feat: add build.getPublicHash option

[aleclarson]

Generate a revision hash for each asset in the public directory.

import revHash from 'rev-hash'
import fs from 'fs'

export default {
  build: {
    getPublicHash: file => revHash(fs.readFileSync(file)),
  },
}

Features

• Easy HTTP caching of public/ assets. Cache forever, effortless "invalidation".
• Internal: Avoids checkPublicFile calls when building, thereby reducing FS calls.

[yyx990803]

I don't know about this. Assets referenced from imports are already auto-hashed. So this means anything under assets are hashed - you just need to configure cache headers for those files.

The whole point of public is for those files that need to preserve exact filenames. It doesn't make sense to hash them.

[aleclarson]

I've been using public/ for all of the .svg, .png, and fonts in my website, since it takes zero configuration for short import paths (eg: /svg/foo.svg), and I prefer keeping static assets out of the src directory (without having both a public directory and an assets directory).

The alternatives are:

• use relative import paths (less elegant, harder to maintain)
• use paths feature in tsconfig.json and install vite-tsconfig-paths
• custom plugin that rewrites /svg/* imports to config.root + "/assets/svg/[name]"

[aleclarson]

@knightly-bot build this

[yyx990803]

I would prefer this to be a 3rd party plugin to not break the originally intended usage of public.

[aleclarson]

I tried that approach first, but it's not currently possible. If we had a hook for rewriting public filenames (eg: resolvePublicId), it would be pretty easy, I think.

I still think having it built-in is better, since it lets us avoid checkPublicFile calls in build mode.

[aleclarson]

Removed the assetsCopied hook, in favor of publicUrls object added to ResolvedConfig.

[aleclarson]

Closed in favor of #1647 and #1648