ignored:
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: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
AddSpec
in the above example with the@Ignore
tag annotation means that both tests in the class will be ignored. If you run the aboveAddSpec
in the Scala interpreter, you'll see: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.If you want to ignore all tests of a suite on Scala.js, where annotations can't be inspected at runtime, you'll need to change
it
toignore
at each test site. To make a suite non-discoverable on Scala.js, ensure it does not declare a public no-arg constructor. You can either declare a public constructor that takes one or more arguments, or make the no-arg constructor non-public. Because this technique will also make the suite non-discoverable on the JVM, it is a good approach for suites you want to run (but not be discoverable) on both Scala.js and the JVM.Informers
One of the parameters to
AsyncFreeSpec
'srun
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 byAsyncFreeSpec
'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.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 byAsyncFreeSpec
to pass such information to the reporter. Here's an example:If you run this
AsyncFreeSpec
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
AsyncFreeSpec
also provides amarkup
method that returns aDocumenter
, which allows you to send to theReporter
text formatted in Markdown syntax. You can pass the extra information to theDocumenter
via itsapply
method. TheDocumenter
will then pass the information to theReporter
via anMarkupProvided
event.Here's an example
AsyncFreeSpec
that usesmarkup
: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 aboveSetSpec
would look like in the HTML reporter:Notifiers and alerters
ScalaTest records text passed to
info
andmarkup
during tests, and sends the recorded text in therecordedEvents
field of test completion events likeTestSucceeded
andTestFailed
. This allows string reporters (like the standard out reporter) to showinfo
andmarkup
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 theinfo
andmarkup
text in red. If a test succeeds, string reporters will show theinfo
andmarkup
text in green. While this approach helps the readability of reports, it means that you can't useinfo
to get status updates from long running tests.To get immediate (i.e., non-recorded) notifications from tests, you can use
note
(aNotifier
) andalert
(anAlerter
). Here's an example showing the differences: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
andmarkup
for text that should form part of the specification output. Usenote
andalert
to send status notifications. (Because the HTML reporter is intended to produce a readable, printable specification,info
andmarkup
text will appear in the HTML report, butnote
andalert
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. 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, has not yet been implemented. Here's an example:(Note: "
(pending)
" is the body of the test. Thus the test contains just one statement, an invocation of thepending
method, which throwsTestPendingException
.) If you run this version ofAddSpec
with:It will run both tests, but report that first test 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 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
.Tagging tests
An
AsyncFreeSpec
's tests may be classified into groups by tagging them with string names. As with any suite, when executing anAsyncFreeSpec
, groups of tests can optionally be included and/or excluded. To tag anAsyncFreeSpec
's tests, you pass objects that extend classorg.scalatest.Tag
to methods that register tests. ClassTag
takes one parameter, a string name. If you have created tag annotation interfaces as described in theTag
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 theTag
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 forAsyncFreeSpec
s like this:Given these definitions, you could place
AsyncFreeSpec
tests into groups with tags like this:This code marks both tests with the
org.scalatest.tags.Slow
tag, and the second test 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.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 anAsyncFreeSpec
in one stroke by annotating the class. For more information and examples, see the documentation for classTag
. 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 in async styles:
withFixture
Each technique is geared towards helping you reduce code duplication without introducing instance
var
s, shared mutable objects, or other dependencies between tests. Eliminating shared mutable state across tests will make your test code easier to reason about and eliminate the need to synchronize access to shared mutable state on the JVM.The following sections describe these techniques, including explaining the recommended usage for each. But first, here's a table summarizing the options:
withFixture
when most or all tests need the same fixture.withFixture(NoArgAsyncTest)
withFixture(OneArgAsyncTest)
instead)withFixture(OneArgAsyncTest)
BeforeAndAfter
BeforeAndAfterEach
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 a 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:
If you need to configure fixture objects differently in different tests, you can pass configuration into the get-fixture method. For example, you could pass in an initial value for a fixture object as a parameter to the get-fixture method.
