[url] Let URLSearchParams accept an init string with leading '?' (#81)

(not sure if this is the best place to put this)

Looking at the spec and test they don't explicitly mention anything about leading `?`

https://url.spec.whatwg.org/#interface-urlsearchparams
https://github.com/w3c/web-platform-tests/blob/master/url/urlsearchparams-get.html

In the current Firefox stable implementation this happens:

`new URLSearchParams('a=1&b=2').get('a') == 1`
`new URLSearchParams('?a=1&b=2').get('a') == null`
`new URLSearchParams('?a=1&b=2').get('?a') == 1`

IMO it would be good to skip leading `?` if present and return this instead

`new URLSearchParams('?a=1&b=2').get('a') == 1`
`new URLSearchParams('?a=1&b=2').get('?a') == null`

The reason is that `window.location.search` returns `?a=1&b=2` with leading `?`.
For consistency the URLSearchParams constructor should allow the leading `?`.

What do you think?

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Reply to this email directly or view it on GitHub:
https://github.com/whatwg/url/issues/81