fix(vite): subscribe rollup:reload to hot-reload after updateConfig

[danielroe]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

spotted in nuxt - calling updateConfig did nothing when using with nitro/vite.

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

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Project	Deployment	Actions	Updated (UTC)
nitro.build	Ready	Preview	Jul 31, 2026 8:49pm

[coderabbitai]

📝 Walkthrough

Walkthrough

The Vite development server now invokes its debounced reload workflow on Nitro rollup:reload events. A new integration test verifies that dynamic updateConfig({ routeRules }) changes update endpoint response headers.

Changes

Vite development reload updates

Layer / File(s)	Summary
Nitro reload hook wiring src/build/vite/dev.ts	Registers a rollup:reload hook that triggers the existing debounced reload workflow.
Dynamic route rule integration coverage test/vite/update-config.test.ts	Starts a Vite server, checks the initial response, updates routeRules, and polls until the x-extend header appears.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• nitrojs/nitro#4387: Both changes modify the Vite development reload workflow, but use different hooks and behavior.
• nitrojs/nitro#4411: Both changes address Vite/Nitro route-rule reload behavior and add related testing.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title follows Conventional Commits syntax and clearly describes the Vite hot-reload fix.
Description check	✅ Passed	The description identifies the nitro/vite updateConfig bug and explains that the change enables hot reload.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/vite-dev-update-config

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commit: 6b17505

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@test/vite/update-config.test.ts`:
- Line 27: Restore the original process working directory after the test setup
that calls process.chdir(rootDir), ensuring cleanup runs after the affected
tests complete so later tests are not left resolving paths from the fixture
directory.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 65368265-b9c3-4233-a67c-52ae3a93f00f

📥 Commits

Reviewing files that changed from the base of the PR and between 77b77ff and 6b17505.

📒 Files selected for processing (2)

• src/build/vite/dev.ts
• test/vite/update-config.test.ts