MatchResult

The result of a match operation, such as one performed by a Matcher or BeMatcher, which contains one field that indicates whether the match succeeded, four fields that provide raw failure messages to report under different circumstances, four fields providing arguments used to construct the final failure messages using raw failure messages and a Prettifier. Using the default constructor, failure messages will be constructed lazily (when required).

A MatchResult's matches field indicates whether a match succeeded. If it succeeded, matches will be true. There are four methods, failureMessage, negatedfailureMessage, midSentenceFailureMessage and negatedMidSentenceFailureMessage that can be called to get final failure message strings, one of which will be presented to the user in case of a match failure. If a match succeeds, none of these strings will be used, because no failure message will be reported (i.e., because there was no failure to report). If a match fails (matches is false), the failureMessage (or midSentenceFailure—more on that below) will be reported to help the user understand what went wrong.

Understanding `negatedFailureMessage`

The negatedFailureMessage exists so that it can become the failureMessage if the matcher is inverted, which happens, for instance, if it is passed to not. Here's an example:

val equalSeven = equal (7)
val notEqualSeven = not (equalSeven)

The Matcher[Int] that results from passing 7 to equal, which is assigned to the equalSeven variable, will compare Ints passed to its apply method with 7. If 7 is passed, the equalSeven match will succeed. If anything other than 7 is passed, it will fail. By contrast, the notEqualSeven matcher, which results from passing equalSeven to not, does just the opposite. If 7 is passed, the notEqualSeven match will fail. If anything other than 7 is passed, it will succeed.

For example, if 8 is passed, equalSeven's MatchResult will contain:

           expression: equalSeven(8)
              matches: false
       failureMessage: 8 did not equal 7
negatedFailureMessage: 8 equaled 7

Although the negatedFailureMessage is nonsensical, it will not be reported to the user. Only the failureMessage, which does actually explain what caused the failure, will be reported by the user. If you pass 8 to notEqualSeven's apply method, by contrast, the failureMessage and negatedFailureMessage will be:

           expression: notEqualSeven(8)
              matches: true
       failureMessage: 8 equaled 7
negatedFailureMessage: 8 did not equal 7

Note that the messages are swapped from the equalSeven messages. This swapping was effectively performed by the not matcher, which in addition to swapping the failureMessage and negatedFailureMessage, also inverted the matches value. Thus when you pass the same value to both equalSeven and notEqualSeven the matches field of one MatchResult will be true and the other false. Because the matches field of the MatchResult returned by notEqualSeven(8) is true, the nonsensical failureMessage, "8 equaled 7", will not be reported to the user.

If 7 is passed, by contrast, the failureMessage and negatedFailureMessage of equalSeven will be:

           expression: equalSeven(7)
              matches: true
       failureMessage: 7 did not equal 7
negatedFailureMessage: 7 equaled 7

In this case equalSeven's failureMessage is nonsensical, but because the match succeeded, the nonsensical message will not be reported to the user. If you pass 7 to notEqualSeven's apply method, you'll get:

           expression: notEqualSeven(7)
              matches: false
       failureMessage: 7 equaled 7
negatedFailureMessage: 7 did not equal 7

Again the messages are swapped from the equalSeven messages, but this time, the failureMessage makes sense and explains what went wrong: the notEqualSeven match failed because the number passed did in fact equal 7. Since the match failed, this failure message, "7 equaled 7", will be reported to the user.

Understanding the "`midSentence`" messages

When a ScalaTest matcher expression that involves and or or fails, the failure message that results is composed from the failure messages of the left and right matcher operatnds to and or or. For example:

8 should (equal (7) or equal (9))

This above expression would fail with the following failure message reported to the user:

8 did not equal 7, and 8 did not equal 9

This works fine, but what if the failure messages being combined begin with a capital letter, such as:

The name property did not equal "Ricky"

A combination of two such failure messages might result in an abomination of English punctuation, such as:

The name property did not equal "Ricky", and The name property did not equal "Bobby"

