Trait that provides a domain specific language (DSL) for expressing assertions in tests
using the word should. (If you prefer the word must, you can alternatively
mix in trait MustMatchers.) For example, if you mix ShouldMatchers into
a suite class, you can write an equality assertion in that suite like this:
object should equal (3)
Here object is a variable, and can be of any type. If the object is an
Int with the value 3, execution will continue (i.e., the expression will result
in the unit value, ()). Otherwise, a TestFailedException
will be thrown with a detail message that explains the problem, such as "7 did not equal 3".
This TestFailedException will cause the test to fail.
The left should equal (right) syntax works by calling == on the left
value, passing in the right value, on every type except arrays. If left is an array, deepEquals
will be invoked on left, passing in right. Thus, even though this expression
will yield false, because Array's equals method compares object identity:
Array(1, 2) == Array(1, 2) // yields false
The following expression will not result in a TestFailedException, because deepEquals compares
the two arrays structurally, taking into consideration the equality of the array's contents:
Array(1, 2) should equal (Array(1, 2)) // succeeds (i.e., does not throw TestFailedException)
If you ever do want to verify that two arrays are actually the same object (have the same identity), you can use the
be theSameInstanceAs syntax, described below.
You can check the size or length of just about any type of object for which it would make sense. Here's how checking for length looks:
object should have length (3)
Size is similar:
object should have size (10)
The length syntax can be used with any object that has a field or method named length
or a method named getLength. Similarly, the size syntax can be used with any
object that has a field or method named size or a method named getSize.
The type of a length or size field, or return type of a method, must be either Int
or Long. Any such method must take no parameters. (The Scala compiler will ensure at compile time that
the object on which should is being invoked has the appropriate structure.)
You can check for whether a string starts with, ends with, or includes a substring like this:
string should startWith ("Hello")
string should endWith ("world")
string should include ("seven")
You can check for whether a string starts with, ends with, or includes a regular expression, like this:
string should startWith regex ("Hel*o")
string should endWith regex ("wo.ld")
string should include regex ("wo.ld")
And you can check whether a string fully matches a regular expression, like this:
string should fullyMatch regex ("""(-)?(\d+)(\.\d*)?""")
The regular expression passed following the regex token can be either a String
or a scala.util.matching.Regex.
You can check whether any type that is, or can be implicitly converted to,
an Ordered[T] is greater than, less than, greater than or equal, or less
than or equal to a value of type T. The syntax is:
one should be < (7) one should be > (0) one should be <= (7) one should be >= (0)
be === An alternate way to check for equality of two objects is to use be with
===. Here's an example:
object should be === (3)
Here object is a variable, and can be of any type. If the object is an
Int with the value 3, execution will continue (i.e., the expression will result
in the unit value, ()). Otherwise, a TestFailedException
will be thrown with a detail message that explains the problem, such as "7 was not equal to 3".
This TestFailedException will cause the test to fail.
The left should be === (right) syntax works by calling == on the left
value, passing in the right value, on every type except arrays. If left is an array, deepEquals
will be invoked on left, passing in right. Thus, even though this expression
will yield false, because Array's equals method compares object identity:
Array(1, 2) == Array(1, 2) // yields false
The following expression will not result in a TestFailedException, because deepEquals compares
the two arrays structurally, taking into consideration the equality of the array's contents:
Array(1, 2) should be === (Array(1, 2)) // succeeds (i.e., does not throw TestFailedException)
If you ever do want to verify that two arrays are actually the same object (have the same identity), you can use the
be theSameInstanceAs syntax, described below.
Boolean properties with be If an object has a method that takes no parameters and returns boolean, you can check
it by placing a Symbol (after be) that specifies the name
of the method (excluding an optional prefix of "is"). A symbol literal
in Scala begins with a tick mark and ends at the first non-identifier character. Thus,
'empty results in a Symbol object at runtime, as does
'defined and 'file. Here's an example:
emptySet should be ('empty)
Given this code, ScalaTest will use reflection to look on the object referenced from
emptySet for a method that takes no parameters and results in Boolean,
with either the name empty or isEmpty. If found, it will invoke
that method. If the method returns true, execution will continue. But if it returns
false, a TestFailedException will be thrown that will contain a detail message, such as:
Set(1, 2, 3) was not empty
This be syntax can be used with any type. If the object does
not have an appropriately named predicate method, you'll get a TestFailedException
at runtime with a detail message that explains the problem.
(For the details on how a field or method is selected during this
process, see the documentation for BeWord.)
If you think it reads better, you can optionally put a or an after
be. For example, java.io.File has two predicate methods,
isFile and isDirectory. Thus with a File object
named temp, you could write:
temp should be a ('file)
Or, given java.awt.event.KeyEvent has a method isActionKey that takes
no arguments and returns Boolean, you could assert that a KeyEvent is
an action key with:
keyEvent should be an ('actionKey)
If you prefer to check Boolean properties in a type-safe manner, you can use a BePropertyMatcher.
This would allow you to write expressions such as:
emptySet should be (empty) temp should be a (file) keyEvent should be an (actionKey)
These expressions would fail to compile if should is used on an inappropriate type, as determined
by the type parameter of the BePropertyMatcher being used. (For example, file in this example
would likely be of type BePropertyMatcher[java.io.File]. If used with an appropriate type, such an expression will compile
and at run time the Boolean property method or field will be accessed directly; i.e., no reflection will be used.
See the documentation for BePropertyMatcher for more information.
BeMatchers If you want to create a new way of using be, which doesn't map to an actual property on the
type you care about, you can create a BeMatcher. You could use this, for example, to create BeMatcher[Int]
called odd, which would match any odd Int, and even, which would match
any even Int.
