Request + URLSearchParams doesn't work as expected with polyfill-library + core-js

[romainmenke]

test : BodyInit unions URLSearchParams

(function (cb) {
	new Request('#', { body: new URLSearchParams({ foo: 'baz' }), method: 'POST' }).text().then(function(x) {
                // x is an empty string
		cb(x === 'foo=baz');
	});
})(callback);

core-js only wraps window.fetch without patching other parts like Request.

Unsure at this point how to resolve.

• use URLSearchParams from polyfill-library and exclude the one from core-js
• patch core-js so that Request works as expected.
• patch detect script in fetch polyfill.

[romainmenke]

Numbers going up : 9cf0720