From a930ad4b915ab6f9a36ed9ddc2c193bd60d6c8d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=ABl=20Charles?= <joel.charles91@gmail.com>
Date: Tue, 20 Aug 2024 12:00:04 +0200
Subject: [PATCH] fix: forbid isr + edge for same endpoint. fixes #102

---
 packages/vercel/src/build.ts      |  7 +++++++
 packages/vike-integration/vike.ts | 18 ++++++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/packages/vercel/src/build.ts b/packages/vercel/src/build.ts
index d5cd9e2..edb801a 100644
--- a/packages/vercel/src/build.ts
+++ b/packages/vercel/src/build.ts
@@ -355,6 +355,13 @@ export async function buildEndpoints(resolvedConfig: ResolvedConfig): Promise<{
           );
         }
 
+        if (
+          (entry.isr !== undefined || exports.isr !== undefined) &&
+          (entry.edge !== undefined || exports.edge !== undefined)
+        ) {
+          throw new Error(`isr cannot be enabled for edge functions ('${entry.source}')`);
+        }
+
         if (exports.isr) {
           entry.isr = exports.isr;
         }
diff --git a/packages/vike-integration/vike.ts b/packages/vike-integration/vike.ts
index cf2e09e..ec11c26 100644
--- a/packages/vike-integration/vike.ts
+++ b/packages/vike-integration/vike.ts
@@ -110,7 +110,7 @@ function assertEdge(exports: unknown): boolean | null {
   return edge;
 }
 
-function assertIsr(resolvedConfig: UserConfig | ResolvedConfig, exports: unknown): number | null {
+function extractIsr(exports: unknown) {
   if (exports === null || typeof exports !== "object") return null;
   if (!("isr" in exports)) return null;
   const isr = (exports as { isr: unknown }).isr;
@@ -127,6 +127,13 @@ function assertIsr(resolvedConfig: UserConfig | ResolvedConfig, exports: unknown
     " `{ expiration }` must be a positive number",
   );
 
+  return isr;
+}
+
+function assertIsr(resolvedConfig: UserConfig | ResolvedConfig, exports: unknown): number | null {
+  const isr = extractIsr(exports);
+  if (isr === null || isr === undefined) return null;
+
   if (isr === true) {
     assert(
       typeof resolvedConfig.vercel?.expiration === "number" && resolvedConfig.vercel?.expiration > 0,
@@ -421,17 +428,24 @@ export function vitePluginVercelVikeConfigPlugin(): Plugin {
             }
 
             const route = getRouteDynamicRoute(pageRoutes, pageId) ?? getRouteFsRoute(pageRoutes, pageId);
+            const rawIsr = extractIsr(page.config);
             let isr = assertIsr(userConfig, page.config);
             const edge = assertEdge(page.config);
 
             // if ISR + Function routing -> warn because ISR is not unsupported in this case
             if (typeof route === "function" && isr) {
               console.warn(
-                `Page ${pageId}: ISR is not supported when using route function. Remove \`{ isr }\` export or use a route string if possible.`,
+                `Page ${pageId}: ISR is not supported when using route function. Remove \`{ isr }\` config or use a route string if possible.`,
               );
               isr = null;
             }
 
+            if (edge && rawIsr !== null && typeof rawIsr === "object") {
+              throw new Error(
+                `Page ${pageId}: ISR cannot be enabled for edge functions. Remove \`{ isr }\` config or set \`{ edge: false }\`.`,
+              );
+            }
+
             return {
               _pageId: pageId,
               // used for debug purpose