Given this pair of BeMatchers, you could check whether an Int was odd or even with expressions like:
num should be (odd) num should not be (even)
For more information, see the documentation for BeMatcher.
If you need to check that two references refer to the exact same object, you can write:
ref1 should be theSameInstanceAs (ref2)
To check whether a floating point number has a value that exactly matches another, you
can use should equal:
sevenDotOh should equal (7.0)
Often, however, you may want to check whether a floating point number is within a
range. You can do that using be and plusOrMinus, like this:
sevenDotOh should be (6.9 plusOrMinus 0.2)
This expression will cause a TestFailedException to be thrown if the floating point
value, sevenDotOh is outside the range 6.7 to 7.1.
You can also use plusOrMinus with integral types, for example:
seven should be (6 plusOrMinus 2)
You can use some of the syntax shown previously with Iterable and its
subtypes. For example, you can check whether an Iterable is empty,
like this:
iterable should be ('empty)
You can check the length of an Seq (Array, List, etc.),
like this:
array should have length (3) list should have length (9)
You can check the size of any Traversable, like this:
map should have size (20) set should have size (90)
In addition, you can check whether an Iterable contains a particular
element, like this:
iterable should contain ("five")
You can also check whether a Map contains a particular key, or value, like this:
map should contain key (1)
map should contain value ("Howdy")
You can use similar syntax on Java collections (java.util.Collection) and maps (java.util.Map).
For example, you can check whether a Java Collection or Map is empty,
like this:
javaCollection should be ('empty)
javaMap should be ('empty)
Even though Java's List type doesn't actually have a length or getLength method,
you can nevertheless check the length of a Java List (java.util.List) like this:
javaList should have length (9)
You can check the size of any Java Collection or Map, like this:
javaMap should have size (20) javaSet should have size (90)
In addition, you can check whether a Java Collection contains a particular
element, like this:
javaCollection should contain ("five")
One difference to note between the syntax supported on Java collections and that of Scala
iterables is that you can't use contain (...) syntax with a Java Map.
Java differs from Scala in that its Map is not a subtype of its Collection type.
If you want to check that a Java Map contains a specific key/value pair, the best approach is
to invoke entrySet on the Java Map and check that entry set for the appropriate
element (a java.util.Map.Entry) using contain (...).
Despite this difference, the other (more commonly used) map matcher syntax works just fine on Java Maps.
You can, for example, check whether a Java Map contains a particular key, or value, like this:
javaMap should contain key (1)
javaMap should contain value ("Howdy")
All uses of be other than those shown previously perform an equality comparison. In other words, they work
the same as equals. This redundance between be and equals exists because it enables syntax
that sometimes sounds more natural. For example, instead of writing:
result should equal (null)
You can write:
result should be (null)
(Hopefully you won't write that too much given null is error prone, and Option
is usually a better, well, option.)
Here are some other examples of be used for equality comparison:
sum should be (7.0) boring should be (false) fun should be (true) list should be (Nil) option should be (None) option should be (Some(1))
As with equal, using be on arrays results in deepEquals being called, not equals. As a result,
the following expression would not throw a TestFailedException:
Array(1, 2) should be (Array(1, 2)) // succeeds (i.e., does not throw TestFailedException)
Because be is used in several ways in ScalaTest matcher syntax, just as it is used in many ways in English, one
potential point of confusion in the event of a failure is determining whether be was being used as an equality comparison or
in some other way, such as a property assertion. To make it more obvious when be is being used for equality, the failure
messages generated for those equality checks will include the word equal in them. For example, if this expression fails with a
TestFailedException:
option should be (Some(1))
The detail message in that TestFailedException will include the words "equal to" to signify be
was in this case being used for equality comparison:
Some(2) was not equal to Some(1)
If you wish to check the opposite of some condition, you can simply insert not in the expression.
Here are a few examples:
object should not be (null)
sum should not be <= (10)
mylist should not equal (yourList)
string should not startWith ("Hello")
and and or You can also combine matcher expressions with and and/or or, however,
you must place parentheses or curly braces around the and or or expression. For example,
this and-expression would not compile, because the parentheses are missing:
map should contain key ("two") and not contain value (7) // ERROR, parentheses missing!
Instead, you need to write:
map should (contain key ("two") and not contain value (7))
Here are some more examples:
number should (be > (0) and be <= (10))
option should (equal (Some(List(1, 2, 3))) or be (None))
string should (
equal ("fee") or
equal ("fie") or
equal ("foe") or
equal ("fum")
)
Two differences exist between expressions composed of these and and or operators and the expressions you can write
on regular Booleans using its && and || operators. First, expressions with and
and or do not short-circuit. The following contrived expression, for example, would print "hello, world!":
"yellow" should (equal ("blue") and equal { println("hello, world!"); "green" })
In other words, the entire and or or expression is always evaluated, so you'll see any side effects
of the right-hand side even if evaluating
only the left-hand side is enough to determine the ultimate result of the larger expression. Failure messages produced by these
expressions will "short-circuit," however,
mentioning only the left-hand side if that's enough to determine the result of the entire expression. This "short-circuiting" behavior
of failure messages is intended
to make it easier and quicker for you to ascertain which part of the expression caused the failure. The failure message for the previous
expression, for example, would be:
"yellow" did not equal "blue"
Most likely this lack of short-circuiting would rarely be noticeable, because evaluating the right hand side will usually not
involve a side effect. One situation where it might show up, however, is if you attempt to and a null check on a variable with an expression
that uses the variable, like this:
map should (not be (null) and contain key ("ouch"))
If map is null, the test will indeed fail, but with a NullPointerException, not a
TestFailedException. Here, the NullPointerException is the visible right-hand side effect. To get a
TestFailedException, you would need to check each assertion separately:
map should not be (null)
map should contain key ("ouch")
If map is null in this case, the null check in the first expression will fail with
a TestFailedException, and the second expression will never be executed.
