fix: map route segment revalidate to Nitro routeRules SWR

packages/vinext/src/build/nitro-route-rules.ts

@@ -0,0 +1,121 @@
+import { appRouter, type AppRoute } from "../routing/app-router.js";
+import { apiRouter, pagesRouter, type Route } from "../routing/pages-router.js";
+import { buildReportRows, type RouteRow } from "./report.js";
+
+// Mirrors Nitro's NitroRouteConfig — hand-rolled because nitropack is not a direct dependency.
+export type NitroRouteRuleConfig = Record<string, unknown> & {
+  swr?: boolean | number;
+  cache?: unknown;
+  static?: boolean;
+  isr?: boolean | number;
+  prerender?: boolean;
+};
+
+export type NitroRouteRules = Record<string, { swr: number }>;
+
+/**
+ * Scans the filesystem for route files and generates Nitro `routeRules` for ISR routes.
+ *
+ * Note: this duplicates the filesystem scanning that `printBuildReport` also performs.
+ * The `nitro.setup` hook runs during Nitro initialization (before the build), while
+ * `printBuildReport` runs after the build, so sharing results is non-trivial. This is
+ * a future optimization target.
+ *
+ * Unlike `printBuildReport`, this path does not receive `prerenderResult`, so routes
+ * classified as `unknown` by static analysis (which `printBuildReport` might upgrade
+ * to `static` via speculative prerender) are skipped here.
+ */
+export async function collectNitroRouteRules(options: {
+  appDir?: string | null;
+  pagesDir?: string | null;
+  pageExtensions: string[];
+}): Promise<NitroRouteRules> {
+  const { appDir, pageExtensions, pagesDir } = options;
+
+  let appRoutes: AppRoute[] = [];
+  let pageRoutes: Route[] = [];
+  let apiRoutes: Route[] = [];
+
+  if (appDir) {
+    appRoutes = await appRouter(appDir, pageExtensions);
+  }
+
+  if (pagesDir) {
+    const [pages, apis] = await Promise.all([
+      pagesRouter(pagesDir, pageExtensions),
+      apiRouter(pagesDir, pageExtensions),
+    ]);
+    pageRoutes = pages;
+    apiRoutes = apis;
+  }
+
+  return generateNitroRouteRules(buildReportRows({ appRoutes, pageRoutes, apiRoutes }));
+}
+
+export function generateNitroRouteRules(rows: RouteRow[]): NitroRouteRules {
+  const rules: NitroRouteRules = {};
+
+  for (const row of rows) {
+    if (
+      row.type === "isr" &&
+      typeof row.revalidate === "number" &&
+      Number.isFinite(row.revalidate) &&
+      row.revalidate > 0
+    ) {
+      rules[convertToNitroPattern(row.pattern)] = { swr: row.revalidate };
+    }
+  }
+
+  return rules;
+}
+
+/**
+ * Converts vinext's internal `:param` route syntax to Nitro's `/**` glob
+ * pattern format. Nitro's `routeRules` use radix3's `toRouteMatcher` which
+ * documents exact paths and `/**` globs, not `:param` segments.
+ *
+ *   /blog/:slug   -> /blog/**
+ *   /docs/:slug+  -> /docs/**
+ *   /docs/:slug*  -> /docs/**
+ *   /about        -> /about  (unchanged)
+ */
+export function convertToNitroPattern(pattern: string): string {
+  return pattern.replace(/\/:([a-zA-Z_][a-zA-Z0-9_-]*)([+*]?)(\/|$)/g, "/**$3");
+}
+
+export function mergeNitroRouteRules(
+  existingRouteRules: Record<string, NitroRouteRuleConfig> | undefined,
+  generatedRouteRules: NitroRouteRules,
+): {
+  routeRules: Record<string, NitroRouteRuleConfig>;
+  skippedRoutes: string[];
+} {
+  const routeRules = { ...existingRouteRules };
+  const skippedRoutes: string[] = [];
+
+  for (const [route, generatedRule] of Object.entries(generatedRouteRules)) {
+    const existingRule = routeRules[route];
+
+    if (existingRule && hasUserDefinedCacheRule(existingRule)) {
+      skippedRoutes.push(route);
+      continue;
+    }
+
+    routeRules[route] = {
+      ...existingRule,
+      ...generatedRule,
+    };
+  }
+
+  return { routeRules, skippedRoutes };
+}
+
+function hasUserDefinedCacheRule(rule: NitroRouteRuleConfig): boolean {
+  return (
+    rule.swr !== undefined ||
+    rule.cache !== undefined ||
+    rule.static !== undefined ||
+    rule.isr !== undefined ||
+    rule.prerender !== undefined
+  );
+}

packages/vinext/src/index.ts

@@ -9,6 +9,7 @@ import {
 import { generateServerEntry as _generateServerEntry } from "./entries/pages-server-entry.js";
 import { generateClientEntry as _generateClientEntry } from "./entries/pages-client-entry.js";
 import { appRouter, invalidateAppRouteCache } from "./routing/app-router.js";
+import type { NitroRouteRuleConfig } from "./build/nitro-route-rules.js";
 import { createValidFileMatcher } from "./routing/file-matcher.js";
 import { createSSRHandler } from "./server/dev-server.js";
 import { handleApiRoute } from "./server/api-handler.js";
@@ -1168,6 +1169,16 @@ export interface VinextOptions {
   };
 }
 
+interface NitroSetupContext {
+  options: {
+    dev?: boolean;
+    routeRules?: Record<string, NitroRouteRuleConfig>;
+  };
+  logger?: {
+    warn?: (message: string) => void;
+  };
+}
+
 export default function vinext(options: VinextOptions = {}): PluginOption[] {
   const viteMajorVersion = getViteMajorVersion();
   let root: string;
@@ -4369,6 +4380,40 @@ export default function vinext(options: VinextOptions = {}): PluginOption[] {
         },
       };
     })(),
+    {
+      name: "vinext:nitro-route-rules",
+      nitro: {
+        setup: async (nitro: NitroSetupContext) => {
+          if (nitro.options.dev) return;
+          if (!nextConfig) return;
+          if (!hasAppDir && !hasPagesDir) return;
+
+          const { collectNitroRouteRules, mergeNitroRouteRules } =
+            await import("./build/nitro-route-rules.js");
+          const generatedRouteRules = await collectNitroRouteRules({
+            appDir: hasAppDir ? appDir : null,
+            pagesDir: hasPagesDir ? pagesDir : null,
+            pageExtensions: nextConfig.pageExtensions,
+          });
+
+          if (Object.keys(generatedRouteRules).length === 0) return;
+
+          const { routeRules, skippedRoutes } = mergeNitroRouteRules(
+            nitro.options.routeRules,
+            generatedRouteRules,
+          );
+
+          nitro.options.routeRules = routeRules;
+
+          if (skippedRoutes.length > 0) {
+            const warn = nitro.logger?.warn ?? console.warn;
+            warn(
+              `[vinext] Skipping generated Nitro routeRules for routes with existing exact cache config: ${skippedRoutes.join(", ")}`,
+            );
+          }
+        },
+      },
+    } as Plugin & { nitro: { setup: (nitro: NitroSetupContext) => Promise<void> } }, // Nitro plugin extension convention: https://nitro.build/guide/plugins
     // Vite can emit empty SSR manifest entries for modules that Rollup inlines
     // into another chunk. Pages Router looks up assets by page module path at
     // runtime, so rebuild those mappings from the emitted client bundle.