ValidatorTester and AssertableDiagnostics deprecated

[LorenzoBettini]

https://github.com/eclipse/xtext/blob/652c2c41499387ab87737143d12939a8bdab41ab/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/validation/AssertableDiagnostics.java and https://github.com/eclipse/xtext/blob/652c2c41499387ab87737143d12939a8bdab41ab/org.eclipse.xtext.junit4/src/org/eclipse/xtext/junit4/validation/ValidatorTester.java were deprecated in 2.30 as part as the old org.eclipse.xtext.junit4 bundle.

In org.eclipse.xtext.testing we now have
https://github.com/eclipse/xtext/blob/652c2c41499387ab87737143d12939a8bdab41ab/org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/validation/AssertableDiagnostics.java but no corresponding ValidatorTester, which was the only one creating objects of AssertableDiagnostics.

We still use ValidatorTester in our own tests (we copied it there): https://github.com/eclipse/xtext/blob/652c2c41499387ab87737143d12939a8bdab41ab/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/ValidatorTester.java#L29

Why don't we put the latter in org.eclipse.xtext.testing?

It is not straightforward to port existing tests using ValidatorTester to ValidationTestHelper.

[szarnekow]

Please add a convenient substitute for the deprecated ValidationTester.

[LorenzoBettini]

I was suggesting to use the one we already use in our tests https://github.com/eclipse/xtext/blob/652c2c41499387ab87737143d12939a8bdab41ab/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/ValidatorTester.java#L29

I mean: put that one in the org.eclipse.xtext.testing. I seem to understand that it is exactly the same as the deprecated one.

[szarnekow]

Yes, please.