The other difference with Boolean operators is that although && has a higher precedence than ||,
and and or
have the same precedence. Thus although the Boolean expression (a || b && c) will evaluate the && expression
before the || expression, like (a || (b && c)), the following expression:
traversable should (contain (7) or contain (8) and have size (9))
Will evaluate left to right, as:
traversable should ((contain (7) or contain (8)) and have size (9))
If you really want the and part to be evaluated first, you'll need to put in parentheses, like this:
traversable should (contain (7) or (contain (8) and have size (9)))
Options ScalaTest matchers has no special support for Options, but you can
work with them quite easily using syntax shown previously. For example, if you wish to check
whether an option is None, you can write any of:
option should equal (None)
option should be (None)
option should not be ('defined)
option should be ('empty)
If you wish to check an option is defined, and holds a specific value, you can write either of:
option should equal (Some("hi"))
option should be (Some("hi"))
If you only wish to check that an option is defined, but don't care what it's value is, you can write:
option should be ('defined)
have Using have, you can check properties of any type, where a property is an attribute of any
object that can be retrieved either by a public field, method, or JavaBean-style get
or is method, like this:
book should have (
'title ("Programming in Scala"),
'author (List("Odersky", "Spoon", "Venners")),
'pubYear (2008)
)
This expression will use reflection to ensure the title, author, and pubYear properties of object book
are equal to the specified values. For example, it will ensure that book has either a public Java field or method
named title, or a public method named getTitle, that when invoked (or accessed in the field case) results
in a the string "Programming in Scala". If all specified properties exist and have their expected values, respectively,
execution will continue. If one or more of the properties either does not exist, or exists but results in an unexpected value,
a TestFailedException will be thrown that explains the problem. (For the details on how a field or method is selected during this
process, see the documentation for HavePropertyMatcherGenerator.)
When you use this syntax, you must place one or more property values in parentheses after have, seperated by commas, where a property
value is a symbol indicating the name of the property followed by the expected value in parentheses. The only exceptions to this rule is the syntax
for checking size and length shown previously, which does not require parentheses. If you forget and put parentheses in, however, everything will
still work as you'd expect. Thus instead of writing:
array should have length (3) set should have size (90)
You can alternatively, write:
array should have (length (3)) set should have (size (90))
If a property has a value different from the specified expected value, a TestFailedError will be thrown
with a detail message that explains the problem. For example, if you assert the following on
a book whose title is Moby Dick:
book should have ('title ("A Tale of Two Cities"))
You'll get a TestFailedException with this detail message:
The title property had value "Moby Dick", instead of its expected value "A Tale of Two Cities",
on object Book("Moby Dick", "Melville", 1851)
If you prefer to check properties in a type-safe manner, you can use a HavePropertyMatcher.
This would allow you to write expressions such as:
book should have (
title ("Programming in Scala"),
author (List("Odersky", "Spoon", "Venners")),
pubYear (2008)
)
These expressions would fail to compile if should is used on an inappropriate type, as determined
by the type parameter of the HavePropertyMatcher being used. (For example, title in this example
might be of type HavePropertyMatcher[org.publiclibrary.Book]. If used with an appropriate type, such an expression will compile
and at run time the property method or field will be accessed directly; i.e., no reflection will be used.
See the documentation for HavePropertyMatcher for more information.
If none of the built-in matcher syntax (or options shown so far for extending the syntax) satisfy a particular need you have, you can create
custom Matchers that allow
you to place your own syntax directly after should. For example, class java.io.File has a method exists, which
indicates whether a file of a certain path and name exists. Because the exists method takes no parameters and returns Boolean,
you can call it using be with a symbol or BePropertyMatcher, yielding assertions like:
file should be ('exists) // using a symbol
file should be (inExistance) // using a BePropertyMatcher
Although these expressions will achieve your goal of throwing a TestFailedException if the file does not exist, they don't produce
the most readable code because the English is either incorrect or awkward. In this case, you might want to create a
custom Matcher[java.io.File]
named exist, which you could then use to write expressions like:
// using a plain-old Matcher
file should exist
file should not (exist)
file should (exist and have ('name ("temp.txt")))
Note that when you use custom Matchers, you will need to put parentheses around the custom matcher in more cases than with
the built-in syntax. For example you will often need the parentheses after not, as shown above. (There's no penalty for
always surrounding custom matchers with parentheses, and if you ever leave them off when they are needed, you'll get a compiler error.)
For more information about how to create custom Matchers, please see the documentation for the Matcher trait.
Sometimes you need to test whether a method throws an expected exception under certain circumstances, such
as when invalid arguments are passed to the method. With ShouldMatchers mixed in, you can
check for an expected exception like this:
evaluating { s.charAt(-1) } should produce [IndexOutOfBoundsException]
If charAt throws an instance of StringIndexOutOfBoundsException,
this expression will result in that exception. But if charAt completes normally, or throws a different
exception, this expression will complete abruptly with a TestFailedException.
