Reduce first load JS on blog posts by 53% #15
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This could also be aliased similarly to "ts" in Code.tsx. Anyway, without this fix you'll get errors in the following commits.
This component defers loading most of the syntax highlighting code until after the page loads, and it will only download syntaxes that are used on the page. It comes with a tradeoff though: syntax highlighting no longer works with client JS disabled, i.e. the code blocks sent from the server are not highlighted.
PrismLight will have access to all syntaxes on the server side and provide syntax-highlighted code blocks in HTML. PrismAsyncLight will download only the necessary syntaxes on the client to hydrate the code blocks. This seems to work fine right here, but I noticed some server/client mismatches in dev on my own site. There are PRs up to fix those problems: react-syntax-highlighter/react-syntax-highlighter#361 react-syntax-highlighter/react-syntax-highlighter#362
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Sounds good to me! |
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There are a couple small changes you can make to the react-syntax-highlighter imports that massively improve the bundle size for blog post pages. There are some minor tradeoffs, but I think this is a better default behavior.
I wrote a blog post about this with screenshots of the PageSpeed score impact on my repo along with some other changes (69 -> 98). This is basically a backport of some commits in this PR. The bundlewatch output from reverting one of the commits can be seen here.