fix: replace import.meta.hot with undefined in the production

[xunmi1]

Description

import.meta.hot is replaced with false when building the production, not undefined.

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

Line 54 in 29abeea

'import.meta.hot': `false`,

Additional context

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Pull Request Guidelines and follow the Commit Convention.
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• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
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[sapphi-red]

I think this is a good change because this will prevent people to write import.meta.hot?.accept that doesn't work. (related: #9235)

[bluwy]

I thought this could initially break things, but given import.meta.hot?.doesn't work, I think this should be safe and consider it as a bug fix.

[patak-dev]

Let's merge this in 4.1 too 👍🏼

[antfu]

Shouldn't we instead replace import.meta.hot with undefined? I think import.meta.hot should be optional, as it could be undefined when a module didn't get into Vite's pipeline.

[antfu]

Rejecting to bring up the discussion.

[xunmi1]

I'm at a loss 🤔, choose to modify the type, not the value being replaced

1. Avoid breaking more things
2. Guide users to use condition judgment rather than optional chaining to facilitate tree shaking

[antfu]

Rollup wasn't tree-shake optional chaining, I guess that would be the reason why false was picked over undefined at the beginning. Made a PR to fix it:

rollup/rollup#4797

After that, I think we could replace import.meta.hot with undefiend instead.

[sapphi-red]

Maybe we need to update this part to support import.meta.hot?..

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

Lines 404 to 427 in 5444781

	// check import.meta usage
	if (rawUrl === 'import.meta') {
	const prop = source.slice(end, end + 4)
	if (prop === '.hot') {
	hasHMR = true
	if (source.slice(end + 4, end + 11) === '.accept') {
	// further analyze accepted modules
	if (source.slice(end + 4, end + 18) === '.acceptExports') {
	lexAcceptedHmrExports(
	source,
	source.indexOf('(', end + 18) + 1,
	acceptedExports,
	)
	isPartiallySelfAccepting = true
	} else if (
	lexAcceptedHmrDeps(
	source,
	source.indexOf('(', end + 11) + 1,
	acceptedUrls,
	)
	) {
	isSelfAccepting = true
	}
	}

[antfu]

We could have that in another PR, so this is not blocking