Ignore injected plugin context when using Environment API

Author: markdalgleish

packages/react-router-dev/vite/plugin.ts

@@ -601,33 +601,36 @@ export const reactRouterVitePlugin: ReactRouterVitePlugin = () => {
 
   /** Mutates `ctx` as a side-effect */
   let updatePluginContext = async (): Promise<void> => {
+    let reactRouterConfig: ResolvedReactRouterConfig;
+    let reactRouterConfigResult = await reactRouterConfigLoader.getConfig();
+
+    if (reactRouterConfigResult.ok) {
+      reactRouterConfig = reactRouterConfigResult.value;
+    } else {
+      logger.error(reactRouterConfigResult.error);
+      if (firstLoad) {
+        process.exit(1);
+      }
+      return;
+    }
+
     // This `injectedPluginContext` logic is so we can support injecting an
     // already-resolved plugin context into the build. This is so we can resolve
     // the plugin context once for the entire build process and avoid resolving
     // it every time the Vite config is resolved. This is most important for
     // resolving the `buildManifest` object since it involves executing the
     // `serverBundles` function, which we want to avoid doing multiple times.
+    // Note that this logic is redundant when using the Vite Environment API
+    // since our plugin is instantiated once and shared across all builds.
     let injectedPluginContext =
+      !reactRouterConfig.future.unstable_viteEnvironmentApi &&
       viteCommand === "build"
         ? extractPluginContext(viteUserConfig)
         : undefined;
     if (injectedPluginContext) {
       ctx = injectedPluginContext;
     }
 
-    let reactRouterConfig: ResolvedReactRouterConfig;
-    let reactRouterConfigResult = await reactRouterConfigLoader.getConfig();
-
-    if (reactRouterConfigResult.ok) {
-      reactRouterConfig = reactRouterConfigResult.value;
-    } else {
-      logger.error(reactRouterConfigResult.error);
-      if (firstLoad) {
-        process.exit(1);
-      }
-      return;
-    }
-
     let { entryClientFilePath, entryServerFilePath } = await resolveEntryFiles({
       rootDirectory,
       reactRouterConfig,