Because ScalaTest is an internationalized application, taking all of its strings from a property file enabling it to be localized, it isn't a good idea to force the first character to lower case. Besides, it might actually represent a String value which should stay upper case. The midSentenceFailureMessage exists for this situation. If the failure message is used at the beginning of the sentence, failureMessage will be used. But if it appears mid-sentence, or at the end of the sentence, midSentenceFailureMessage will be used. Given these failure message strings:

           failureMessage: The name property did not equal "Bobby"
midSentenceFailureMessage: the name property did not equal "Bobby"

The resulting failure of the or expression involving to matchers would make any English teacher proud:

The name property did not equal "Ricky", and the name property did not equal "Bobby"

matches: indicates whether or not the matcher matched
rawFailureMessage: raw failure message to report if a match fails
rawNegatedFailureMessage: raw message with a meaning opposite to that of the failure message
rawMidSentenceFailureMessage: raw failure message suitable for appearing mid-sentence
rawMidSentenceNegatedFailureMessage: raw negated failure message suitable for appearing mid-sentence
failureMessageArgs: arguments for constructing failure message to report if a match fails
negatedFailureMessageArgs: arguments for constructing message with a meaning opposite to that of the failure message
midSentenceFailureMessageArgs: arguments for constructing failure message suitable for appearing mid-sentence
midSentenceNegatedFailureMessageArgs: arguments for constructing negated failure message suitable for appearing mid-sentence
prettifier: a Prettifier to prettify arguments before constructing the messages

Source: MatchResult.scala

Linear Supertypes

Serializable, Serializable, Product, Equals, AnyRef, Any

Instance Constructors

new MatchResult(matches: Boolean, rawFailureMessage: String, rawNegatedFailureMessage: String)

Constructs a new MatchResult with passed matches, rawFailureMessage, and rawNegativeFailureMessage fields.
Constructs a new MatchResult with passed matches, rawFailureMessage, and rawNegativeFailureMessage fields. The rawMidSentenceFailureMessage will return the same string as rawFailureMessage, and the rawMidSentenceNegatedFailureMessage will return the same string as rawNegatedFailureMessage. failureMessageArgs, negatedFailureMessageArgs, midSentenceFailureMessageArgs, midSentenceNegatedFailureMessageArgs will be Vector.empty and Prettifier.default will be used.
matches
indicates whether or not the matcher matched
rawFailureMessage
raw failure message to report if a match fails
rawNegatedFailureMessage
raw message with a meaning opposite to that of the failure message
new MatchResult(matches: Boolean, rawFailureMessage: String, rawNegatedFailureMessage: String, rawMidSentenceFailureMessage: String, rawMidSentenceNegatedFailureMessage: String, failureMessageArgs: IndexedSeq[Any], negatedFailureMessageArgs: IndexedSeq[Any], midSentenceFailureMessageArgs: IndexedSeq[Any], midSentenceNegatedFailureMessageArgs: IndexedSeq[Any], prettifier: Prettifier = Prettifier.default)

matches
indicates whether or not the matcher matched
rawFailureMessage
raw failure message to report if a match fails
rawNegatedFailureMessage
raw message with a meaning opposite to that of the failure message
rawMidSentenceFailureMessage
raw failure message suitable for appearing mid-sentence
rawMidSentenceNegatedFailureMessage
raw negated failure message suitable for appearing mid-sentence
failureMessageArgs
arguments for constructing failure message to report if a match fails
negatedFailureMessageArgs
arguments for constructing message with a meaning opposite to that of the failure message
midSentenceFailureMessageArgs
arguments for constructing failure message suitable for appearing mid-sentence
midSentenceNegatedFailureMessageArgs
arguments for constructing negated failure message suitable for appearing mid-sentence
prettifier
a Prettifier to prettify arguments before constructing the messages

