refactor(importAnalysis): cache injected env string

[sun0day]

Description

Dedupe the env string constructing logic in importAnalysis

Additional context

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[sun0day]

Is !!config.ssr equal options.ssr?

[bluwy]

Is !!config.ssr equal options.ssr?

No, the config.ssr config could be set, but the same whole Vite config could be used to process client-side files too, so you'd need to rely on options.ssr instead.

[bluwy]

@sun0day after a bit of thought, I figured it's better to cache it lazily since there's a good chance Vite apps don't use import.meta.env at all. Let me know what you think of the new changes!

[sun0day]

@sun0day after a bit of thought, I figured it's better to cache it lazily since there's a good chance Vite apps don't use import.meta.env at all. Let me know what you think of the new changes!

Nice catch. LGTM.