Ky: `document` is not available in WebWorkers on Safari which leads to TypeError

[fgreinus]

Hello folks,

I stumbled upon a really strange bug, that only occurred in WebWorkers when using Safari (Desktop).
At this point https://github.com/sindresorhus/ky/blob/master/index.js#L262 ky accesses the document object. There is a check for it, but in case it is not present, globals.document && globals.document.baseURI returns false. But i think Safari expects a string or undefined, because it throws a Type Error at exactly this position. https://developer.mozilla.org/en-US/docs/Web/API/URL/URL this is the documentation for the URL class.

Am i right with my findings? If so, i'd be willing to submit a PR.

Thanks for the awesome package and for your help in advance!

Edit: I just realized, that globals.document && globals.document.baseURI returns undefined in case of globals.document not being existant. So I really have no idea now why Safari throws a TypeError.

[sholladay]

Does it work if input is an absolute URL? The type error may be happening because neither argument to new URL() includes a protocol.

We could work around this by parsing the URL manually, but it's a bit hacky. I desperately want a URL constructor that handles relative URLs. new URL(new Request(myUrl).url) works, but is ugly.

[szmarczak]

Can you put the error here? It would be very helpful to investigate the issue.

[fgreinus]

Hey, input already is an absolute URL. To reproduce the problem you can just enter
new URL('http://google.com', undefined);
into the web developer console. You'll get this:

This works perfectly fine in Firefox. So it seems to be Safari-only behavior.

This is from the Safari Developer Tools. At this line the TypeError is thrown.

[sholladay]

Confirmed. Thanks for the repro.

Unfortunately, this seems to be a bug in Safari, and I believe it violates the specification.

I did come up with a potential workaround, though...

diff --git a/index.js b/index.js
index badfca6..a5bdae0 100644
--- a/index.js
+++ b/index.js
@@ -259,7 +259,7 @@ class Ky {
            this._input = this._options.prefixUrl + this._input;

            if (searchParams) {
-               const url = new URL(this._input, globals.document && globals.document.baseURI);
+               const url = new URL(new Request(this._input).url);
                if (typeof searchParams === 'string' || (URLSearchParams && searchParams instanceof URLSearchParams)) {
                    url.search = searchParams;
                } else if (Object.values(searchParams).every(param => typeof param === 'number' || typeof param === 'string')) {

What's nice about this is that the Request class actually handles the base URL stuff for us automatically.

It would be great if you could tell me what new Request('/foo').url does inside of a Safari WebWorker. Hopefully it just passes the relative URL right through (as Deno does) rather than throwing an error.

Regardless, I will implement this after the request work in PR #180 lands, as it's a nice simplification.

[fgreinus]

It would be great if you could tell me what new Request('/foo').url does inside of a Safari WebWorker. Hopefully it just passes the relative URL right through (as Deno does) rather than throwing an error.

Does not throw an error.
console.log(new Request('/foo').url); prints https://localhost:8000/foo in usual Safari context, as well as in WebWorker.

Also:
Much thanks for your fast reply and for the fix! 👍

[sholladay]

Nice. 👌

You're welcome! PR coming in the next day or two, which will include fixes for a few issues, including this one.