Don't output CSS on Next server builds (#852)

Author: mattcompiles

.changeset/spicy-planes-approve.md

@@ -0,0 +1,7 @@
+---
+'@vanilla-extract/next-plugin': patch
+---
+
+Fix `Cannot find module *.css.ts.vanilla.css` issue
+
+Previously, CSS was being output on both the client and server builds. This fix ensure CSS is only output on the client build.

packages/next-plugin/src/index.js

@@ -50,7 +50,9 @@ export const createVanillaExtractPlugin =
           ),
         });
 
-        config.plugins.push(new VanillaExtractPlugin(pluginOptions));
+        config.plugins.push(
+          new VanillaExtractPlugin({ outputCss: !isServer, ...pluginOptions }),
+        );
 
         if (typeof nextConfig.webpack === 'function') {
           return nextConfig.webpack(config, options);