Why does the error method return an error? - xtext

Question

I want to validate input corresponding to the following grammar snippet:
Declaration:
name = ID "=" brCon=BracketContent
;
BracketContent:
decCon=DecContent (comp+=COMPARATOR content+=DecContent)*
;
DecContent:
(neg=("!"|"not"))? singleContent=VarContent (op+=OPERATOR nextCon+=VarContent)*
;
My validation looks like that:
#Check
def checkNoCycleInHierarchy(Declaration dec) {
if(dec.decCon.singleContent.reference == null) {
return
}
var names = newArrayList
var con = dec.decCon.singleContent
while(con.reference != null) {
con = getThatReference(con).singleContent
if(names.contains(getParentName(con))) {
val errorMsg = "Cycle in hierarchy!"
error(errorMsg,
SQFPackage.eINSTANCE.bracketContent_DecCon,
CYCLE_IN_HIERARCHY)
return
}
names.add(getParentName(con))
}
}
But when I test this validation with a testCaseit returns me an error message:
Expected ERROR 'raven.sqf.CycleInHierarchy' on Declaration at [-1:-1] but got
ERROR (org.eclipse.emf.ecore.impl.EClassImpl#5a7fe64f (name: Declaration) (instanceClassName: null) (abstract: false, interface: false).0) 'Error executing EValidator', offset null, length null
ERROR (org.eclipse.emf.ecore.impl.EClassImpl#5a7fe64f (name: Declaration) (instanceClassName: null) (abstract: false, interface: false).0) 'Error executing EValidator', offset null, length null
I just can't figure out what's wrong with it so I hope that someone of you might have an idea.
Greetings Krzmbrzl

Answer 1

You test utility tells you that the validator did not produce the expected validation error ("CycleInHierarchy").
Instead, the validator produced the error "Error executing EValidator".
Which means an exception has been thrown when your validator was executed.

Answer 2

It turned out it was an internal error...I'm still not exactly sure what went wrong but I have rewritten my validation method and now it works as expected.
Now the method looks like this:
enter code here#Check
def checkNoCycleInHierarchy(Declaration dec) {
if(dec.varContent.reference == null) {
//proceed only if there is a reference
return
}
var content = dec.varContent
var names = newArrayList
while(content.reference != null && !names.contains(getParentName(content))) {
names.add(getParentName(content))
content = content.reference.varContent
if(names.contains(getParentName(content))) {
val errorMsg = "Cycle in hierarchy!"
error(errorMsg,
SQFPackage.eINSTANCE.declaration_BrCon,
CYCLE_IN_HIERARCHY)
return
}
}
}
I have the suspicion that there was a problem with the usage of my "getThatReference" in this case.
Greeting Krzmbrzl