Overriding
withFixture(NoArgAsyncTest)
Although the get-fixture method approach takes care of setting up a fixture at the beginning of each test, it doesn'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(NoArgAsyncTest)
, a method defined in traitAsyncTestSuite
, a supertrait ofAsyncFreeSpec
.Trait
AsyncFreeSpec
'srunTest
method passes a no-arg async test function towithFixture(NoArgAsyncTest)
. It iswithFixture
's responsibility to invoke that test function. The default implementation ofwithFixture
simply invokes the function and returns the result, like this:You can, therefore, override
withFixture
to perform setup before invoking the test function, and/or perform cleanup after the test completes. The recommended way to ensure cleanup is performed after a test completes is to use thecomplete
-lastly
syntax, defined in supertraitCompleteLastly
. Thecomplete
-lastly
syntax will ensure that cleanup will occur whether future-producing code completes abruptly by throwing an exception, or returns normally yielding a future. In the latter case,complete
-lastly
will register the cleanup code to execute asynchronously when the future completes.The
withFixture
method is designed to be stacked, and to enable this, you should always call thesuper
implementation ofwithFixture
, 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:If you have no cleanup to perform, you can write
withFixture
like this instead:If you want to perform an action only for certain outcomes, you'll need to register code performing that action as a callback on the
Future
using one ofFuture
's registration methods:onComplete
,onSuccess
, oronFailure
. Note that if a test fails, that will be treated as ascala.util.Success(org.scalatest.Failed)
. So if you want to perform an action if a test fails, for example, you'd register the callback usingonSuccess
.Here's an example in which
withFixture(NoArgAsyncTest)
is used to take a snapshot of the working directory if a test fails, and send that information to the standard output stream:Running this version of
ExampleSpec
in the interpreter in a directory with two files,hello.txt
andworld.txt
would give the following output:Note that the
NoArgAsyncTest
passed towithFixture
, in addition to anapply
method that executes the test, also includes the test name and the config map passed torunTest
. Thus you can also use the test name and configuration objects in yourwithFixture
implementation.Lastly, if you want to transform the outcome in some way in
withFixture
, you'll need to use either themap
ortransform
methods ofFuture
, like this:Note that a
NoArgAsyncTest
'sapply
method will return ascala.util.Failure
only if the test completes abruptly with a "test-fatal" exception (such asOutOfMemoryError
) that should cause the suite to abort rather than the test to fail. Thus usually you would usemap
to transform future outcomes, nottransform
, so that such test-fatal exceptions pass through unchanged. The suite will abort asynchronously with any exception returned fromNoArgAsyncTest
's apply method in ascala.util.Failure
.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
.)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 databases, it is a good idea to give each 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
fixture.AsyncTestSuite
and overridingwithFixture(OneArgAsyncTest)
. Each test in afixture.AsyncTestSuite
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 aOneArgAsyncTest
. ThiswithFixture
method is responsible for invoking the one-arg async test function, so you can perform fixture set up before invoking and passing the fixture into the test function, and ensure clean up is performed after the test completes.To enable the stacking of traits that define
withFixture(NoArgAsyncTest)
, it is a good idea to letwithFixture(NoArgAsyncTest)
invoke the test function instead of invoking the test function directly. To do so, you'll need to convert theOneArgAsyncTest
to aNoArgAsyncTest
. You can do that by passing the fixture object to thetoNoArgAsyncTest
method ofOneArgAsyncTest
. In other words, instead of writing “test(theFixture)
”, you'd delegate responsibility for invoking the test function to thewithFixture(NoArgAsyncTest)
method of the same instance by writing:Here's a complete example:
In this example, the tests required one fixture object, a
StringActor
. If your tests need multiple fixture objects, you can simply define theFixtureParam
type to be a tuple containing the objects or, alternatively, a case class containing the objects. For more information on thewithFixture(OneArgAsyncTest)
technique, see the documentation forfixture.AsyncFreeSpec
.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 withbefore
and/or after each test each test withafter
, like this:Note that the only way
before
andafter
code can communicate with test code is via some side-effecting mechanism, commonly by reassigning instancevar
s or by changing the state of mutable objects held from instanceval
s (as in this example). If using instancevar
s or mutable objects held from instanceval
s 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.Note that on the JVM, if you override ScalaTest's default serial execution context, you will likely need to worry about synchronizing access to shared mutable fixture state, because the execution context may assign different threads to process different
Future
transformations. Although access to mutable state along the same linear chain ofFuture
transformations need not be synchronized, it can be difficult to spot cases where these constraints are violated. The best approach is to use only immutable objects when transformingFuture
s. When that's not practical, involve only thread-safe mutable objects, as is done in the above example. On Scala.js, by contrast, you need not worry about thread synchronization, because in effect only one thread exists.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 traitBeforeAndAfterEach
