fix(cli): keep own properties of promise plugins in defineConfig

packages/cli/src/__tests__/define-config-plugins.spec.ts

@@ -176,6 +176,16 @@ describe('defineConfig project plugin injection', () => {
     ]);
   });
 
+  // https://github.com/voidzero-dev/vite-plus/issues/3152
+  it('keeps async plugins as-is so their own properties survive', () => {
+    // Mirrors `vike()`, which tags its plugin promise for config discovery.
+    const vikePlugin = Object.assign(Promise.resolve([{ name: 'vike' }]), {
+      _vikeVitePluginOptions: {},
+    });
+    const config = defineConfig({ plugins: [vikePlugin] });
+    expect(config.plugins![4]).toBe(vikePlugin);
+  });
+
   it('injects nested independent projects in referenced defineProject configs', () => {
     const config = defineProject({
       test: {

packages/cli/src/define-config.ts

@@ -851,8 +851,9 @@ function withoutVitePlusTestPlugins(plugin: PluginOption): PluginOption {
   if (Array.isArray(plugin)) {
     return plugin.filter(keepUserPlugin).map(withoutVitePlusTestPlugins);
   }
+  // Injected plugins are never async, and re-wrapping with `.then` drops own props that tools like Vike look up.
   if (plugin instanceof Promise) {
-    return plugin.then(withoutVitePlusTestPlugins);
+    return plugin;
   }
   return plugin && VITE_PLUS_TEST_PLUGIN_NAMES.has(plugin.name) ? false : plugin;
 }