This expression returns the caught exception so that you can inspect it further if you wish, for
example, to ensure that data contained inside the exception has the expected values. Here's an
example:
val thrown = evaluating { s.charAt(-1) } should produce [IndexOutOfBoundsException]
thrown.getMessage should equal ("String index out of range: -1")
Perhaps the most tricky part of writing assertions using ScalaTest matchers is remembering when you need or don't need parentheses, but bearing in mind a few simple rules should help. It is also reassuring to know that if you ever leave off a set of parentheses when they are required, your code will not compile. Thus the compiler will help you remember when you need the parens. That said, the rules are:
1. Although you don't always need them, it is recommended style to always put parentheses
around right-hand values, such as the 7 in num should equal (7):
result should equal (4) array should have length (3) book should have ( 'title ("Programming in Scala"), 'author (List("Odersky", "Spoon", "Venners")), 'pubYear (2008) ) option should be ('defined) catMap should (contain key (9) and contain value ("lives")) keyEvent should be an ('actionKey) javaSet should have size (90)
2. Except for length and size, you must always put parentheses around
the list of one or more property values following a have:
file should (exist and have ('name ("temp.txt"))) book should have ( title ("Programming in Scala"), author (List("Odersky", "Spoon", "Venners")), pubYear (2008) ) javaList should have length (9) // parens optional for length and size
3. You must always put parentheses around and and or expressions, as in:
catMap should (contain key (9) and contain value ("lives")) number should (equal (2) or equal (4) or equal (8))
4. Although you don't always need them, it is recommended style to always put parentheses
around custom Matchers when they appear directly after not:
file should exist file should not (exist) file should (exist and have ('name ("temp.txt"))) file should (not (exist) and have ('name ("temp.txt")) file should (have ('name ("temp.txt") or exist) file should (have ('name ("temp.txt") or not (exist))
That's it. With a bit of practice it should become natural to you, and the compiler will always be there to tell you if you forget a set of needed parentheses.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
Class used via an implicit conversion to enable any two objects to be compared with
=== in assertions in tests.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class supports the syntax of FlatSpec, WordSpec, FixtureFlatSpec,
and FixtureWordSpec.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
This class is part of the ScalaTest matchers DSL.
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.
This method enables the following syntax:
This method enables the following syntax:
num should (not be < (10) and not be > (17))
This method enables the following syntax:
This method enables the following syntax:
num should (not be <= (10) and not be > (17))
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 enables the following syntax:
This method enables the following syntax:
num should not be === (10)
This method enables the following syntax:
This method enables the following syntax:
num should (not be > (10) and not be < (7))
This method enables the following syntax:
This method enables the following syntax:
num should (not be >= (10) and not be < (7))
This field enables the following syntax:
This field enables the following syntax:
badBook should not be a ('goodRead)
This field enables the following syntax:
This field enables the following syntax:
badBook should not be an (excellentRead)
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 enables syntax such as the following:
This method enables syntax such as the following:
obj should (be theSameInstanceAs (string) and be theSameInstanceAs (string))
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.
This method enables syntax such as the following:
This method enables syntax such as the following:
list should (contain ('a') and have length (7))
Implicitly converts an object of type Byte to a BytePlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
Implicitly converts an object of type Byte to a BytePlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
Implicitly converts an object of type Double to a DoublePlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
Implicitly converts an object of type Double to a DoublePlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
Implicitly converts an object of type Float to a FloatPlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
Implicitly converts an object of type Float to a FloatPlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
This implicit conversion method converts an object with a getLength field of type Int to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a getLength field of type Int to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a getLength field of type Long to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a getLength field of type Long to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a getLength method of type Int to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a getLength method of type Int to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a getLength method of type Long to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a getLength method of type Long to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a getSize field of type Int to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a getSize field of type Int to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a getSize field of type Long to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a getSize field of type Long to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a getSize method of type Int to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a getSize method of type Int to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a getSize method of type Long to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a getSize method of type Long to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
Implicitly converts an AnyRef of type T whose structure includes
a getLength val of type Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getLength val of type Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getLength method that results in Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getLength method that results in Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getSize val of type Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getSize val of type Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getSize method that results in Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getSize method that results in Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a length val of type Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a length val of type Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a length method that results in Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a length method that results in Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a size val of type Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a size val of type Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a size method that results in Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a size method that results in Int
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getLength val of type Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getLength val of type Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getLength method that results in Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getLength method that results in Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getSize val of type Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getSize val of type Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getSize method that results in Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a getSize method that results in Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a length val of type Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a length val of type Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a length method that results in Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a length method that results in Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a size val type Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a size val type Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a size method that results in Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an AnyRef of type T whose structure includes
a size method that results in Long
to a SizeShouldWrapper[T], to enable should methods to be invokable on that object.
Implicitly converts an object of type Int to a IntPlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
Implicitly converts an object of type Int to a IntPlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
This implicit conversion method converts an object with a length field of type Int to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a length field of type Int to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a length field of type Long to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a length field of type Long to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a length method of type Int to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a length method of type Int to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a length method of type Long to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
This implicit conversion method converts an object with a length method of type Long to a
LengthWrapper, to enable that object to be used with the have length (7) syntax.
Implicitly converts an object of type Long to a LongPlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
Implicitly converts an object of type Long to a LongPlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
This implicit conversion method enables the following syntax (javaMap is a java.util.Map):
This implicit conversion method enables the following syntax (javaMap is a java.util.Map):
javaMap should (contain key ("two"))
The (contain key ("two")) expression will result in a Matcher[scala.collection.Map[String, Any]]. This
implicit conversion method will convert that matcher to a Matcher[java.util.Map[String, Any]].
Implicitly converts an object of type Short to a ShortPlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
Implicitly converts an object of type Short to a ShortPlusOrMinusWrapper,
to enable a plusOrMinus method to be invokable on that object.
This implicit conversion method converts an object with a size field of type Int to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a size field of type Int to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a size field of type Long to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a size field of type Long to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a size method of type Int to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a size method of type Int to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a size method of type Long to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts an object with a size method of type Long to a
LengthWrapper, to enable that object to be used with the have size (7) syntax.
This implicit conversion method converts a Symbol to a
HavePropertyMatcherGenerator, to enable the symbol to be used with the have ('author ("Dickens")) syntax.