Value Members

final def !=(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def ##(): Int

Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def failureMessage: String

Construct failure message to report if a match fails, using rawFailureMessage, failureMessageArgs and prettifier
Construct failure message to report if a match fails, using rawFailureMessage, failureMessageArgs and prettifier
returns
failure message to report if a match fails
val failureMessageArgs: IndexedSeq[Any]

arguments for constructing failure message to report if a match fails
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
val matches: Boolean

indicates whether or not the matcher matched
def midSentenceFailureMessage: String

Construct failure message suitable for appearing mid-sentence, using rawMidSentenceFailureMessage, midSentenceFailureMessageArgs and prettifier
Construct failure message suitable for appearing mid-sentence, using rawMidSentenceFailureMessage, midSentenceFailureMessageArgs and prettifier
returns
failure message suitable for appearing mid-sentence
val midSentenceFailureMessageArgs: IndexedSeq[Any]

arguments for constructing failure message suitable for appearing mid-sentence
def midSentenceNegatedFailureMessage: String

Construct negated failure message suitable for appearing mid-sentence, using rawMidSentenceNegatedFailureMessage, midSentenceNegatedFailureMessageArgs and prettifier
Construct negated failure message suitable for appearing mid-sentence, using rawMidSentenceNegatedFailureMessage, midSentenceNegatedFailureMessageArgs and prettifier
returns
negated failure message suitable for appearing mid-sentence
val midSentenceNegatedFailureMessageArgs: IndexedSeq[Any]

arguments for constructing negated failure message suitable for appearing mid-sentence
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def negated: MatchResult

Get a negated version of this MatchResult, matches field will be negated and all messages field will be substituted with its counter-part.
Get a negated version of this MatchResult, matches field will be negated and all messages field will be substituted with its counter-part.
returns
a negated version of this MatchResult
def negatedFailureMessage: String

Construct message with a meaning opposite to that of the failure message, using rawNegatedFailureMessage, negatedFailureMessageArgs and prettifier
Construct message with a meaning opposite to that of the failure message, using rawNegatedFailureMessage, negatedFailureMessageArgs and prettifier
returns
message with a meaning opposite to that of the failure message
val negatedFailureMessageArgs: IndexedSeq[Any]

arguments for constructing message with a meaning opposite to that of the failure message
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
val prettifier: Prettifier

a Prettifier to prettify arguments before constructing the messages
a Prettifier to prettify arguments before constructing the messages
val rawFailureMessage: String

raw failure message to report if a match fails
val rawMidSentenceFailureMessage: String

raw failure message suitable for appearing mid-sentence
val rawMidSentenceNegatedFailureMessage: String

raw negated failure message suitable for appearing mid-sentence
val rawNegatedFailureMessage: String

raw message with a meaning opposite to that of the failure message
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

Understanding negatedFailureMessage

Understanding the "midSentence" messages

Instance Constructors

new MatchResult(matches: Boolean, rawFailureMessage: String, rawNegatedFailureMessage: String)

Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

def clone(): AnyRef

final def eq(arg0: AnyRef): Boolean

def failureMessage: String

val failureMessageArgs: IndexedSeq[Any]

def finalize(): Unit

final def getClass(): Class[_]

final def isInstanceOf[T0]: Boolean

val matches: Boolean

def midSentenceFailureMessage: String

val midSentenceFailureMessageArgs: IndexedSeq[Any]

def midSentenceNegatedFailureMessage: String

val midSentenceNegatedFailureMessageArgs: IndexedSeq[Any]

final def ne(arg0: AnyRef): Boolean

def negated: MatchResult

def negatedFailureMessage: String

val negatedFailureMessageArgs: IndexedSeq[Any]

final def notify(): Unit

final def notifyAll(): Unit

val prettifier: Prettifier

val rawFailureMessage: String

val rawMidSentenceFailureMessage: String

val rawMidSentenceNegatedFailureMessage: String

val rawNegatedFailureMessage: String

final def synchronized[T0](arg0: ⇒ T0): T0

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from Serializable

Inherited from Serializable

Inherited from Product

Inherited from Equals

Inherited from AnyRef

Inherited from Any

Ungrouped

Understanding `negatedFailureMessage`

Understanding the "`midSentence`" messages