Jan Schulz

Dim value as Variant
value = "Hallo"
Call assertThat(value, is_( not_( equalTo("Hallo") ) ).and_(is_(ofType("String")))

Resulting in output like this:

(bold is from the Matcher (second argument to assertThat), rest from the Error, which the assertThat method throws)

The Implementation is quite easy: you have a IMatcher abstract Class with several concrete matcher implementation and a static method, which returns a object of that matcher. The IsMatcher (just to have proper english sentences and the static method looks like this:

Public Function is_(matcher As IMatcher) As IMatcher
	Set is_  = New IsMatcher(matcher)
End Function

Class IsMatcher As IMatcher
	Private fMatcher As IMatcher
	
	Sub new(matcher As IMatcher) 
		Set fMatcher = matcher
	End Sub
	
	Public Function matchesSafely( value As Variant) As Boolean
		matchesSafely = fMatcher.matches(value)
	End Function

	Public Function describeMeTo(description As Description)
		description.appendText("is")
		Call fMatcher.describeTo(description)
	End Function
End Class

The testThat (just returns a boolean, assertThat uses that to throw the error) is just:

Public Function testThat(value As Variant, matcher As IMatcher) As Boolean
	testThat = matcher.matches(value)
End Functio

IMatcher.matches(variant) is a wrapper to get the IMatcher.and_(IMatcher) and IMatcher.Or_(IMatcher) methods working. In the end it returns the logical result of all included Matchers.

The IMatcher.decribeMeTo(Description) is again the internal method (describeTo(...) is the wrapper to get AND and OR working) used to get the plain english description from the matcher composite (the bold Text above).

Dim oDescription As New Description
Call matcher.describeTo(oDescription)
print oDescription.toString() 

Implemented Matchers up to now: is, not, equalTo, ofType, instanceOf, like. Feel free to add some matchers or leave a comment for other ideas

Edited, as I can upload now: LS-Hamcrest.lss