Plugins cannot add other plugins in config() hook

[marvinhagemeister]

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Describe the bug

If a plugin adds another plugin via the config() hook, then the "inner" one will be ignored. Only the outer plugin will be added. My goal is to create a wrapper plugin for Preact applications that automatically sets up the prefresh plugin, devtools bridge and some custom SSR stuff.

Reproduction

Repro: https://github.com/marvinhagemeister/vite-nested-plugin-bug

1. Clone the repo above
2. Run npm install
3. Run npm start and open the page
4. Page should render "It works!"

System Info

• vite version: 2.0.5
• Operating System: MacOS Big Sur
• Node version: 15.10.0
• Package manager (npm/yarn/pnpm) and version: npm 7.6.1

[marvinhagemeister]

Alright, after lots of experimentation and an attempt to add recursively registering plugins myself, I've come to the conclusion that this would open up a can of worms. It makes config creation a lot more complex and it's unclear in which order some hooks should be processed. Much easier if the plugin tree remains flat.

Instead I found another neat way to enable presets: mergeConfig(). With that we can just pass a config around and extend it:

function withPreset(config) {
  return mergeConfig(config, {
	plugins: [foo(), bar()]
  }
);

// vite.config.ts
export default withPreset({
  // user config
})

With this the feature request becomes redundant.