This implicit conversion method converts a Symbol to a
HavePropertyMatcherGenerator, to enable the symbol to be used with the have ('author ("Dickens")) syntax.
Implicitly converts a scala.AnyRef of type T to an AnyRefShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts a scala.AnyRef of type T to an AnyRefShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type T to a AnyShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type T to a AnyShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Array[T] to a ArrayShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Array[T] to a ArrayShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Byte to a ByteShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Byte to a ByteShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Double to a DoubleShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Double to a DoubleShouldWrapper,
to enable should methods to be invokable on that 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 Suites. This is the only implicit conversion that is in scope by default in every
ScalaTest Suite. Other implicit conversions offered by ScalaTest, such as those that support the matchers DSL
or invokePrivate, must be explicitly invited into your test code, either by mixing in a trait or importing the
members of its companion object. The reason ScalaTest requires you to invite in implicit conversions (with the exception of the
implicit conversion for === operator) is because if one of ScalaTest's implicit conversions clashes with an
implicit conversion used in the code you are trying to test, your program won't compile. Thus there is a chance that if you
are ever trying to use a library or test some code that also offers an implicit conversion involving a === operator,
you could run into the problem of a compiler error due to an ambiguous implicit conversion. If that happens, you can turn off
the implicit conversion offered by this convertToEqualizer method simply by overriding the method in your
Suite subclass, but not marking it as implicit:
// In your Suite subclass override def convertToEqualizer(left: Any) = new Equalizer(left)
the object whose type to convert to Equalizer.
Implicitly converts an object of type T to a EvaluatingApplicationShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type T to a EvaluatingApplicationShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Float to a FloatShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Float to a FloatShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Int to a IntShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Int to a IntShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type java.util.Collection[T] to a JavaCollectionShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type java.util.Collection[T] to a JavaCollectionShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type java.util.List[T] to a JavaListShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type java.util.List[T] to a JavaListShouldWrapper[T],
to enable should methods to be invokable on that object. This conversion is necessary to enable
length to be used on Java Lists.
Implicitly converts an object of type java.util.Map[K, V] to a JavaMapShouldWrapper[K, V],
to enable should methods to be invokable on that object.
Implicitly converts an object of type java.util.Map[K, V] to a JavaMapShouldWrapper[K, V],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.List[T] to a ListShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.List[T] to a ListShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Long to a LongShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Long to a LongShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.collection.Map[K, V] to a MapShouldWrapper[K, V],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.collection.Map[K, V] to a MapShouldWrapper[K, V],
to enable should methods to be invokable on that object.
This implicit conversion method enables ScalaTest matchers expressions that involve and and or.
This implicit conversion method enables ScalaTest matchers expressions that involve and and or.
Implicitly converts an object of type scala.Seq[T] to a SeqShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Seq[T] to a SeqShouldWrapper[T],
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Short to a ShortShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Short to a ShortShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type java.lang.String to a StringShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type java.lang.String to a StringShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Collection[T] to a CollectionShouldWrapper,
to enable should methods to be invokable on that object.
Implicitly converts an object of type scala.Collection[T] to a CollectionShouldWrapper,
to enable should methods to be invokable on that object.
This implicit conversion method enables the following syntax:
This implicit conversion method enables the following syntax:
Array(1, 2) should (not contain (3) and not contain (2))
The (not contain ("two")) expression will result in a Matcher[Traversable[String]]. This
implicit conversion method will convert that matcher to a Matcher[Array[String]].
This implicit conversion method enables the following syntax (javaColl is a java.util.Collection):
This implicit conversion method enables the following syntax (javaColl is a java.util.Collection):
javaColl should contain ("two")
The (contain ("two")) expression will result in a Matcher[Traversable[String]]. This
implicit conversion method will convert that matcher to a Matcher[java.util.Collection[String]].
This method enables syntax such as the following:
This method enables syntax such as the following:
string should (endWith ("ago") and include ("score"))
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 enables the following syntax:
This method enables the following syntax:
result should equal (7)
The left should equal (right) syntax works by calling == on the left
value, passing in the right value, on every type except arrays. If left is an array, deepEquals
will be invoked on left, passing in right. Thus, even though this expression
will yield false, because Array's equals method compares object identity:
Array(1, 2) == Array(1, 2) // yields false
The following expression will not result in a TestFailedException, because deepEquals compares
the two arrays structurally, taking into consideration the equality of the array's contents:
Array(1, 2) should equal (Array(1, 2)) // succeeds (i.e., does not throw TestFailedException)
If you ever do want to verify that two arrays are actually the same object (have the same identity), you can use the
be theSameInstanceAs syntax.
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.
This method enables syntax such as the following:
This method enables syntax such as the following:
evaluating { "hi".charAt(-1) } should produce [StringIndexOutOfBoundsException]
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.
This method enables syntax such as the following:
This method enables syntax such as the following:
string should (fullyMatch regex ("Hel*o, wor.d") and not have length (99))
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.
This method enables syntax such as the following:
This method enables syntax such as the following:
list should (have length (3) and not contain ('a'))
This method enables syntax such as the following:
This method enables syntax such as the following:
string should (include ("hope") and not startWith ("no"))
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.
This field enables the following syntax:
This field enables the following syntax:
map should not contain key (10)
This field enables the following syntax:
This field enables the following syntax:
"hi" should not have length (3)
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.
This field enables syntax like the following:
This field enables syntax like the following:
myFile should (not be an (directory) and not have ('name ("foo.bar")))
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.
