Fix Vite config plugin imports and add resolveId hook filter

[masenf]

Type of change

• Bug fix (non-breaking change which fixes an issue)

Changes To Core Features

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your core changes, as applicable?

Description

This PR fixes two issues in the Vite configuration template:

1. Plugin import extension: Changed the local plugin import from "./vite-plugin-safari-cachebust" to "./vite-plugin-safari-cachebust.js" to include the file extension. Vite's native config loader (planned to become the default) cannot resolve extensionless relative imports and warns about them.

2. resolveId hook optimization: Refactored the alwaysUseReactDomServerNode plugin's resolveId hook to use Vite's hook filter API. The hook now declares filter: { id: /react-dom\/server/ } to prevent the hook from being called for every import in the module graph. Without this filter, rolldown calls the hook for tens of thousands of imports, which dominates build time on large applications. The redundant source.includes("react-dom/server") check was removed since the filter now ensures only matching imports reach the handler.

Test Plan

Added two new unit tests in tests/units/utils/test_utils.py:

• test_vite_config_template_imports_plugin_with_extension(): Verifies the plugin import includes the .js extension
• test_vite_config_template_filters_react_dom_server_resolve_hook(): Verifies the resolveId hook declares the filter and handler

Both tests call vite_config_template() and assert the expected strings are present in the generated config.

https://claude.ai/code/session_01PXbBjFDmFjqYQPHdPjk4zp

[greptile-apps]

Greptile Summary

The PR updates the generated Vite configuration to use an explicit JavaScript extension for the local Safari plugin and a filtered object-form resolveId hook.

• Adds the .js extension required by Vite’s native config loader.
• Narrows React DOM server resolution to matching module identifiers.
• Adds regression tests and performance news fragments.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
packages/reflex-base/src/reflex_base/compiler/templates.py	Updates the generated Vite plugin import and converts the React DOM resolver to a filtered hook while retaining the importer guard.
tests/units/utils/test_utils.py	Adds assertions covering the explicit plugin extension and filtered resolve hook output.
news/6959.performance.md	Documents the generated-config compatibility and performance improvements.
packages/reflex-base/news/6959.performance.md	Records the package-level Vite configuration changes and their performance rationale.

_{Reviews (2): Last reviewed commit: "Drop the expository comment from the gen..." | Re-trigger Greptile}

[cubic-dev-ai]

No issues found across 2 files

_{Re-trigger cubic}

[codspeed-hq]

Merging this PR will not alter performance

✅ 27 untouched benchmarks
⏩ 8 skipped benchmarks¹

---

_{Comparing claude/reflex-docs-macos-timeout-d3ucaj (67ffa40) with main (a4d99be)}

Footnotes

1. 8 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