fix(ssr): hoist import statements to the top

[btea]

Description

fix #10444

Additional context

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the PR Title Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[stackblitz]

Run & review this pull request in StackBlitz Codeflow.

[patak-dev]

/ecosystem-ci run

[vite-ecosystem-ci]

📝 Ran ecosystem CI: Open

suite	result
astro	❌ failure
histoire	❌ failure
iles	✅ success
ladle	✅ success
laravel	✅ success
marko	✅ success
nuxt-framework	❌ failure
previewjs	✅ success
qwik	✅ success
rakkas	✅ success
sveltekit	✅ success
vite-plugin-ssr	❌ failure
vite-plugin-react	❌ failure
vite-plugin-react-pages	❌ failure
vite-plugin-react-swc	✅ success
vite-plugin-svelte	✅ success
vite-plugin-vue	✅ success
vite-setup-catalogue	✅ success
vitepress	✅ success
vitest	❌ failure
windicss	✅ success

[patak-dev]

cc @sheremet-va, I don't think this would affect vite-node but good to be aware of this change.

[sheremet-va]

cc @sheremet-va, I don't think this would affect vite-node but good to be aware of this change.

Will not affect vite-node, but will break Vitest module mocking (vi.mock) 😄

[patak-dev]

I need the 😬 emoji reaction to add to your response. How do we handle this merge to avoid issues in Vitest? Could vi.mock be updated to cope with this change and we delay merging until 4.3?

[sheremet-va]

Could vi.mock be updated to cope with this change and we delay merging until 4.3?

There is a way to make it work with both versions, yes. Previously it relied on a behavior that SSR transform will not affect imports position, so "vi.mock" was hoisted before any "import" in the source code, and not in the transformed code and it was done as a Vite plugin.

Now we will need to move it after the code is transformed and also somehow merge source maps, which was handled by Vite previously.

[patak-dev]

@sheremet-va do you think we can move forward with this PR in 4.3? The stable cut for it may be released in 2-3 weeks.

[sheremet-va]

@sheremet-va do you think we can move forward with this PR in 4.3? The stable cut for it may be released in 2-3 weeks.

Should be fine if CI is passing

[patak-dev]

/ecosystem-ci run vitest

[vite-ecosystem-ci]

📝 Ran ecosystem CI: Open

suite	result
vitest	✅ success