fix(nuxt): make middleware _path property configurable for HMR

[Flo0806]

🔗 Linked issue

fix #33378

📚 Description

Fixes "Cannot redefine property: _path" error during HMR when CSS changes trigger middleware module reload.

Problem

When CSS files change, Vite-Node triggers HMR and reloads the middleware module. The _path property was defined without configurable: true, causing TypeErrors when the property was redefined in the same context.

Solution

Add configurable: true to both Object.defineProperty calls in the middleware template, allowing properties to be safely redefined during HMR.

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Walkthrough

The change updates two Object.defineProperty invocations in packages/nuxt/src/core/templates.ts to include configurable: true for the _path property. This applies to the global middleware object and the dynamically wrapped named middleware. The control flow and structure remain the same, and no exported or public entity signatures were modified.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Linked Issues Check	⚠️ Warning	The changes implement the required fix by adding the configurable: true flag to the middleware _path property, preventing the TypeError during CSS-triggered HMR, but the PR does not include automated tests to reproduce and verify the HMR edit flow as requested in the linked issue (#33378).	Add automated tests that reproduce the CSS edit HMR scenario and verify that redefining _path no longer throws an error to fully satisfy the linked issue requirements.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title Check	✅ Passed	The title clearly describes the primary change by stating that the middleware _path property is now configurable for HMR in Nuxt, and it concisely conveys the main focus of the fix without superfluous details.
Out of Scope Changes Check	✅ Passed	All modifications are confined to updating the configurable flag on the _path property within the middleware template, and there are no unrelated or extraneous changes beyond the linked issue’s scope.
Description Check	✅ Passed	The pull request description directly explains the HMR error and the solution of adding configurable: true to the property definitions, aligning clearly with the changes implemented and remaining fully on-topic.
Docstring Coverage	✅ Passed	No functions found in the changes. Docstring coverage check skipped.

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📜 Recent review details

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📥 Commits

Reviewing files that changed from the base of the PR and between 011c13e and 495334c.

📒 Files selected for processing (1)

• packages/nuxt/src/core/templates.ts (2 hunks)

🧰 Additional context used

📓 Path-based instructions (1)

**/*.{ts,tsx}

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Follow standard TypeScript conventions and best practices

Files:

• packages/nuxt/src/core/templates.ts

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• GitHub Check: test-fixtures (ubuntu-latest, built, vite, default, manifest-off, json, lts/-1)
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🔇 Additional comments (2)

packages/nuxt/src/core/templates.ts (2)

348-348: Correct fix for HMR property redefinition.

Adding configurable: true allows the _path property to be safely redefined during Hot Module Replacement, preventing the TypeError "Cannot redefine property: _path" when CSS changes trigger module reloads.

---

359-359: Consistent application of configurable property.

The configurable: true addition mirrors the fix for global middleware, ensuring both global and named middleware support HMR property redefinition. This provides complete coverage for the issue across all middleware types.

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commit: 495334c

[codspeed-hq]

CodSpeed Performance Report

Merging #33379 will not alter performance

_{Comparing Flo0806:fix/middleware-hmr-redefine-property (495334c) with main (011c13e)}

Summary

✅ 10 untouched