Add variant support to // META

[annevk]

This blocks landing web-platform-tests/wpt#5148 / fixing web-platform-tests/wpt#2557 properly.

[jdm]

Somehow we need to interact with

wpt-tools/manifest/sourcefile.py

Lines 363 to 381 in 3decb95

	@cached_property
	def variant_nodes(self):
	"""List of ElementTree Elements corresponding to nodes representing a
	test variant"""
	return self.root.findall(".//{http://www.w3.org/1999/xhtml}meta[@name='variant']")
	@cached_property
	def test_variants(self):
	rv = []
	for element in self.variant_nodes:
	if "content" in element.attrib:
	variant = element.attrib["content"]
	assert variant == "" or variant[0] in ["#", "?"]
	rv.append(variant)
	if not rv:
	rv = [""]
	return rv

.

[annevk]

Since it ends up writing out a container HTML for the worker resource as well, I suppose we can plug in the meta elements there.

@jgraham was also talking about combining the HTML wrapper .any.js tests so you only have a single file in which case this would just work (though not for .worker.js I suppose).

[jgraham]

Writing the meta stuff in the wrapper document doesn't work because that doesn't exist until runtime and this needs to go in the manifest so it knows which tests exist. You need to make the changes in manifest/sourcefile.py so that variant is a supported meta value and each variant is added as a different test in the manifest.

[wpt-issue-mover]

This issue has been moved to web-platform-tests/wpt#7210; please continue all discussion there.