Provides a migration function, exported as `migrate` from `svelte/compiler`, which tries its best to automatically migrate towards runes, render tags (instead of slots) and event attributes (instead of event handlers)
The preview REPL was updated with a migrate button so people can try it out in the playground.
closes #9239
* failing test for :is(...)
* simplify
* trim
* factor out truncate function
* pass stylesheet around
* recurse into :is and :where
* fix types
* fix types
* almost there
* gah so close
* tada
* changeset
* simplify
* feat: nested CSS support (#10491)
* parse nested CSS
* tests
* track parent rules
* some progress
* switch it up
* pruning
* works
* changeset
* lint
* error early on invalid nesting selector
* tidy
* note to self
* fix some specificity stuff
* failing test
* note to self
* fix: correctly scope CSS selectors with descendant combinators (#10502)
* fix traversal, but break some other stuff
* man this is fucken hard
* fixes
* getting closer
* be conservative for now
* tidy
* invert
* invert
* simplify
* switch
* for now
* progress
* i think it works?
* fix
* tidy up
* revert some stuff
* remove some junk
* handle weird cases
* update
* tweak
* shrink
* changeset
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
* Update playgrounds/sandbox/run.js
* changeset
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
