Fix create_metadata output

[artonge]

The upgrade to xmlbuilder2 broke some generated XMLs, the metadata is part of them as of AuthNRequest, there is probably more if the XML is build with arrays.

Explanation:

Given this code:

root.ele({
  number: [ 
    "one", 
    "two",
    { three: { "@val": 3 } }
  ]
});

xmlbuilder used to render array like that:

<number>
  <one/>
  <two/>
  <three val="3"/>
</number>

And xmlbuilder2 now renders them like that:

<number>one</number>
<number>two</number>
<number>
  <three val="3"/>
</number>

There was the flag separateArrayItems in xmlbuilder to change the behavior but I do not see it in xmlbuilder2. The only option seems to fix all XMLs generation code if it uses arrays.

[mcab]

Ah, yikes! Thanks for the speedy PR; I thought test cases properly covered all of the xmlbuilder uses.

Can we create a case for create_metadata() in tests to capture this regression?

EDIT: working on a test case for this currently.

[artonge]

I think the update to xmlbuilder2 also removed some non essential properties, like on the keys nodes. I did not investigate that.

[mcab]

That's really unfortunate. I'm going to reopen that as an issue to check, and work on that separate from this immediate PR.

If you believe the test case covers the regression, I'd be happy to merge this in.

[artonge]

The test case should do it.

I feel like the best would probably be to compare the output with an expected string. But maybe that's for another issue 😉