Refresh on Access does not work for Xtext editors

[cdietrich]

Refresh on Access does not work for Xtext editors

(2) configure workspace for refresh on access
(1) open a Xtext based dsl file
(2) modify on disk
(3) click into the editor

Expected behaviour:
Editor refreshes (e.g. as .java or .txt)
Actual behaviour:
Editor does not refresh

This is caused by the customization in

org.eclipse.xtext.ui.editor.model.XtextDocumentProvider.isSynchronized(Object)

i have no idea why the code there is like it is and what doing some copy&paste from superclass would break

Question: can the XtextDocumentProvider be fixed without breaking something else

[szarnekow]

see also https://bugs.eclipse.org/bugs/show_bug.cgi?id=326961

[cdietrich]

@szarnekow are you actively working on this?

[szarnekow]

Not on the fix for the current impl in isolation, no

[iloveeclipse]

This is caused by the customization in
org.eclipse.xtext.ui.editor.model.XtextDocumentProvider.isSynchronized(Object)
i have no idea why the code there is like it is and what doing some copy&paste from superclass would break
Question: can the XtextDocumentProvider be fixed without breaking something else

That is what we've also just found. We plan to provide a PR that should fix that, current state is just not acceptable from the user point of view.

[mehmet-karaman]

Removing the isSynchronized implementation and make use of its super implementation works. But for the case if the editor was dirty and the file was edited outside of eclipse, the user gets a dialog in which he can choose loading of the new content or ignore the change. If the user selects to ignore the changes, the dirty editor can't save it anymore, because the file is out of sync. So I am going to investigate this problem too.

[mehmet-karaman]

@szarnekow
I guess this ticket can be closed now?

[szarnekow]

Indeed. Thank you for the heads-up.

[LorenzoBettini]

@mehmet-karaman one of the added tests seems to be flaky (especially in macOS):

java.lang.AssertionError
	at org.junit.Assert.fail(Assert.java:87)
	at org.junit.Assert.assertTrue(Assert.java:42)
	at org.junit.Assert.assertFalse(Assert.java:65)
	at org.junit.Assert.assertFalse(Assert.java:75)
	at org.eclipse.xtext.ui.tests.editor.DirtyStateEditorSupportIntegrationTest.testModifyFileInExternEditor(DirtyStateEditorSupportIntegrationTest.java:148)

maybe some refresh should be explicitly executed before the assertion?

[mehmet-karaman]

I am going to check this.

[LorenzoBettini]

@mehmet-karaman sorry to go back to this, but org.eclipse.xtext.ui.tests.editor.DirtyStateEditorSupportIntegrationTest.testModifyFileInExternEditor() is still very flaky on GitHub Actions in macOS. There's still something wrong with that test (there's some missed synchronization...).

expected:<[stuff foo]> but was:<[]>
org.junit.ComparisonFailure: expected:<[stuff foo]> but was:<[]>
	at org.junit.Assert.assertEquals(Assert.java:117)
	at org.junit.Assert.assertEquals(Assert.java:146)
	at org.eclipse.xtext.ui.tests.editor.DirtyStateEditorSupportIntegrationTest.testModifyFileInExternEditor(DirtyStateEditorSupportIntegrationTest.java:155)

I guess that the assertEquals is using wrong arguments:

assertEquals(document.get(), "");

should be

assertEquals("", document.get());

shouldn't it?

[LorenzoBettini]

Shouldn't syncUtil.waitForReconciler(editor); be executed before checking document's contents?

[mehmet-karaman]

Thanks for the hints.. Created a new PR which contains these changes: #3275