Helper class used by code generated by the assert
macro.
Helper class used by code generated by the assert
macro.
A test function taking no arguments and returning an Outcome
.
A test function taking no arguments and returning an Outcome
.
For more detail and examples, see the relevant section in the
documentation for trait fixture.FlatSpec
.
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.
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
.
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.
Executes this Suite
, printing results to the standard output.
Executes this Suite
, printing results to the standard output.
This method, which simply invokes the other overloaded form of execute
with default parameter values,
is intended for use only as a mini-DSL for the Scala interpreter. It allows you to execute a Suite
in the
interpreter with a minimum of finger typing:
scala> new SetSpec execute An empty Set - should have size 0 - should produce NoSuchElementException when head is invoked !!! IGNORED !!!
If you do ever want to invoke execute
outside the Scala interpreter, it is best style to invoke it with
empty parens to indicate it has a side effect, like this:
// Use empty parens form in regular code (outside the Scala interpreter) (new ExampleSuite).execute()
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.
Intercept and return an exception that's expected to be thrown by the passed function value.
Intercept and return an exception that's expected to
be thrown by the passed function value. The thrown exception must be an instance of the
type specified by the type parameter of this method. This method invokes the passed
function. If the function throws an exception that's an instance of the specified type,
this method returns that exception. Else, whether the passed function returns normally
or completes abruptly with a different exception, this method throws TestFailedException
.
Note that the type specified as this method's type parameter may represent any subtype of
AnyRef
, not just Throwable
or one of its subclasses. In
Scala, exceptions can be caught based on traits they implement, so it may at times make sense
to specify a trait that the intercepted exception's class must mix in. If a class instance is
passed for a type that could not possibly be used to catch an exception (such as String
,
for example), this method will complete abruptly with a TestFailedException
.
the function value that should throw the expected exception
an implicit 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
passed expected
value.
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
.
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
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.
Execute this TestNGSuite
.
Execute this TestNGSuite
.
an optional name of one test to execute. If None
, this class will execute all relevant tests.
I.e., None
acts like a wildcard that means execute all relevant tests in this TestNGSuite
.
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.
Throws UnsupportedOperationException
, because this method is unused by this
trait, given this trait's run
method delegates to TestNG to run
its tests.
Throws UnsupportedOperationException
, because this method is unused by this
trait, given this trait's run
method delegates to TestNG to run
its tests.
The main purpose of this method implementation is to render a compiler error an attempt
to mix in a trait that overrides runNestedSuites
. Because this
trait does not actually use runNestedSuites
, the attempt to mix
in behavior would very likely not work.
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.
UnsupportedOperationException
always.
Throws UnsupportedOperationException
, because this method is unused by this
trait, given this trait's run
method delegates to TestNG to run
its tests.
Throws UnsupportedOperationException
, because this method is unused by this
trait, given this trait's run
method delegates to TestNG to run
its tests.
The main purpose of this method implementation is to render a compiler error an attempt
to mix in a trait that overrides runTest
. Because this
trait does not actually use runTest
, the attempt to mix
in behavior would very likely not work.
the name of one test to run.
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 .
UnsupportedOperationException
always.
Throws UnsupportedOperationException
, because this method is unused by this
trait, given this trait's run
method delegates to TestNG to run
its tests.
Throws UnsupportedOperationException
, because this method is unused by this
trait, given this trait's run
method delegates to TestNG to run
its tests.
The main purpose of this method implementation is to render a compiler error an attempt
to mix in a trait that overrides runTests
. Because this
trait does not actually use runTests
, the attempt to mix
in behavior would very likely not work.
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 started by this method have completed, and whether or not a failure occurred.
UnsupportedOperationException
always.
Suite style name.
Suite style name.
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 tests that are tagged and
whose associated values are the Set
of tag names for the test.
A Map
whose keys are String
names of tests that are tagged and
whose associated values are the Set
of tag names for the test. If a test has no associated tags, its name
does not appear as a key in the returned Map
. If this Suite
contains no tests with tags, this
method returns an empty Map
.
This trait's implementation of this method uses Java reflection to discover any Java annotations attached to its test methods. The
fully qualified name of each unique annotation that extends TagAnnotation
is considered a tag. This trait's
implementation of this method, therefore, places one key/value pair into to the
Map
for each test for which a tag annotation is discovered through reflection.
In addition to test methods annotations, this trait's implementation will also auto-tag test methods with class level annotations. For example, if you annotate @Ignore at the class level, all test methods in the class will be auto-annotated with @Ignore.
Subclasses may override this method to define and/or discover tags in a custom manner, but overriding method implementations
should never return an empty Set
as a value. If a test has no tags, its name should not appear as a key in the
returned Map
.
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
A Set
of test names.
A Set
of test names. If this Suite
contains no tests, this method returns an empty Set
.
This trait's implementation of this method returns an empty Set
.
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.
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
Throws UnsupportedOperationException
, because this method is unused by this
class, given this class's run
method delegates to JUnit to run
its tests.
Throws UnsupportedOperationException
, because this method is unused by this
class, given this class's run
method delegates to JUnit to run
its tests.
The main purpose of this method implementation is to render a compiler error an attempt
to mix in a trait that overrides withFixture
. Because this
trait does not actually use withFixture
, the attempt to mix
in behavior would very likely not work.
the no-arg test function to run with a fixture
Implementation trait for class
TestNGSuite
, which represents a suite of tests that can be run with either TestNG or ScalaTest.TestNGSuite
is a class, not a trait, to minimize compile time given there is a slight compiler overhead to mixing in traits compared to extending classes. If you need to mix the behavior ofTestNGSuite
into some other class, you can use this trait instead, because classTestNGSuite
does nothing more than extend this trait.See the documentation of the class for a detailed overview of
TestNGSuite
.