Skip action-only resource routes with prerender:true (#13004)

Author: brophdawg11

.changeset/late-nails-hear.md

@@ -0,0 +1,5 @@
+---
+"@react-router/dev": patch
+---
+
+Skip action-only resource routes when using `prerender:true`

.changeset/rotten-numbers-bathe.md

@@ -0,0 +1,5 @@
+---
+"@react-router/dev": patch
+---
+
+Limit prerendered resource route `.data` files to only the target route

integration/vite-prerender-test.ts

@@ -344,6 +344,42 @@ test.describe("Prerendering", () => {
       expect(html).toMatch('<p data-loader-data="true">About Loader Data</p>');
     });
 
+    test("Skips action-only resource routes prerender:true", async () => {
+      let buildStdio = new PassThrough();
+      fixture = await createFixture({
+        buildStdio,
+        files: {
+          "react-router.config.ts": reactRouterConfig({
+            prerender: true,
+          }),
+          "vite.config.ts": files["vite.config.ts"],
+          "app/root.tsx": files["app/root.tsx"],
+          "app/routes/_index.tsx": files["app/routes/_index.tsx"],
+          "app/routes/action.tsx": js`
+            export function action() {
+              return null
+            }
+          `,
+        },
+      });
+
+      let buildOutput: string;
+      let chunks: Buffer[] = [];
+      buildOutput = await new Promise<string>((resolve, reject) => {
+        buildStdio.on("data", (chunk) => chunks.push(Buffer.from(chunk)));
+        buildStdio.on("error", (err) => reject(err));
+        buildStdio.on("end", () =>
+          resolve(Buffer.concat(chunks).toString("utf8"))
+        );
+      });
+
+      expect(buildOutput).toContain(
+        "⚠️ Skipping prerendering for resource route without a loader: routes/action"
+      );
+      // Only logs once
+      expect(buildOutput.match(/routes\/action/g)?.length).toBe(1);
+    });
+
     test("Pre-renders resource routes with file extensions", async () => {
       fixture = await createFixture({
         prerender: true,
@@ -385,9 +421,6 @@ test.describe("Prerendering", () => {
 
       let dataRes = await fixture.requestSingleFetchData("/json.json.data");
       expect(dataRes.data).toEqual({
-        root: {
-          data: null,
-        },
         "routes/json[.json]": {
           data: {
             hello: "world",
@@ -400,9 +433,6 @@ test.describe("Prerendering", () => {
 
       dataRes = await fixture.requestSingleFetchData("/text.txt.data");
       expect(dataRes.data).toEqual({
-        root: {
-          data: null,
-        },
         "routes/text[.txt]": {
           data: "Hello, world",
         },

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

@@ -2317,21 +2317,6 @@ async function handlePrerender(
       matches,
       `Unable to prerender path because it does not match any routes: ${path}`
     );
-    let hasLoaders = matches.some(
-      (m) => build.assets.routes[m.route.id]?.hasLoader
-    );
-    let data: string | undefined;
-    if (hasLoaders) {
-      data = await prerenderData(
-        handler,
-        path,
-        clientBuildDirectory,
-        reactRouterConfig,
-        viteConfig,
-        { headers }
-      );
-    }
-
     // When prerendering a resource route, we don't want to pass along the
     // `.data` file since we want to prerender the raw Response returned from
     // the loader.  Presumably this is for routes where a file extension is
@@ -2340,21 +2325,53 @@ async function handlePrerender(
     let leafRoute = matches ? matches[matches.length - 1].route : null;
     let manifestRoute = leafRoute ? build.routes[leafRoute.id]?.module : null;
     let isResourceRoute =
-      manifestRoute &&
-      !manifestRoute.default &&
-      !manifestRoute.ErrorBoundary &&
-      manifestRoute.loader;
+      manifestRoute && !manifestRoute.default && !manifestRoute.ErrorBoundary;
 
     if (isResourceRoute) {
-      await prerenderResourceRoute(
-        handler,
-        path,
-        clientBuildDirectory,
-        reactRouterConfig,
-        viteConfig,
-        { headers }
-      );
+      invariant(leafRoute);
+      invariant(manifestRoute);
+      if (manifestRoute.loader) {
+        // Prerender a .data file for turbo-stream consumption
+        await prerenderData(
+          handler,
+          path,
+          [leafRoute.id],
+          clientBuildDirectory,
+          reactRouterConfig,
+          viteConfig,
+          { headers }
+        );
+        // Prerender a raw file for external consumption
+        await prerenderResourceRoute(
+          handler,
+          path,
+          clientBuildDirectory,
+          reactRouterConfig,
+          viteConfig,
+          { headers }
+        );
+      } else {
+        viteConfig.logger.warn(
+          `⚠️ Skipping prerendering for resource route without a loader: ${leafRoute?.id}`
+        );
+      }
     } else {
+      let hasLoaders = matches.some(
+        (m) => build.assets.routes[m.route.id]?.hasLoader
+      );
+      let data: string | undefined;
+      if (!isResourceRoute && hasLoaders) {
+        data = await prerenderData(
+          handler,
+          path,
+          null,
+          clientBuildDirectory,
+          reactRouterConfig,
+          viteConfig,
+          { headers }
+        );
+      }
+
       await prerenderRoute(
         handler,
         path,
@@ -2408,6 +2425,7 @@ function getStaticPrerenderPaths(routes: DataRouteObject[]) {
 async function prerenderData(
   handler: RequestHandler,
   prerenderPath: string,
+  onlyRoutes: string[] | null,
   clientBuildDirectory: string,
   reactRouterConfig: ResolvedReactRouterConfig,
   viteConfig: Vite.ResolvedConfig,
@@ -2418,7 +2436,11 @@ async function prerenderData(
       ? "/_root.data"
       : `${prerenderPath.replace(/\/$/, "")}.data`
   }`.replace(/\/\/+/g, "/");
-  let request = new Request(`http://localhost${normalizedPath}`, requestInit);
+  let url = new URL(`http://localhost${normalizedPath}`);
+  if (onlyRoutes?.length) {
+    url.searchParams.set("_routes", onlyRoutes.join(","));
+  }
+  let request = new Request(url, requestInit);
   let response = await handler(request);
   let data = await response.text();