Trait extended by matcher objects, which may appear after the word be, that can match against a Boolean
property. The match will succeed if and only if the Boolean property equals true.
The object containing the property, which must be of the type specified by the BePropertyMatcher's type
parameter T, is passed to the BePropertyMatcher's
apply method. The result is a BePropertyMatchResult.
A BePropertyMatcher is, therefore, a function from the specified type, T, to
a BePropertyMatchResult.
Although BePropertyMatcher
and Matcher represent similar concepts, they have no inheritance relationship
because Matcher is intended for use right after should or must
whereas BePropertyMatcher is intended for use right after be.
A BePropertyMatcher essentially allows you to write statically typed Boolean
property assertions similar to the dynamic ones that use symbols:
tempFile should be a ('file) // dynamic: uses reflection
tempFile should be a (file) // type safe: only works on Files; no reflection used
One good way to organize custom matchers is to place them inside one or more traits that
you can then mix into the suites or specs that need them. Here's an example that
includes two BePropertyMatchers:
trait CustomMatchers { class FileBePropertyMatcher extends BePropertyMatcher[java.io.File] {
def apply(left: java.io.File) = BePropertyMatchResult(left.isFile, "file")
}
class DirectoryBePropertyMatcher extends BePropertyMatcher[java.io.File] {
def apply(left: java.io.File) = BePropertyMatchResult(left.isDirectory, "directory")
}
val file = new FileBePropertyMatcher
val directory = new DirectoryBePropertyMatcher
}
Because the type parameter of these two BePropertyMatchers is java.io.File, they
can only be used with instances of that type. (The compiler will enforce this.) All they do is create a
BePropertyMatchResult whose matches field is true if and only if the Boolean property
is true. The second field, propertyName, is simply the string name of the property.
The file and directory vals create variables that can be used in
matcher expressions that test whether a java.io.File is a file or a directory. Here's an example:
class ExampleSpec extends Spec with ShouldMatchers with CustomMatchers { describe("A temp file") {
it("should be a file, not a directory") {
val tempFile = java.io.File.createTempFile("delete", "me")
try {
tempFile should be a (file)
tempFile should not be a (directory)
}
finally {
tempFile.delete()
}
}
}
}
These matches should succeed, but if for example the first match, tempFile should be a (file), were to fail, you would get an error message like:
/tmp/delme1234me was not a file
For more information on BePropertyMatchResult and the meaning of its fields, please
see the documentation for BePropertyMatchResult. To understand why BePropertyMatcher
is contravariant in its type parameter, see the section entitled "Matcher's variance" in the
documentation for Matcher.
Check to see if a Boolean property on the specified object, objectWithProperty, matches its
expected value, and report the result in
the returned BePropertyMatchResult. The objectWithProperty is
usually the value to the left of a should or must invocation. For example, tempFile
would be passed as the objectWithProperty in:
Check to see if a Boolean property on the specified object, objectWithProperty, matches its
expected value, and report the result in
the returned BePropertyMatchResult. The objectWithProperty is
usually the value to the left of a should or must invocation. For example, tempFile
would be passed as the objectWithProperty in:
tempFile should be a (file)
the object with the Boolean property against which to match
the BePropertyMatchResult that represents the result of the match
Compose this BePropertyMatcher with the passed function, returning a new BePropertyMatcher.
Compose this BePropertyMatcher with the passed function, returning a new BePropertyMatcher.
This method overrides compose on Function1 to
return a more specific function type of BePropertyMatcher.
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.
Trait extended by matcher objects, which may appear after the word
be, that can match against aBooleanproperty. The match will succeed if and only if theBooleanproperty equalstrue. The object containing the property, which must be of the type specified by theBePropertyMatcher's type parameterT, is passed to theBePropertyMatcher'sapplymethod. The result is aBePropertyMatchResult. ABePropertyMatcheris, therefore, a function from the specified type,T, to aBePropertyMatchResult.Although
BePropertyMatcherandMatcherrepresent similar concepts, they have no inheritance relationship becauseMatcheris intended for use right aftershouldormustwhereasBePropertyMatcheris intended for use right afterbe.A
BePropertyMatcheressentially allows you to write statically typedBooleanproperty assertions similar to the dynamic ones that use symbols:tempFile should be a ('file) // dynamic: uses reflection tempFile should be a (file) // type safe: only works on Files; no reflection usedOne good way to organize custom matchers is to place them inside one or more traits that you can then mix into the suites or specs that need them. Here's an example that includes two
BePropertyMatchers:trait CustomMatchers {class FileBePropertyMatcher extends BePropertyMatcher[java.io.File] { def apply(left: java.io.File) = BePropertyMatchResult(left.isFile, "file") }
class DirectoryBePropertyMatcher extends BePropertyMatcher[java.io.File] { def apply(left: java.io.File) = BePropertyMatchResult(left.isDirectory, "directory") }
val file = new FileBePropertyMatcher val directory = new DirectoryBePropertyMatcher }
Because the type parameter of these two
BePropertyMatchers isjava.io.File, they can only be used with instances of that type. (The compiler will enforce this.) All they do is create aBePropertyMatchResultwhosematchesfield istrueif and only if theBooleanproperty istrue. The second field,propertyName, is simply the string name of the property. Thefileanddirectoryvals create variables that can be used in matcher expressions that test whether ajava.io.Fileis a file or a directory. Here's an example:class ExampleSpec extends Spec with ShouldMatchers with CustomMatchers {describe("A temp file") {
it("should be a file, not a directory") {
val tempFile = java.io.File.createTempFile("delete", "me")
try { tempFile should be a (file) tempFile should not be a (directory) } finally { tempFile.delete() } } } }
These matches should succeed, but if for example the first match,
tempFile should be a (file), were to fail, you would get an error message like:For more information on
BePropertyMatchResultand the meaning of its fields, please see the documentation forBePropertyMatchResult. To understand whyBePropertyMatcheris contravariant in its type parameter, see the section entitled "Matcher's variance" in the documentation forMatcher.