Use FileReader in macOS native apps using WebKit

[rajivshah3]

In a macOS native app that uses WebKit, calling saveAs on a Blob attempts to open the blob URL. This results in a message that says There is no application set to open the URL blob:http... (see iotaledger-archive/spark-wallet#89 (comment)).

As in Safari, the FileReader API should be used. However, changes need to be made to the browser detection because of a few differences between Safari and WebKit:

• HTMLAnchorElement.download is defined
• typeof FileReader returns 'function' instead of 'object'

With these changes, the expected behavior is achieved:

Fixes #509

[Floriferous]

I have a similar issue where HTMLAnchorElement itself is undefined in a node test environment, could we also first check if it exists before trying to access its prototype?

Like this:
HTMLAnchorElement && !isWebKit && ('download' in HTMLAnchorElement.prototype)

I suggest the isWebkit check is done before trying to find 'download', as isWebKit is a boolean that has already been calculated, so no need to perform the in operation if it is not needed.

[jdeanquin-dg]

I have a similar issue where HTMLAnchorElement itself is undefined in a node test environment, could we also first check if it exists before trying to access its prototype?

Like this:
HTMLAnchorElement && !isWebKit && ('download' in HTMLAnchorElement.prototype)

I suggest the isWebkit check is done before trying to find 'download', as isWebKit is a boolean that has already been calculated, so no need to perform the in operation if it is not needed.

Hello @Floriferous I have submitted a PR to fix the problem in node environments since my tests were failing even if not trying to test FileSaver at all #620 620

[eligrey]

lgtm 👍 - I will merge your changes once you bump the version

[rajivshah3]

@eligrey will do. Do you want me to rebuild the dist as well?

[eligrey]

Yeah, you should also re-build dist.

Make sure that you also maintain compatibility with iOS as per #577. I don't have an iOS device to test.

Thanks for taking the time to PR!

[rajivshah3]

@eligrey just tested, still works on iOS Chrome