Fix Vite config plugin imports and add resolveId hook filter

news/6959.performance.md

@@ -0,0 +1 @@
+The generated `vite.config.js` now declares a hook filter on the plugin that redirects `react-dom/server` to `react-dom/server.node`, so the bundler no longer calls into it for every import in the module graph — on the Reflex docs site that was ~15,800 calls per build to rewrite a single specifier. The local plugin import in the config also carries a file extension now, silencing Vite's warning about features its native config loader cannot resolve.

packages/reflex-base/news/6959.performance.md

@@ -0,0 +1 @@
+`vite_config_template` declares a `resolveId` hook filter (`{ id: /react-dom\/server/ }`) on `vite-plugin-always-use-react-dom-server-node`. The plugin runs with `enforce: "pre"`, so without a filter rolldown invoked its JS handler for every import specifier in the graph (~15,800 calls on the Reflex docs build) to redirect the one specifier imported by `entry.server.node.tsx`; the filter is evaluated natively and skips the call otherwise. The template also imports `./vite-plugin-safari-cachebust.js` with its extension, which Vite's `configLoader: "native"` requires and warns about today.

packages/reflex-base/src/reflex_base/compiler/templates.py

@@ -655,25 +655,27 @@ def vite_config_template(
     return rf"""import {{ fileURLToPath, URL }} from "url";
 import {{ reactRouter }} from "@react-router/dev/vite";
 import {{ defineConfig }} from "vite";
-import safariCacheBustPlugin from "./vite-plugin-safari-cachebust";
+import safariCacheBustPlugin from "./vite-plugin-safari-cachebust.js";
 
 // Ensure that bun always uses the react-dom/server.node functions.
 function alwaysUseReactDomServerNode() {{
   return {{
     name: "vite-plugin-always-use-react-dom-server-node",
     enforce: "pre",
 
-    resolveId(source, importer) {{
-      if (
-        typeof importer === "string" &&
-        importer.endsWith("/entry.server.node.tsx") &&
-        source.includes("react-dom/server")
-      ) {{
-        return this.resolve("react-dom/server.node", importer, {{
-          skipSelf: true,
-        }});
-      }}
-      return null;
+    resolveId: {{
+      filter: {{ id: /react-dom\/server/ }},
+      handler(source, importer) {{
+        if (
+          typeof importer === "string" &&
+          importer.endsWith("/entry.server.node.tsx")
+        ) {{
+          return this.resolve("react-dom/server.node", importer, {{
+            skipSelf: true,
+          }});
+        }}
+        return null;
+      }},
     }},
   }};
 }}

tests/units/utils/test_utils.py

@@ -885,6 +885,43 @@ def test_vite_config_template_pins_preview_host() -> None:
     assert 'host: "127.0.0.1",' in config
 
 
+def test_vite_config_template_imports_plugin_with_extension() -> None:
+    """Local plugin imports carry a file extension.
+
+    Vite's native config loader (planned to become the default) cannot resolve
+    extensionless relative imports and warns about them today.
+    """
+    from reflex.compiler import templates as compiler_templates
+
+    config = compiler_templates.vite_config_template(
+        base="/",
+        hmr=True,
+        force_full_reload=False,
+        experimental_hmr=False,
+        sourcemap=False,
+    )
+    assert 'from "./vite-plugin-safari-cachebust.js"' in config
+
+
+def test_vite_config_template_filters_react_dom_server_resolve_hook() -> None:
+    """The react-dom/server resolveId hook declares a hook filter.
+
+    Without a filter, rolldown calls the hook for every import in the module
+    graph, which dominates build time on large apps.
+    """
+    from reflex.compiler import templates as compiler_templates
+
+    config = compiler_templates.vite_config_template(
+        base="/",
+        hmr=True,
+        force_full_reload=False,
+        experimental_hmr=False,
+        sourcemap=False,
+    )
+    assert "filter: { id: /react-dom\\/server/ }," in config
+    assert "handler(source, importer) {" in config
+
+
 @pytest.mark.parametrize("minify", [True, False])
 def test_compile_vite_config_reads_minify_env(
     minify: bool, monkeypatch: pytest.MonkeyPatch