prepend should throw when prepending a Text node to Document

[Ryosuke Niwa]

document.createElement('div').prepend(document.createElement('span')) should throw HierarchyRequestError when ensureing pre-insertion validity.

This bug was found by the newly added test: LayoutTests/http/tests/w3c/dom/nodes/prepend-on-Document.html

[Radar WebKit Bug Importer]

<rdar://problem/22570226>

[Chris Dumez]

(In reply to comment #0)
> document.createElement('div').prepend(document.createElement('span')) should
> throw HierarchyRequestError when ensureing pre-insertion validity.
> 
> This bug was found by the newly added test:
> LayoutTests/http/tests/w3c/dom/nodes/prepend-on-Document.html

The case you're mentioning seems like it should work and I don't see anything in the spec [1] saying it shouldn't. Looking at http/tests/w3c/dom/nodes/prepend-on-Document.html, I see the following test case:
===
    test(function() {
        var parent = node.cloneNode();
        var x = document.createElement('x');
        parent.prepend(x);
        assert_array_equals(parent.childNodes, [x]);
    }, 'Document.prepend() with only one element as an argument, on a Document having no child.');
===

This seems to be the case you mention and the test does not expect an exception.

[1] https://dom.spec.whatwg.org/#concept-node-ensure-pre-insertion-validity

[Chris Dumez]

Maybe you were referring to the following check in the test?
===
    test(function() {
        var parent = node.cloneNode();
        assert_throws('HierarchyRequestError', function() { parent.prepend('text'); });
        assert_array_equals(parent.childNodes, []);
    }, 'Document.prepend() with text as an argument, on a Document having no child.');
===

If so, the reason this is expected to throw is because the parent is a Document and the child is a Text Node (step 5 of https://dom.spec.whatwg.org/#concept-node-ensure-pre-insertion-validity).

[Ryosuke Niwa]

Fixed in https://trac.webkit.org/changeset/189682.