Trait that contains ScalaTest's basic assertion methods, suitable for use with JUnit.
The assertion methods provided in this trait look and behave exactly like the ones in
Assertions
, except instead of throwing
TestFailedException
they throw
JUnitTestFailedError
,
which extends junit.framework.AssertionFailedError
.
JUnit 3 (release 3.8 and earlier) distinguishes between failures and errors.
If a test fails because of a failed assertion, that is considered a failure. If a test
fails for any other reason, either the test code or the application being tested threw an unexpected
exception, that is considered an error. The way JUnit 3 decides whether an exception represents
a failure or error is that only thrown junit.framework.AssertionFailedError
s are considered
failures. Any other exception type is considered an error. The exception type thrown by the JUnit 3
assertion methods declared in junit.framework.Assert
(such as assertEquals
,
assertTrue
, and fail
) is, therefore, AssertionFailedError
.
In JUnit 4, AssertionFailedError
was made to extend java.lang.AssertionError
,
and the distinction between failures and errors was essentially dropped. However, some tools that integrate
with JUnit carry on this distinction, so even if you are using JUnit 4 you may want to use this
AssertionsForJUnit
trait instead of plain-old ScalaTest
Assertions
.
To use this trait in a JUnit 3 TestCase
, you can mix it into your TestCase
class, like this:
import junit.framework.TestCase import org.scalatest.junit.AssertionsForJUnitclass MyTestCase extends TestCase with AssertionsForJUnit {
def testSomething() { assert("hi".charAt(1) === 'i') }
// ... }
You can alternatively import the methods defined in this trait.
import junit.framework.TestCase import org.scalatest.junit.AssertionsForJUnit._class MyTestCase extends TestCase {
def testSomething() { assert("hi".charAt(1) === 'i') }
// ... }
For details on the importing approach, see the documentation
for the AssertionsForJUnit
companion object.
For the details on the AssertionsForJUnit
syntax, see the Scaladoc documentation for
org.scalatest.Assertions
Class used via an implicit conversion to enable any two objects to be compared with
===
in assertions in tests.
o != arg0
is the same as !(o == (arg0))
.
o != arg0
is the same as !(o == (arg0))
.
the object to compare against this object for dis-equality.
false
if the receiver object is equivalent to the argument; true
otherwise.
o == arg0
is the same as if (o eq null) arg0 eq null else o.equals(arg0)
.
o == arg0
is the same as if (o eq null) arg0 eq null else o.equals(arg0)
.
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
o == arg0
is the same as o.equals(arg0)
.
o == arg0
is the same as o.equals(arg0)
.
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
This method is used to cast the receiver object to be of type T0
.
This method is used to cast the receiver object to be of type T0
.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression
1.asInstanceOf[String]
will throw a ClassCastException
at runtime, while the expression
List(1).asInstanceOf[List[String]]
will not. In the latter example, because the type argument is erased as
part of compilation it is not possible to check whether the contents of the list are of the requested typed.
the receiver object.
Assert that an Option[String]
is None
.
Assert that an Option[String]
is None
.
If the condition is None
, this method returns normally.
Else, it throws TestFailedException
with the String
value of the Some
included in the TestFailedException
's
detail message.
This form of assert
is usually called in conjunction with an
implicit conversion to Equalizer
, using a ===
comparison, as in:
assert(a === b)
For more information on how this mechanism works, see the documentation for
Equalizer
.
the Option[String]
to assert
Assert that an Option[String]
is None
.
Assert that an Option[String]
is None
.
If the condition is None
, this method returns normally.
Else, it throws TestFailedException
with the String
value of the Some
, as well as the
String
obtained by invoking toString
on the
specified message
,
included in the TestFailedException
's detail message.
This form of assert
is usually called in conjunction with an
implicit conversion to Equalizer
, using a ===
comparison, as in:
assert(a === b, "extra info reported if assertion fails")
For more information on how this mechanism works, see the documentation for
Equalizer
.
the Option[String]
to assert
An objects whose toString
method returns a message to include in a failure report.
Assert that a boolean condition, described in String
message
, is true.
Assert that a boolean condition, described in String
message
, is true.
If the condition is true
, this method returns normally.
Else, it throws TestFailedException
with the
String
obtained by invoking toString
on the
specified message
as the exception's detail message.
the boolean condition to assert
An objects whose toString
method returns a message to include in a failure report.
Assert that a boolean condition is true.
Assert that a boolean condition is true.
If the condition is true
, this method returns normally.
Else, it throws TestFailedException
.
the boolean condition to assert
This method creates and returns a copy of the receiver object.
