vite build causes OOMs due to spawning deno info with unbounded concurrency.

[jhgg]

When using this plugin, we notice that builds OOM, because too many deno info processes are spawned. This causes >8GB of memory pressure on our build machine, which kills the build :(

In addition, build times are significantly slower due to having to call out to info for every dependency. This slows down our build significantly, taking the total vite build time from ~2.43s to 20s on my machine.

[Garciat]

I also noticed way slower builds:

With plugin:

➜  deno task build
Task build deno run -A npm:vite build
vite v6.2.0 building for production...
✓ 1650 modules transformed.
dist/index.html                   0.43 kB │ gzip:  0.28 kB
dist/assets/index-D7fEyQzs.css   10.50 kB │ gzip:  2.07 kB
dist/assets/index-CrJfWa1s.js   317.15 kB │ gzip: 96.32 kB
✓ built in 26.81s

Without plugin:

➜  deno task build
Task build deno run -A npm:vite build
vite v6.2.0 building for production...
✓ 1650 modules transformed.
dist/index.html                   0.43 kB │ gzip:  0.28 kB
dist/assets/index-RZhrGdRc.css   10.43 kB │ gzip:  2.04 kB
dist/assets/index-C6cbh9Sm.js   317.19 kB │ gzip: 96.33 kB
✓ built in 1.26s

[Garciat]

I found a workaround for my case.

My deno.json file contained the following and I wanted that to be honored by Vite.

  "imports": {
    "src/": "./src/",
    "lib/": "./lib/"
  },

And I found that I can do that with resolve.alias:

export default defineConfig({
  plugins: [react()],
  resolve: {
    alias: {
      "lib": import.meta.resolve("./lib"),
      "src": import.meta.resolve("./src"),
    },
  },
});

[lbsal]

For what it's worth:

We've forked this at https://github.com/masslbs/deno-vite-plugin and published the fork so that it can be used by ci: https://www.npmjs.com/package/@masslbs/deno-vite-plugin

Info from the fork's README:

Care has been taken to avoid introducing changes in the final output arrived at by running this version of deno-vite-plugin compared to the upstream version. The result of this fork is that it uses a bounded amount of memory and its execution time is faster after a first run has populated the cache.

This fork:

• uses a lock to limit external calls to deno info --json
• improves how the in-memory cache is used by catching more cases
• implements an on-disk cache, speeding up initial loading considerably

The on-disk cache is only written after a clean exit from vite, or when the server restarts as that is when Rollup's buildEnd phase runs.

Prevent the on-disk cache from being used by setting the environment variable NOCACHE e.g. NOCACHE="1" deno run dev. This can be helpful if debugging any build errors that may/may not have to do with caching.

Logging what the plugin is doing at any point in time can be enabled by providing DEBUG=deno-vite-plugin or DEBUG=*.