chore: add PluginWithRequiredHook type & extract getHookHandler function

[lzt1008]

Description

This PR mainly refactors the code to extract the common getHookHandler utility to get hook from object style hooks.

The repeated pattern of:

'handler' in hook ? hook.handler : hook

is extracted into getHookHandler with correct TypeScript type to reduce duplication.

This PR also added a WithRequiredHook type to get a more precise plugin type when requiring the specific hook.

Based on this if statement, we can guarantee that all returned Plugins has the hook of hookName.

vite/packages/vite/src/node/plugins/index.ts

Lines 145 to 157 in 90e6108

	if (hook) {
	if (typeof hook === 'object') {
	if (hook.order === 'pre') {
	pre.push(plugin)
	continue
	}
	if (hook.order === 'post') {
	post.push(plugin)
	continue
	}
	}
	normal.push(plugin)
	}

We should pass this information on in subsequent code. Equally, getHookHandler's extraction relies on this more precise return type

This PR is a pure refactoring to improve code structure. No behavior or functionality changes.

Additional context

One usage haven't refactor to getHookHandler directly due to its different implementation, I've marked with TODO to align in a follow up.

vite/packages/vite/src/node/plugins/index.ts

Lines 123 to 125 in 7950636

	return typeof hook === 'object' && 'handler' in hook
	? hook.handler
	: hook

Additionally, The implementation of object style hook in Rollup is:

const handler = typeof hook === 'object' ? hook.handler : hook;

https://github.com/rollup/rollup/blob/fbf806aceffd822d43e4603b664c54165c72cf36/src/utils/PluginDriver.ts#L322

Comparing the two implementations of Vite, which one is the best?

hook === 'object' && 'handler' in hook ? hook.handler : hook 

'handler' in hook ? hook.handler : hook

If someone wrote a plugin like this, Vite will act different with Rollup, should we keep this 'handler' in hook logic?

const plugin = () => {
  const p = {
    resolveId() {
      console.log('call function')
    }
  }
  p.resolveId.handler = function() {
      console.log('call handler')
  }
  return p
}

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[patak-dev]

Thanks for the PR! This looks like a great refactoring to me, and it shows some inconsistencies as you described. I think we should change the implementation to match Rollup's version. If the hook is a function, I think it should be called and not go with its .handler even if it is there.

[bluwy]

I was also thinking if we should handle if fn is undefined here, but I suppose the types always restricts that you need a handler with the object-form, so I suppose this is also fine for now.