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Unit Test for a Language which cross-references an Ecore model [message #1745193]

Thu, 06 October 2016 08:58

Desmond Hume

Messages: 9
Registered: October 2016

Junior Member

Dear all,

given a xtext grammar which references an ecore model such as the following works just fine when running Eclipse.

Model:
	'MyModel' myModel=[ecore::EPackage] '{' ... '}'
;

However, how do I unit test such a language? I came across some previous threads which discussed the testing of languages with cross-references to other xtext languages.

There you had to create a ResourceSet and pass it to the ParseHelper<>.parse method. Unfortunately, that does not work for Ecore resources because they cannot be casted to XtextResources and therefore "resource.contents.head.assertNoIssues" results in a ClassCastException: "org.eclipse.emf.ecore.xmi.impl.EcoreResourceFactoryImpl$1 cannot be cast to org.eclipse.xtext.resource.XtextResource".

Is there another way to create a ResourceSet with an Ecore model?

class LanguageParsingTest {

	@Inject extension ParseHelper<MyModel> 
	@Inject extension ValidationTestHelper

	@Inject
	Provider<XtextResourceSet> resourceSetProvider;
	
	@Test
	def void testParsing() {
		val fooPackage = EcoreFactory::eINSTANCE.createEPackage
		fooPackage.name = "foo"
		fooPackage.nsPrefix ="foo"
		fooPackage.nsURI = "http://foo"

		val resourceSet = resourceSetProvider.get
		val resource = resourceSet.createResource(URI.createURI("foo.ecore"))
		resource.contents.add(fooPackage)
		resource.save(null)

		resourceSet.getPackageRegistry().put(fooPackage.getNsURI(), fooPackage);
		resource.load(null);

		resource.contents.head.assertNoIssues

		val model = '''MyModel foo { }'''.parse(resourceSet)
		model.assertNotNull
		model.assertNoErrors	
	}
}

Thank you very much for your help!

[Updated on: Thu, 06 October 2016 17:59]

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Re: Unit Test for a Language which cross-references an Ecore model [message #1745229 is a reply to message #1745193]

Thu, 06 October 2016 16:40

Christian Dietrich

Messages: 14492
Registered: July 2009

Senior Member

i dont know of a "super duper easy one method make me happy way" that you might be looking for,
although one could surely optimize / restructure etc what you are doing.
(e.g. by having a parse method that takes both the ecore and the text)

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Re: Unit Test for a Language which cross-references an Ecore model [message #1745230 is a reply to message #1745229]

Thu, 06 October 2016 16:50

Christian Dietrich

Messages: 14492
Registered: July 2009

Senior Member

of regarding your error in the first place.
of course you could try to make places like org.eclipse.xtext.testing.validation.ValidationTestHelper.validate(Resource) and maybe others more robust.
can you elaborate where the classcast exception actually happens?

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Re: Unit Test for a Language which cross-references an Ecore model [message #1745235 is a reply to message #1745230]

Thu, 06 October 2016 18:48

Desmond Hume

Messages: 9
Registered: October 2016

Junior Member

Thanks for your reply Christian!

The exception is indeed thrown by ValidationTestHelper.validate(Resource) as the EMF resource is casted to a XtextResource.

However, I have to admit that I made a small mistake when explaining my problem. Please ignore the 'head.assertNoIssues line, .parse(resourceSet)' line for a second. The 'assertNoErrors' in the last line also invokes the ValidationTestHelper.validate method. The result is "[ERROR:Couldn't resolve reference to EPackage 'foo'." When debugging that error, it seems that it fails to lazy load the ecore resource even though I didn't figure out the reason why it fails.

That's why I was wondering if there is another way to create a ResourceSet with an Ecore model?

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Re: Unit Test for a Language which cross-references an Ecore model [message #1745239 is a reply to message #1745235]

Thu, 06 October 2016 19:32

Christian Dietrich

Messages: 14492
Registered: July 2009

Senior Member

do you have org.eclipse.xtext.ecore added to the test project. do you call ecoreSupport somewhere? eg.

@RunWith(XtextRunner)
@InjectWith(ExtendedMyDslInjectorProvider)
class DemoTest {

@Inject extension ParseHelper<Model>
@Inject extension ValidationTestHelper

@Inject
Provider<XtextResourceSet> resourceSetProvider;

@Test
def void testParsing() {
val fooPackage = EcoreFactory::eINSTANCE.createEPackage
fooPackage.name = "foo"
fooPackage.nsPrefix ="foo"
fooPackage.nsURI = "http://foo"
val resourceSet = resourceSetProvider.get
val resource = resourceSet.createResource(URI.createURI("foo.ecore"))
resource.contents.add(fooPackage)
val model = '''MyModel foo { }'''.parse(resourceSet)
model.assertNotNull
model.assertNoErrors
}

}

class ExtendedMyDslInjectorProvider extends MyDslInjectorProvider {

override protected internalCreateInjector() {
return new MyDslStandaloneSetup() {

override register(Injector injector) {
EcoreSupportStandaloneSetup.setup
super.register(injector)
}

}.createInjectorAndDoEMFRegistration();
}

}

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