Avoid using updateContentScripts() as it suffers from an unexpected
behavior, causing injected content scripts to lose proper order
at injection time. The order in which content scripts are injected
is key for uBOL content scripts. Potential out of order injection
was causing cosmetic filtering to be broken.
Use actual storage API to persist data across service worker
wake-ups and browser launches. uBOL was trying to avoid using
storage API, at the cost of somewhat hacky code (using DNR API
to persist settings).
Make use of session storage if available, to speed up
initialization of waking up the service worker (which at this
point is necessary to properly implement cosmetic filtering).
What does not work at the time of commit:
Cosmetic filtering does not work:
The content scripts responsible for cosmetic filtering fail when
trying to inject the stylesheets through document.adoptedStyleSheets,
with the following error message:
XrayWrapper denied access to property Symbol.iterator
(reason: object is not safely Xrayable).
See https://developer.mozilla.org/en-US/docs/Xray_vision for more
information. ... css-declarative.js:106:8
A possible solution is to inject those content scripts in the
MAIN world. However Firefox scripting API does not support MAIN
world injection at the moment.
Scriptlet-filtering does not work:
Because scriptlet code needs to be injected in the MAIN world,
and this is currently not supported by Firefox's scripting API,
see https://bugzilla.mozilla.org/show_bug.cgi?id=1736575
There is no count badge on the toolbar icon in Firefox, as it
currently does not support the `DNR.setExtensionActionOptions`
method.
Other than the above issues, it does appear uBO is blocking
properly with no error reported in the dev console.
The adoptedStyleSheets issue though is worrisome, as the
cosmetic filtering content scripts were designed with ISOLATED
world injection in mind. Being forced to inject in MAIN world
(when available) make things a bit more complicated as uBO
has to ensure it's global variables do not leak into the page.