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 callsuper.withFixture
. Here's an example in which theStringBuilderActor
andStringBufferActor
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” toBuffer
. If you wantedBuffer
to be “super” toBuilder
, you need only switch the order you mix them together, like this: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.afterEach
throws an exception.The difference between stacking traits that extend
BeforeAndAfterEach
versus traits that implementwithFixture
is that setup and cleanup code happens before and after the test inBeforeAndAfterEach
, but at the beginning and end of the test inwithFixture
. Thus if awithFixture
method completes abruptly with an exception, it is considered a failed test. By contrast, if any of thebeforeEach
orafterEach
methods ofBeforeAndAfterEach
complete abruptly, it is considered an aborted 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 an
AsyncFreeSpec
, you first place shared tests in behavior functions. These behavior functions will be invoked during the construction phase of anyAsyncFreeSpec
that uses them, so that the tests they contain will be registered as tests in thatAsyncFreeSpec
. For example, given thisStackActor
class:You may want to test the stack represented by the
StackActor
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 yourAsyncFreeSpec
forStackActor
, 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
AsyncFreeSpec
that uses them. If they are shared between differentAsyncFreeSpec
s, however, you could also define them in a separate trait that is mixed into eachAsyncFreeSpec
that uses them. For example, here thenonEmptyStackActor
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
AsyncFreeSpec
offers a DSL for the purpose, which looks like this:behave like nonEmptyStackActor(almostEmptyStackActor, LastValuePushed, almostEmptyStackActorName)
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> org.scalatest.run(new StackSpec) StackSpec: A Stack (when empty) - should be empty - should complain on peek - should complain on pop (with one item) should - return non-empty StackInfo when Size is fired at non-empty stack actor: almost empty stack actor - return before and after StackInfo that has existing size and lastItemAdded as top when Peek is fired at non-empty stack actor: almost empty stack actor - return before and after StackInfo that has existing size - 1 and lastItemAdded as top when Pop is fired at non-empty stack actor: almost empty stack actor - return non-full StackInfo when Size is fired at non-full stack actor: almost empty stack actor - return before and after StackInfo that has existing size + 1 and new item as top when Push is fired at non-full stack actor: almost empty stack actor (with one item less than capacity) should - return non-empty StackInfo when Size is fired at non-empty stack actor: almost full stack actor - return before and after StackInfo that has existing size and lastItemAdded as top when Peek is fired at non-empty stack actor: almost full stack actor - return before and after StackInfo that has existing size - 1 and lastItemAdded as top when Pop is fired at non-empty stack actor: almost full stack actor - return non-full StackInfo when Size is fired at non-full stack actor: almost full stack actor - return before and after StackInfo that has existing size + 1 and new item as top when Push is fired at non-full stack actor: almost full stack actor (full) - should be full should - return non-empty StackInfo when Size is fired at non-empty stack actor: full stack actor - return before and after StackInfo that has existing size and lastItemAdded as top when Peek is fired at non-empty stack actor: full stack actor - return before and after StackInfo that has existing size - 1 and lastItemAdded as top when Pop is fired at non-empty stack actor: full stack actor - 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. Although in an
AsyncFreeSpec
, the-
clause is a nesting construct analogous toAsyncFunSpec
'sdescribe
clause, you many sometimes need to do a bit of extra work to ensure that the test names are unique. If a duplicate test name problem shows up in anAsyncFreeSpec
, you'll need to pass in a prefix or suffix string to add to each test name. You can calltoString
on the shared fixture object, or pass this string the same way you pass any other data needed by the shared tests. This is the approach taken by the previousAsyncFreeSpecStackBehaviors
example.Given this
AsyncFreeSpecStackBehaviors
trait, calling it with thealmostEmptyStackActor
fixture, like this:behave like nonEmptyStackActor(almostEmptyStackActor, LastValuePushed, almostEmptyStackActorName)
yields test names:
A Stack (when non-empty) should return non-empty StackInfo when Size is fired at non-empty stack actor: almost empty stack actor
A Stack (when non-empty) should return before and after StackInfo that has existing size and lastItemAdded as top when Peek is fired at non-empty stack actor: almost empty stack actor
A Stack (when non-empty) should return before and after StackInfo that has existing size - 1 and lastItemAdded as top when Pop is fired at non-empty stack actor: almost empty stack actor
Whereas calling it with the
almostFullStackActor
fixture, like this:behave like nonEmptyStackActor(almostFullStackActor, LastValuePushed, almostFullStackActorName)
yields different test names:
A Stack (when non-empty) should return non-empty StackInfo when Size is fired at non-empty stack actor: almost full stack actor
A Stack (when non-empty) should return before and after StackInfo that has existing size and lastItemAdded as top when Peek is fired at non-empty stack actor: almost full stack actor
A Stack (when non-empty) should return before and after StackInfo that has existing size - 1 and lastItemAdded as top when Pop is fired at non-empty stack actor: almost full stack actor