In Firefox these return empty arrays and it would be nice if Safari were to follow suit now that plugins are removed. (Safari still seems to return something for PDF.) See also https://github.com/whatwg/html/issues/6003.
<rdar://problem/73276215>
Chrome canary seems to also have pdf-related things. I suspect that they'll run into the compatibility issues that Ryosuke mentioned in GitHub, but when the time comes that they do it and find no compatibility issues I have nothing against trying.
We've updated the spec to now instead have a hard-coded lists of plugins (either 0 or 5) for web compatibility, with the idea that all browsers have those 5 plugins. We've also added navigator.pdfViewerSupported as a boolean for simpler feature detection going forward. * Spec PR: https://github.com/whatwg/html/pull/6738 * New spec: https://html.spec.whatwg.org/multipage/system-state.html#pdf-viewing-support * Tests: https://github.com/web-platform-tests/wpt/pull/29559 (not yet reviewed/merged)
Safari is failing these in WPT test cases - https://wpt.fyi/results/html/webappapis/system-state-and-capabilities/the-navigator-object/plugins-and-mimetypes.html?label=master&label=experimental&aligned&q=navigator Can we align with other browsers? It can be used as potential fingerprinting.
This work (to match spec) is covered under Bug 245396, so I'm going to dupe there. *** This bug has been marked as a duplicate of bug 245396 ***