####
Review patches required for previewing site CSS changes
* [[https://gerrit.wikimedia.org/r/#/c/340768/|340768 (core): Generalize ResourceLoader 'excludepage' functionality]] (@Krinkle)
* [[https://gerrit.wikimedia.org/r/#/c/340769/|340769 (TemplateSandbox): Use new OutputPage::addContentOverride to allow previewing edits to JS/CSS]] (@Tgr)
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#### other patches which used to be part of this task, but not anymore:
>
> * use post-cache transform instead of splitting the parser cache:
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/399907/|399907 (core): Add 'unwrap' ParserOutput post-cache transform]]~~
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/399909/|399909 (CiteThisPage): Use 'unwrap' post-cache transform instead of setWrapOutputClass( false )]]~~
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/399910/|399910 (MobileFrontend): Use 'unwrap' post-cache transform instead of setWrapOutputClass( false ), when available]]~~ (CI issues reported as T186284)
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/399912/|399912 (TemplateStyles): Use 'unwrap' post-cache transform instead of setWrapOutputClass( false )]]~~
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/399914/|399914 (Wikibase): Use 'unwrap' post-cache transform instead of setWrapOutputClass( false )]]~~ (ci issues reported in T186286)
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/399908/|399908 (core): Remove wrapclass from parser cache key]]~~
> * style deduplication:
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/394369/|394369 (TemplateStyles): Cache processed stylesheets during the parse]]~~
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/393283/|393283 (MobileFrontend): ApiMobileView: Disable 'deduplicateStyles' ParserOutput::getText() transformation]]~~
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/393284/|393284 (core): ParserOutput: Add 'deduplicateStyles' post-cache transformation]]~~
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/393285/|393285 (TemplateStyles): Deduplicate embedded style rules]]~~
> * post-cache transforms followup (not strictly related, but tech debt reduction for something that was introduced in part due to TemplateStyles):
> ** ~~[[https://gerrit.wikimedia.org/r/#/c/393262/|393262 (core): Warn if stateful ParserOutput transforms are used]]~~
> ** [[https://gerrit.wikimedia.org/r/#/c/393263/|393263 (core): Hard-deprecate ParserOutput stateful transform methods]] (probably in a separate MW release)
> * [[https://gerrit.wikimedia.org/r/#/c/352835/|352835 (core): Add mw-parser-output to indicators container]] (needs to be rewritten)
> * [[https://gerrit.wikimedia.org/r/#/c/347442/|347442 (core): ResourceLoader: Add wildcard modules]] (should be reviewed by an RL maintainer; not TemplateStyles related)