This method creates and returns a copy of the receiver object.
The default implementation of the clone
method is platform dependent.
a copy of the receiver object.
Implicit conversion from Any
to Equalizer
, used to enable
assertions with ===
comparisons.
Implicit conversion from Any
to Equalizer
, used to enable
assertions with ===
comparisons.
For more information on this mechanism, see the documentation for </code>Equalizer</code>.
Because trait Suite
mixes in Assertions
, this implicit conversion will always be
available by default in ScalaTest Suite
s. This is the only implicit conversion that is in scope by default in every
ScalaTest Suite
. Other implicit conversions offered by ScalaTest, such as those that support the matchers DSL
or invokePrivate
, must be explicitly invited into your test code, either by mixing in a trait or importing the
members of its companion object. The reason ScalaTest requires you to invite in implicit conversions (with the exception of the
implicit conversion for ===
operator) is because if one of ScalaTest's implicit conversions clashes with an
implicit conversion used in the code you are trying to test, your program won't compile. Thus there is a chance that if you
are ever trying to use a library or test some code that also offers an implicit conversion involving a ===
operator,
you could run into the problem of a compiler error due to an ambiguous implicit conversion. If that happens, you can turn off
the implicit conversion offered by this convertToEqualizer
method simply by overriding the method in your
Suite
subclass, but not marking it as implicit:
// In your Suite subclass override def convertToEqualizer(left: Any) = new Equalizer(left)
the object whose type to convert to Equalizer
.
This method is used to test whether the argument (arg0
) is a reference to the
receiver object (this
).
This method is used to test whether the argument (arg0
) is a reference to the
receiver object (this
).
The eq
method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on
non-null instances of AnyRef
:
* It is reflexive: for any non-null instance x
of type AnyRef
, x.eq(x)
returns true
.
* It is symmetric: for any non-null instances x
and y
of type AnyRef
, x.eq(y)
returns true
if and
only if y.eq(x)
returns true
.
* It is transitive: for any non-null instances x
, y
, and z
of type AnyRef
if x.eq(y)
returns true
and y.eq(z)
returns true
, then x.eq(z)
returns true
.
Additionally, the eq
method has three other properties.
* It is consistent: for any non-null instances x
and y
of type AnyRef
, multiple invocations of
x.eq(y)
consistently returns true
or consistently returns false
.
* For any non-null instance x
of type AnyRef
, x.eq(null)
and null.eq(x)
returns false
.
* null.eq(null)
returns true
.
When overriding the equals
or hashCode
methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they
should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).
the object to compare against this object for reference equality.
true
if the argument is a reference to the receiver object; false
otherwise.
This method is used to compare the receiver object (this
) with the argument object (arg0
) for equivalence.
This method is used to compare the receiver object (this
) with the argument object (arg0
) for equivalence.
The default implementations of this method is an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence
relation]:
* It is reflexive: for any instance x
of type Any
, x.equals(x)
should return true
.
* It is symmetric: for any instances x
and y
of type Any
, x.equals(y)
should return true
if and
only if y.equals(x)
returns true
.
* It is transitive: for any instances x
, y
, and z
of type AnyRef
if x.equals(y)
returns true
and
y.equals(z)
returns true
, then x.equals(z)
should return true
.
If you override this method, you should verify that your implementation remains an equivalence relation.
Additionally, when overriding this method it is often necessary to override hashCode
to ensure that objects
that are "equal" (o1.equals(o2)
returns true
) hash to the same scala.Int
(o1.hashCode.equals(o2.hashCode)
).
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
Expect that the value passed as expected
equals the value passed as actual
.
Expect that the value passed as expected
equals the value passed as actual
.
If the actual
value equals the expected
value
(as determined by ==
), expect
returns
normally. Else, expect
throws an
TestFailedException
whose detail message includes the expected and actual values.
the expected value
the actual value, which should equal the passed expected
value
Expect that the value passed as expected
equals the value passed as actual
.
Expect that the value passed as expected
equals the value passed as actual
.
If the actual
equals the expected
(as determined by ==
), expect
returns
normally. Else, if actual
is not equal to expected
, expect
throws an
TestFailedException
whose detail message includes the expected and actual values, as well as the String
obtained by invoking toString
on the passed message
.
the expected value
An object whose toString
method returns a message to include in a failure report.
the actual value, which should equal the passed expected
value
Throws TestFailedException
, with the passed
Throwable
cause, to indicate a test failed.
Throws TestFailedException
, with the passed
Throwable
cause, to indicate a test failed.
