fn:base-uri should not raise XPDY0002 when the context item is empty

[adamretter]

Closes #3497

[line-o]

Nice!
I would personally split the test case resolveBaseURIErrorCases in to two or even three separate tests.
One for ()/fn:base-uri() (one for ()/fn:base-uri(.)) and one for fn:base-uri(.) (fn:base-uri() seems to be untested).
Especially, since the first two are not error cases.
Generally, because a test should assert one single thing. But that would mean three separate tests.
On a side note: why is the test implemented in Java instead of adding those tests to the XQSuite?

[adamretter]

@line-o The existing tests for fn:base-uri were already in Java, so I continued that way for continuity. Also I still don't trust XQSuite entirely.

Many of the Java tests assert behaviour rather than a single thing, so I don't think my approach is wrong necessarily.

[dizzzz]

Ok for me

[joewiz]

@line-o I see your agenda item from Monday's call:

I would suggest to stick to XQSuite tests wherever possible because they are more accessible to developers unfamiliar with java.

I don't see any notes detailing whether this was discussed, but it seems to be a good suggestion going forward - which I would articulate as: use xqsuite as a default, with the caveats that of course there may be compelling reasons to do otherwise, such as continuity/grouping with other similar tests (so as not to split substantively similar tests across different locations), or to test functionality that xqsuite cannot handle.

Since we already have working tests here that meet this principle and have secured approval, I will merge this PR.

[adamretter]

@joewiz I actually really strongly disagree. As an eXist-db developer, XQSuite tests are horrible to debug, the ones written from Java are much easier to work with. Also I don't trust that XQSuite doesn't still have some false-positives etc. If our XQuery implementation were more spec compliant, I might begin to trust XQSuite further.

[joewiz]

@adamretter Re: test suites, let's discuss this at a community call. Since there were no notes, I presume it wasn't discussed, so the agenda item will carry forward to next week's call.