This method enables the following syntax:
This method enables the following syntax:
evaluating { "hi".charAt(-1) } should produce [StringIndexOutOfBoundsException]
This field enables the following syntax:
This field enables the following syntax:
"eight" should not fullyMatch regex ("""(-)?(\d+)(\.\d*)?""".r)
This field enables the following syntax:
This field enables the following syntax:
set should not have size (3)
This method enables syntax such as the following:
This method enables syntax such as the following:
string should (startWith ("Four") and include ("year"))
This field enables the following syntax:
This field enables the following syntax:
oneString should not be theSameInstanceAs (anotherString)
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.
This field enables the following syntax:
This field enables the following syntax:
map should not contain value (10)
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 provides a domain specific language (DSL) for expressing assertions in tests using the word
should. (If you prefer the wordmust, you can alternatively mix in traitMustMatchers.) For example, if you mixShouldMatchersinto a suite class, you can write an equality assertion in that suite like this:Here
objectis a variable, and can be of any type. If the object is anIntwith the value 3, execution will continue (i.e., the expression will result in the unit value,()). Otherwise, aTestFailedExceptionwill be thrown with a detail message that explains the problem, such as"7 did not equal 3". ThisTestFailedExceptionwill cause the test to fail.The
left should equal (right)syntax works by calling==on theleftvalue, passing in therightvalue, on every type except arrays. Ifleftis an array,deepEqualswill be invoked onleft, passing inright. Thus, even though this expression will yield false, becauseArray'sequalsmethod compares object identity:The following expression will not result in a
TestFailedException, becausedeepEqualscompares the two arrays structurally, taking into consideration the equality of the array's contents:If you ever do want to verify that two arrays are actually the same object (have the same identity), you can use the
be theSameInstanceAssyntax, described below.Checking size and length
You can check the size or length of just about any type of object for which it would make sense. Here's how checking for length looks:
Size is similar:
The
lengthsyntax can be used with any object that has a field or method namedlengthor a method namedgetLength. Similarly, thesizesyntax can be used with any object that has a field or method namedsizeor a method namedgetSize. The type of alengthorsizefield, or return type of a method, must be eitherIntorLong. Any such method must take no parameters. (The Scala compiler will ensure at compile time that the object on whichshouldis being invoked has the appropriate structure.)Checking strings
You can check for whether a string starts with, ends with, or includes a substring like this:
string should startWith ("Hello") string should endWith ("world") string should include ("seven")You can check for whether a string starts with, ends with, or includes a regular expression, like this:
string should startWith regex ("Hel*o") string should endWith regex ("wo.ld") string should include regex ("wo.ld")And you can check whether a string fully matches a regular expression, like this:
string should fullyMatch regex ("""(-)?(\d+)(\.\d*)?""")The regular expression passed following the
regextoken can be either aStringor ascala.util.matching.Regex.Greater and less than
You can check whether any type that is, or can be implicitly converted to, an
Ordered[T]is greater than, less than, greater than or equal, or less than or equal to a value of typeT. The syntax is:Checking equality with
be===An alternate way to check for equality of two objects is to use
bewith===. Here's an example:Here
objectis a variable, and can be of any type. If the object is anIntwith the value 3, execution will continue (i.e., the expression will result in the unit value,()). Otherwise, aTestFailedExceptionwill be thrown with a detail message that explains the problem, such as"7 was not equal to 3". ThisTestFailedExceptionwill cause the test to fail.The
left should be === (right)syntax works by calling==on theleftvalue, passing in therightvalue, on every type except arrays. Ifleftis an array,deepEqualswill be invoked onleft, passing inright. Thus, even though this expression will yield false, becauseArray'sequalsmethod compares object identity:The following expression will not result in a
TestFailedException, becausedeepEqualscompares the two arrays structurally, taking into consideration the equality of the array's contents:If you ever do want to verify that two arrays are actually the same object (have the same identity), you can use the
be theSameInstanceAssyntax, described below.Checking
Booleanproperties withbeIf an object has a method that takes no parameters and returns boolean, you can check it by placing a
Symbol(afterbe) that specifies the name of the method (excluding an optional prefix of "is"). A symbol literal in Scala begins with a tick mark and ends at the first non-identifier character. Thus,'emptyresults in aSymbolobject at runtime, as does'definedand'file. Here's an example:emptySet should be ('empty)Given this code, ScalaTest will use reflection to look on the object referenced from
emptySetfor a method that takes no parameters and results inBoolean, with either the nameemptyorisEmpty. If found, it will invoke that method. If the method returnstrue, execution will continue. But if it returnsfalse, aTestFailedExceptionwill be thrown that will contain a detail message, such as:This
besyntax can be used with any type. If the object does not have an appropriately named predicate method, you'll get aTestFailedExceptionat runtime with a detail message that explains the problem. (For the details on how a field or method is selected during this process, see the documentation forBeWord.)If you think it reads better, you can optionally put
aoranafterbe. For example,java.io.Filehas two predicate methods,isFileandisDirectory. Thus with aFileobject namedtemp, you could write:temp should be a ('file)Or, given
java.awt.event.KeyEventhas a methodisActionKeythat takes no arguments and returnsBoolean, you could assert that aKeyEventis an action key with:keyEvent should be an ('actionKey)If you prefer to check
Booleanproperties in a type-safe manner, you can use aBePropertyMatcher. This would allow you to write expressions such as:These expressions would fail to compile if
shouldis used on an inappropriate type, as determined by the type parameter of theBePropertyMatcherbeing used. (For example,filein this example would likely be of typeBePropertyMatcher[java.io.File]. If used with an appropriate type, such an expression will compile and at run time theBooleanproperty method or field will be accessed directly; i.e., no reflection will be used. See the documentation forBePropertyMatcherfor more information.Using custom
BeMatchersIf you want to create a new way of using