The getMessage
method of the thrown TestFailedException
will return cause.toString()
.
a Throwable
that indicates the cause of the failure.
Throws TestFailedException
, with the passed
String
message
as the exception's detail
message and Throwable
cause, to indicate a test failed.
Throws TestFailedException
, with the passed
String
message
as the exception's detail
message and Throwable
cause, to indicate a test failed.
A message describing the failure.
A Throwable
that indicates the cause of the failure.
Throws TestFailedException
, with the passed
String
message
as the exception's detail
message, to indicate a test failed.
Throws TestFailedException
, with the passed
String
message
as the exception's detail
message, to indicate a test failed.
A message describing the failure.
Throws TestFailedException
to indicate a test failed.
Throws TestFailedException
to indicate a test failed.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
The details of when and if the finalize
method are invoked, as well as the interaction between finalize
and non-local returns and exceptions, are all platform dependent.
Returns a representation that corresponds to the dynamic class of the receiver object.
Returns a representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
Returns a hash code value for the object.
Returns a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)
) yet
not be equal (o1.equals(o2)
returns false
). A degenerate implementation could always return 0
.
However, it is required that if two objects are equal (o1.equals(o2)
returns true
) that they have
identical hash codes (o1.hashCode.equals(o2.hashCode)
). Therefore, when overriding this method, be sure
to verify that the behavior is consistent with the equals
method.
the hash code value for the object.
Intercept and return an exception that's expected to be thrown by the passed function value.
Intercept and return an exception that's expected to
be thrown by the passed function value. The thrown exception must be an instance of the
type specified by the type parameter of this method. This method invokes the passed
function. If the function throws an exception that's an instance of the specified type,
this method returns that exception. Else, whether the passed function returns normally
or completes abruptly with a different exception, this method throws TestFailedException
.
Note that the type specified as this method's type parameter may represent any subtype of
AnyRef
, not just Throwable
or one of its subclasses. In
Scala, exceptions can be caught based on traits they implement, so it may at times make sense
to specify a trait that the intercepted exception's class must mix in. If a class instance is
passed for a type that could not possibly be used to catch an exception (such as String
,
for example), this method will complete abruptly with a TestFailedException
.
the function value that should throw the expected exception
an implicit Manifest
representing the type of the specified
type parameter.
the intercepted exception, if it is of the expected type
This method is used to test whether the dynamic type of the receiver object is T0
.
This method is used to test whether the dynamic type of the receiver object is T0
.
Note that the test result of the test is modulo Scala's erasure semantics. Therefore the expression
1.isInstanceOf[String]
will return false
, while the expression List(1).isInstanceOf[List[String]]
will
return true
. In the latter example, because the type argument is erased as part of compilation it is not
possible to check whether the contents of the list are of the requested typed.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
o.ne(arg0)
is the same as !(o.eq(arg0))
.
o.ne(arg0)
is the same as !(o.eq(arg0))
.
the object to compare against this object for reference dis-equality.
false
if the argument is not a reference to the receiver object; true
otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Returns a string representation of the object.
Returns a string representation of the object.
The default representation is platform dependent.
a string representation of the object.
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
Trait that contains ScalaTest's basic assertion methods, suitable for use with JUnit.
The assertion methods provided in this trait look and behave exactly like the ones in
Assertions
, except instead of throwingTestFailedException
they throwJUnitTestFailedError
, which extendsjunit.framework.AssertionFailedError
.JUnit 3 (release 3.8 and earlier) distinguishes between failures and errors. If a test fails because of a failed assertion, that is considered a failure. If a test fails for any other reason, either the test code or the application being tested threw an unexpected exception, that is considered an error. The way JUnit 3 decides whether an exception represents a failure or error is that only thrown
junit.framework.AssertionFailedError
s are considered failures. Any other exception type is considered an error. The exception type thrown by the JUnit 3 assertion methods declared injunit.framework.Assert
(such asassertEquals
,assertTrue
, andfail
) is, therefore,AssertionFailedError
.In JUnit 4,
AssertionFailedError
was made to extendjava.lang.AssertionError
, and the distinction between failures and errors was essentially dropped. However, some tools that integrate with JUnit carry on this distinction, so even if you are using JUnit 4 you may want to use thisAssertionsForJUnit
trait instead of plain-old ScalaTestAssertions
.To use this trait in a JUnit 3
TestCase
, you can mix it into yourTestCase
class, like this:You can alternatively import the methods defined in this trait.
For details on the importing approach, see the documentation for the
AssertionsForJUnit
companion object. For the details on theAssertionsForJUnit
syntax, see the Scaladoc documentation fororg.scalatest.Assertions