Support setting `src` prefix for manifest generation

[typed-sigterm]

I'm using AssetPack + Pixi.js + Nuxt latest. I have entry: './app/resources', output: './public/packed', the assets are served on http://localhost:8508/packed/**

But AseetPack generated http://localhost:8508/packed/manifest.json is like:

{
  "bundles": [
    {
      "name": "default",
      "assets": [
        {
          "alias": [
            "cards"
          ],
          "src": [
            "cards-0.webp.json"
          ],
          "data": {
            "tags": {
              "tps": true
            }
          }
        }
      ]
    }
  ]
}

So when I'm at http://localhost:8508/rooms/1 Pixi.js always tries to fetch http://localhost:8508/rooms/1/cards-0.webp.json, not http://localhost:8508/packed/cards-0.webp.json. If there's a option to specify the prefix of src, the problem will be solved by setting it to /packed/.

[wighawag]

I got the same issue, it would be great to be able to specify a prefix for the src. Right now I have to post-process the file

[roy232828]

Here is my workaround:

async function prefixManifestSrc(manifestPath: string, prefix: string) {
  const manifest = JSON.parse(await fs.readFile(manifestPath, 'utf-8'));
  for (const bundle of manifest.bundles) {
    for (const asset of bundle.assets) {
      asset.src = asset.src.map((src: string) => `${prefix}${src}`);
    }
  }
  await fs.writeFile(manifestPath, JSON.stringify(manifest));
}

function assetpackPlugin(): Plugin {
  let ap: AssetPack | undefined;

  return {
    name: 'vite-plugin-assetpack',
    async buildStart() {
      if (this.meta.watchMode) {
        if (ap) return;
        ap = new AssetPack(assetpackConfig);
        void ap.watch(() => {
          prefixManifestSrc('./public/assets/manifest.json', '/assets/');
        });
      } else {
        await new AssetPack(assetpackConfig).run();
        await prefixManifestSrc('./public/assets/manifest.json', '/assets');
      }
    },
    async buildEnd() {
      if (ap) {
        await ap.stop();
        ap = undefined;
      }
    },
  };
}