be, which doesn't map to an actual property on the type you care about, you can create aBeMatcher. You could use this, for example, to createBeMatcher[Int]calledodd, which would match any oddInt, andeven, which would match any evenInt. Given this pair ofBeMatchers, you could check whether anIntwas odd or even with expressions like:For more information, see the documentation for
BeMatcher.Checking object identity
If you need to check that two references refer to the exact same object, you can write:
Checking numbers against a range
To check whether a floating point number has a value that exactly matches another, you can use
should equal:Often, however, you may want to check whether a floating point number is within a range. You can do that using
beandplusOrMinus, like this:This expression will cause a
TestFailedExceptionto be thrown if the floating point value,sevenDotOhis outside the range6.7to7.1. You can also useplusOrMinuswith integral types, for example:Traversables, iterables, sets, sequences, and maps
You can use some of the syntax shown previously with
Iterableand its subtypes. For example, you can check whether anIterableisempty, like this:iterable should be ('empty)You can check the length of an
Seq(Array,List, etc.), like this:You can check the size of any
Traversable, like this:In addition, you can check whether an
Iterablecontains a particular element, like this:iterable should contain ("five")You can also check whether a
Mapcontains a particular key, or value, like this:map should contain key (1) map should contain value ("Howdy")Java collections and maps
You can use similar syntax on Java collections (
java.util.Collection) and maps (java.util.Map). For example, you can check whether a JavaCollectionorMapisempty, like this:javaCollection should be ('empty) javaMap should be ('empty)Even though Java's
Listtype doesn't actually have alengthorgetLengthmethod, you can nevertheless check the length of a JavaList(java.util.List) like this:You can check the size of any Java
CollectionorMap, like this:In addition, you can check whether a Java
Collectioncontains a particular element, like this:javaCollection should contain ("five")One difference to note between the syntax supported on Java collections and that of Scala iterables is that you can't use
contain (...)syntax with a JavaMap. Java differs from Scala in that itsMapis not a subtype of itsCollectiontype. If you want to check that a JavaMapcontains a specific key/value pair, the best approach is to invokeentrySeton the JavaMapand check that entry set for the appropriate element (ajava.util.Map.Entry) usingcontain (...).Despite this difference, the other (more commonly used) map matcher syntax works just fine on Java
Maps. You can, for example, check whether a JavaMapcontains a particular key, or value, like this:javaMap should contain key (1) javaMap should contain value ("Howdy")Be as an equality comparison
All uses of
beother than those shown previously perform an equality comparison. In other words, they work the same asequals. This redundance betweenbeandequalsexists because it enables syntax that sometimes sounds more natural. For example, instead of writing:You can write:
(Hopefully you won't write that too much given
nullis error prone, andOptionis usually a better, well, option.) Here are some other examples ofbeused for equality comparison:As with
equal, usingbeon arrays results indeepEqualsbeing called, notequals. As a result, the following expression would not throw aTestFailedException:Because
beis used in several ways in ScalaTest matcher syntax, just as it is used in many ways in English, one potential point of confusion in the event of a failure is determining whetherbewas being used as an equality comparison or in some other way, such as a property assertion. To make it more obvious whenbeis being used for equality, the failure messages generated for those equality checks will include the wordequalin them. For example, if this expression fails with aTestFailedException:The detail message in that
TestFailedExceptionwill include the words"equal to"to signifybewas in this case being used for equality comparison:Being negative
If you wish to check the opposite of some condition, you can simply insert
notin the expression. Here are a few examples:object should not be (null) sum should not be <= (10) mylist should not equal (yourList) string should not startWith ("Hello")Logical expressions with
andandorYou can also combine matcher expressions with
andand/oror, however, you must place parentheses or curly braces around theandororexpression. For example, thisand-expression would not compile, because the parentheses are missing:map should contain key ("two") and not contain value (7) // ERROR, parentheses missing!Instead, you need to write:
map should (contain key ("two") and not contain value (7))Here are some more examples:
number should (be > (0) and be <= (10)) option should (equal (Some(List(1, 2, 3))) or be (None)) string should ( equal ("fee") or equal ("fie") or equal ("foe") or equal ("fum") )Two differences exist between expressions composed of these
andandoroperators and the expressions you can write on regularBooleans using its&&and||operators. First, expressions withandandordo not short-circuit. The following contrived expression, for example, would print"hello, world!":"yellow" should (equal ("blue") and equal { println("hello, world!"); "green" })In other words, the entire
andororexpression is always evaluated, so you'll see any side effects of the right-hand side even if evaluating only the left-hand side is enough to determine the ultimate result of the larger expression. Failure messages produced by these expressions will "short-circuit," however, mentioning only the left-hand side if that's enough to determine the result of the entire expression. This "short-circuiting" behavior of failure messages is intended to make it easier and quicker for you to ascertain which part of the expression caused the failure. The failure message for the previous expression, for example, would be:Most likely this lack of short-circuiting would rarely be noticeable, because evaluating the right hand side will usually not involve a side effect. One situation where it might show up, however, is if you attempt to
andanullcheck on a variable with an expression that uses the variable, like this:map should (not be (null) and contain key ("ouch"))If
mapisnull, the test will indeed fail, but with aNullPointerException, not aTestFailedException. Here, theNullPointerExceptionis the visible right-hand side effect. To get aTestFailedException, you would need to check each assertion separately:map should not be (null) map should contain key ("ouch")If
mapisnullin this case, thenullcheck in the first expression will fail with aTestFailedException, and the second expression will never be executed.The other difference with
Booleanoperators is that although&&has a higher precedence than||,andandorhave the same precedence. Thus although theBooleanexpression(a || b && c)will evaluate the&&expression before the||expression, like(a || (b && c)), the following expression:Will evaluate left to right, as:
If you really want the
andpart to be evaluated first, you'll need to put in parentheses, like this:Working with
OptionsScalaTest matchers has no special support for
Options, but you can work with them quite easily using syntax shown previously. For example, if you wish to check whether an option isNone, you can write any of:option should equal (None) option should be (None) option should not be ('defined) option should be ('empty)If you wish to check an option is defined, and holds a specific value, you can write either of:
option should equal (Some("hi")) option should be (Some("hi"))If you only wish to check that an option is defined, but don't care what it's value is, you can write:
option should be ('defined)Checking arbitrary properties with
haveUsing
have, you can check properties of any type, where a property is an attribute of any object that can be retrieved either by a public field, method, or JavaBean-stylegetorismethod, like this:book should have ( 'title ("Programming in Scala"), 'author (List("Odersky", "Spoon", "Venners")), 'pubYear (2008) )This expression will use reflection to ensure the
title,author, andpubYearproperties of objectbookare equal to the specified values. For example, it will ensure thatbookhas either a public Java field or method namedtitle, or a public method namedgetTitle, that when invoked (or accessed in the field case) results in a the string"Programming in Scala". If all specified properties exist and have their expected values, respectively, execution will continue. If one or more of the properties either does not exist, or exists but results in an unexpected value, aTestFailedExceptionwill be thrown that explains the problem. (For the details on how a field or method is selected during this process, see the documentation forHavePropertyMatcherGenerator.)When you use this syntax, you must place one or more property values in parentheses after
have, seperated by commas, where a property value is a symbol indicating the name of the property followed by the expected value in parentheses. The only exceptions to this rule is the syntax for checking size and length shown previously, which does not require parentheses. If you forget and put parentheses in, however, everything will still work as you'd expect. Thus instead of writing:You can alternatively, write:
If a property has a value different from the specified expected value, a
TestFailedErrorwill be thrown with a detail message that explains the problem. For example, if you assert the following on abookwhose title isMoby Dick:book should have ('title ("A Tale of Two Cities"))You'll get a
TestFailedExceptionwith this detail message:The title property had value "Moby Dick", instead of its expected value "A Tale of Two Cities", on object Book("Moby Dick", "Melville", 1851)If you prefer to check properties in a type-safe manner, you can use a
HavePropertyMatcher. This would allow you to write expressions such as:book should have ( title ("Programming in Scala"), author (List("Odersky", "Spoon", "Venners")), pubYear (2008) )These expressions would fail to compile if
shouldis used on an inappropriate type, as determined by the type parameter of theHavePropertyMatcherbeing used. (For example,titlein this example might be of typeHavePropertyMatcher[org.publiclibrary.Book]. If used with an appropriate type, such an expression will compile and at run time the property method or field will be accessed directly; i.e., no reflection will be used. See the documentation forHavePropertyMatcherfor more information.Using custom matchers
If none of the built-in matcher syntax (or options shown so far for extending the syntax) satisfy a particular need you have, you can create custom
Matchers that allow you to place your own syntax directly aftershould. For example, classjava.io.Filehas a methodexists, which indicates whether a file of a certain path and name exists. Because theexistsmethod takes no parameters and returnsBoolean, you can call it usingbewith a symbol orBePropertyMatcher, yielding assertions like:file should be ('exists) // using a symbol file should be (inExistance) // using a BePropertyMatcherAlthough these expressions will achieve your goal of throwing a
TestFailedExceptionif the file does not exist, they don't produce the most readable code because the English is either incorrect or awkward. In this case, you might want to create a customMatcher[java.io.File]namedexist, which you could then use to write expressions like:// using a plain-old Matcher file should exist file should not (exist) file should (exist and have ('name ("temp.txt")))Note that when you use custom
Matchers, you will need to put parentheses around the custom matcher in more cases than with the built-in syntax. For example you will often need the parentheses afternot, as shown above. (There's no penalty for always surrounding custom matchers with parentheses, and if you ever leave them off when they are needed, you'll get a compiler error.) For more information about how to create customMatchers, please see the documentation for theMatchertrait.Checking for expected exceptions
Sometimes you need to test whether a method throws an expected exception under certain circumstances, such as when invalid arguments are passed to the method. With
ShouldMatchersmixed in, you can check for an expected exception like this:evaluating { s.charAt(-1) } should produce [IndexOutOfBoundsException]If
charAtthrows an instance ofStringIndexOutOfBoundsException, this expression will result in that exception. But ifcharAtcompletes normally, or throws a different exception, this expression will complete abruptly with aTestFailedException. This expression returns the caught exception so that you can inspect it further if you wish, for example, to ensure that data contained inside the exception has the expected values. Here's an example:val thrown = evaluating { s.charAt(-1) } should produce [IndexOutOfBoundsException] thrown.getMessage should equal ("String index out of range: -1")Those pesky parens
Perhaps the most tricky part of writing assertions using ScalaTest matchers is remembering when you need or don't need parentheses, but bearing in mind a few simple rules should help. It is also reassuring to know that if you ever leave off a set of parentheses when they are required, your code will not compile. Thus the compiler will help you remember when you need the parens. That said, the rules are:
1. Although you don't always need them, it is recommended style to always put parentheses around right-hand values, such as the
7innum should equal (7):2. Except for
lengthandsize, you must always put parentheses around the list of one or more property values following ahave:3. You must always put parentheses around
andandorexpressions, as in:4. Although you don't always need them, it is recommended style to always put parentheses around custom
Matchers when they appear directly afternot:That's it. With a bit of practice it should become natural to you, and the compiler will always be there to tell you if you forget a set of needed parentheses.